# Tecumseh LH358SA Runs Rough after 45 minutes using



## dk56 (Feb 20, 2019)

2008 Husqvarna 10527SB-LS Snow Thrower with Tecumseh LH358SA-159647A engine. Engine has always run fine until now. Everything on the snow thrower is working fine right now. It gets a lot of miles -- equivalent of 500 ft driveway including dirt & gravel & grass areas. Far northern NY near Lake Champlain/Canada; i.e., frequent usage.

While clearing the last two snow events, after running for about 45-60 minutes, engine started surging mildly and acting like it was going to stall, especially when I was not moving. When I drive ahead into fresh snow, it recovers for the most part under load. Stop moving, and it starts faltering again. Eventually, it seems to just run weak with a load, too, as if bogged down, but still works.

I had already replaced the spark plug for the season, but replaced it again after first incident. Second incident ruled out the plug.

I have always added Sta-bil immediately to newly filled gas cans ... within an hour. And the gas used right now is only a few weeks old. I keep everything clean and lubed. Oil changed around every 12 hours running. Book says 25 hours.

If I let it cool off for a while, it runs okay. After the first incident I let it run for 30 min test after replacing the plug and oil (the oil was already recently changed, too). 30-min. test okay, but wasn't next time it snowed ... trouble in 45 min. Was nearly done for the day because it was only 5" light fluffy stuff so I was able to move fast. Finished shortly after it started acting up. Let it run while cleaning it, and it was erratic. Shut it down, let it cool half an hour, ran fine.

It still starts like a charm just as it always did. One or two pulls, the usual prime & choke routine. Never used the electric starter ... no juice in the shed.

I think go for the breather first, but once I take it apart that far, I feel like maybe I should take the shotgun approach and give it a 10th birthday overhaul ... replace carb, breather, fuel lines, flush out the gas tank, replace coil, muffler and the associated gaskets. MAYBE. Because it's a 75-minute test between each cure I try, and I'd have to wait for parts in the mail between each try.

I don't see a fuel filter or pump, but will replace them if I find them when it's apart.

I've never had the cover off the engine, so we haven't made friends yet, and I never wanted to, but I can do this stuff at gunpoint, and no machine in a snowstorm is gunpoint. Really prefer not to pay somebody else and end up with no fix anyway. Good help is hard to get. One time I let the dealer work on it they broke it two ways. It was the last time.

Here's where you come in. Any experience with this kind of temperamental engine? Any really common, typical known cause and fix?

Thoughts on putting carb cleaner additive into the gas and run it for an hour? (I think that would be a very long shot.)

I might just replace the breather foam and clean the carb (properly).

Thing is, I don't have much time between snow storms to get to it whenever the parts arrive (RepairClinic.com has them all in stock.) 

The biggest thing baffling me is _*how any fuel or air issue could show up only after running for a long time*_, then go away until next time it's run for a long time, apparently more than 30 min.

Could the coil be acting up only after being hot for a long period?

Any thoughts much appreciated before I get out the shotgun dollars or experiment with gas additive, letting it run for an hour ... twice.

Thanks.


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## Kiss4aFrog (Nov 3, 2013)

:welcome: to SBF dk56

.


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## Jackmels (Feb 18, 2013)

Valve Clearances


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## RedOctobyr (Mar 2, 2014)

Jackmels said:


> Valve Clearances


My thought as well, especially because it takes time to develop, but goes away once the engine cools. 

The Tecumsehs can develop too-small valve clearances over time (with use). The valves apparently kind of hammer into their seats a bit, so they sit a little too far back. 

The valve clearances need to be in a certain range. Too-small, and the valves can be held open slightly, due to thermal expansion, as the engine gets hot. This reduces compression & power, since the combustion chamber isn't being fully closed as the engine fires. It can also damage the valve or its seat, over time. If the clearances are too-large, the compression release can't do its job properly, so the engine can be physically harder to pull-start (or electric start). 

Checking clearances is not difficult, and doesn't really require special tools. But you do need a set of flat feeler gauges. Adjusting clearances is a bit more involved. But check them first, at least. 

An example of feeler gauges, which would also be available at an auto parts store: 
https://www.amazon.com/Hotop-Blades-Feeler-Imperial-Measuring/dp/B06XHXJG31/ref=sr_1_1_sspa?ie=UTF8&qid=1550705900&sr=8-1-spons&keywords=feeler+gauges&psc=1

This Tecumseh's Technician's Manual is a good reference, especially if you know what procedure you need to do. 

https://www.snowblowerforum.com/forum/snowblower-repairs-maintenance-forum/1383-tecumseh-technicians-handbook-4-stroke.html


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## Dannoman (Jan 16, 2018)

When a machine works fine for a while then starts acting up it might be a faulty gas cap. Try running it with your cap loosened but still on, or with a piece of plastic with a hole in it covering the hole. If it runs okay then you might have a faulty gas cap which does not vent. That vacuum it creates stops the fuel from entering the system and starves your carb. You can drill a small hole in the defective cap in the meantime until you pick up a new replacement cap. It happened to me last year.


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## RedOctobyr (Mar 2, 2014)

Dannoman said:


> When a machine works fine for a while then starts acting up it might be a faulty gas cap.


Good point, shame on me for not thinking about that. It's a very easy thing to test for, too. 


One way to check for this is to run until you have the problem. Then either shut down briefly (not really required), or just quickly loosen the gas cap (enough that air can get in), and then tighten it down again. If it suddenly runs fine for a while, you have a plugged gas cap, which is not venting correctly. 

The advantage to checking this way is you can be sure whether it fixes your problem. If you just loosen the cap, or drill it, and then try running, you have a harder time proving it's fixed. If the problem doesn't appear, it might be because of the fixed gas cap, or maybe you just got lucky. But if you wait and reproduce the problem, and then allow the tank to vent (unscrew the cap), you can see if it's suddenly better. And if it *doesn't* help, you know that too. 

To test the cap more quickly, fill the tank as full as you're comfortable with. The less air in the tank, the more quickly you'll draw a vacuum, and starve for fuel. Then try running it, either blowing snow, or just letting it run in the driveway, if needed, until the problem happens.


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## Jackmels (Feb 18, 2013)

A fuel venting issue would appear MUCH faster than 45 minutes. My 2 cents.


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## Dannoman (Jan 16, 2018)

RedOctobyr said:


> Good point, shame on me for not thinking about that. It's a very easy thing to test for, too.
> 
> 
> One way to check for this is to run until you have the problem. Then either shut down briefly (not really required), or just quickly loosen the gas cap (enough that air can get in), and then tighten it down again. If it suddenly runs fine for a while, you have a plugged gas cap, which is not venting correctly.
> ...



Good advice Red.


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## dk56 (Feb 20, 2019)

Thanks for the clear and thorough explanation, RedO. Seems to me I used to have a flat feeler gauge cluster. Must've disappeared with my timing light when I stopped replacing points & condensers in cars. I've never had the head off any engine, though. Will look at the manual and explore from there. Not sure I'm prepared to do this but I'm prepared to find out. DIY: learning to learn what needs to be learned and doesn't, and paying for the education.


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## RedOctobyr (Mar 2, 2014)

The head doesn't have to come off to check clearances. You just remove the little crankcase breather cover, and check them there. Also the spark plug, so you can set the piston height correctly.


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## dk56 (Feb 20, 2019)

Thanks, Dannoman. Funny thing ... a couple of years ago I lost the gas cap. Always figured it would show up in the spring near the shed. Never did. Anyhow, I made one out of tin foil and a rubber band until the new one came in the mail. Worked fine. Since then the cap always goes into my pocket or on the bench every time it comes off the tank. Never set it on the machine. Like tire valve caps.

I see what you mean about venting/pressure. So does this thing use gravity feed or a fuel pump somewhere under the cover?

And thanks again RedO. Love the simplicity of this test! I usually fill the gas until it barely touches the bottom of the neck. I'll bring it up all the way into the neck and let it run for an hour.

I looked at the gas cap the other day but I'll have to look again for anything awry when I fill it up for this test.


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## RedOctobyr (Mar 2, 2014)

These are gravity fed, no fuel pump.

If you fill the tank all the way, I agree with Jackmels, I wouldn't expect it to take an hour to draw a vacuum and starve for gas.


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## dk56 (Feb 20, 2019)

Jackmels said:


> A fuel venting issue would appear MUCH faster than 45 minutes. My 2 cents.


Thanks, Jackmels.

I've been wondering why a heat-related problem would take so long. Doesn't the engine reach full temp pretty quickly? Like a few minutes?

Glad the gas cap thing is so easy to test. Back atchyall soon.


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## dk56 (Feb 20, 2019)

Thanks, Red. Glad to hear that. One less possible culprit.


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## dk56 (Feb 20, 2019)

RedOctobyr said:


> The head doesn't have to come off to check clearances. You just remove the little crankcase breather cover, and check them there. Also the spark plug, so you can set the piston height correctly.


Thanks. Will read up before opening the tool box. Probably can find a YouTube vid of it, too.


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## Lottstodo (Feb 16, 2018)

You say replace breather foam. As in a air filter, on a snow series engine?

I would remove the foam and run it. The norm is snow series engines do not use a filter that can plug with snow or ice crystals just for that reason. So if in fact you have a air filter I would question why , and not run it during use in the snow.


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## SayItAintSnow (Dec 15, 2017)

Lottstodo said:


> _You say replace breather foam. As in a air filter, on a snow series engine?
> 
> __ I would remove the foam and run it. The norm is snow series engines do not use a filter that can plug with snow or ice crystals just for that reason. So if in fact you have a air filter I would question why , and not run it during use in the snow_.



Exactly.... but it depends on what the O/P is calling a "breather"....


DK56, 



Are you saying there is a foam filter covering the carb like you'd find on a lawnmower?
Like Lotts' was saying, that would be unusual on a blower. A foam filter keeps dust and dirt out of your carb on a mower or lawn tractor for instance, but snowblowers typically don't operate in dusty environments.


Worse yet, as moist air is drawn in rapidly through the intake, below freezing temps can turn that collected moisture into a barrier of ice in the foam, and starve the engine of air, making your fuel/air ratio all wrong, making your machine run like crap.


BTW, can you post a picture of this breather part you are referring to?
.


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## Lottstodo (Feb 16, 2018)

I did work on a blower a while ago , that someone had replaced the engine with one off of a lawn tractor , and it did have a filter housing with a filter in it. It would only run blowing snow until the filter plugged and killed it. Thats why I asked.

It now has a snow series engine on it.


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## SayItAintSnow (Dec 15, 2017)

Lottstodo said:


> _I did work on a blower a while ago , that someone had replaced the engine with one off of a lawn tractor , and it did have a filter housing with a filter in it. It would only run blowing snow until the filter plugged and killed it. Thats why I asked._



Yeah.........When I read his description of the problems, and he mentioned the "foam" I was thinking _"Hey wait a minute....Is this the original snow duty type engine on there, or has someone done a transplant from some other type of P/E"?_ 

Maybe he'll post a picture.....
.
.


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## dk56 (Feb 20, 2019)

Thanks for all the feedback and education everyone.

Gas cap ruled out. Dang.

This is the original engine and I'm the original owner. Nobody has worked on the engine. I've done all the other repairs.

I read that an oil overfill could foul the breather and cause rough running. I'm not overfilled, but that's what raised the notion that maybe there is a breather issue. So I went looking for hey what is a breather anyway and found this "filter."

Three parts dealers I checked list the matching factory part number from the parts list.

Parts diagram -- see attached file, item 171.

"Breather element:"









Assuming the trouble is valve clearance, would it be sort of normal for rough running to smooth out when the governor kicks in / load applied? (Went to buy feeler gauges for my valve clearance OJT and they were out. Will be in tomorrow.)

Thanks again.


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## SayItAintSnow (Dec 15, 2017)

dk56 said:


> _Thanks for all the feedback and education everyone._
> 
> _Gas cap ruled out. Dang.
> 
> ...



O.K......that's good. Just wanted to make sure we weren't chasing a problem of different terminologies. 

And by the way, since you found that foam piece in the breather circuit, it is likely that has been in there since the engine was built, and is a good idea you had to replace it. :thumbsup:

Not surprised about the gas gap. I've experienced that kind of problem before, and it generally raised its ugly head in more like 10 minutes or less rather than 45 minutes to an hour.

So we're back to valves......:icon_scratch:

Here's a good video from Donyboy73 demonstrating how to check clearances on a flat head TEC, which explains things better than I certainly could. It's not that difficult, and the visual should help to give you the confidence to dive in and give it shot.






*Good luck with that, and let us know how you made out! *:wink2:


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## RedOctobyr (Mar 2, 2014)

In my Tecumsehs, that breather filter isn't really foam in the traditional sense. Mine are more like a mesh of plasticky fibers. I didn't feel bad about re-using mine, they didn't seem like something that would degrade. They aren't like an air filter, they'd only try to catch big stuff. 

I'm not sure about whether valves would make it smooth out when the throttle open, during a load. Maybe. With a bigger air/fuel charge being burned, even if some % is leaking past the valve, maybe the bigger burn helps it still maintain a certain level of cylinder pressure.


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## Lottstodo (Feb 16, 2018)

Ok glad you were talking about crankcase breather , and not and air filter.

Have you been able to ohm test the coil / ignition module when it starts to do this.


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## SayItAintSnow (Dec 15, 2017)

RedOctobyr said:


> In my Tecumsehs, that breather filter isn't really foam in the traditional sense. Mine are more like a mesh of plasticky fibers. I didn't feel bad about re-using mine, they didn't seem like something that would degrade. They aren't like an air filter, they'd only try to catch big stuff.



Right....I've never run up against anything in that application that looked like "foam" either.....more like a screen that you can clean up. It would seem that foam would be a bad idea since it would foul pretty quickly. I'm wondering if the o/p actually saw this part on the machine or is assuming it to be foam from a parts diagram. :confused2:

.
.


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## 3vanman (Nov 21, 2017)

Just an idea, have you drained the fuel tank entirely, and checked the filter screen inside the tank? You mentioned lots of mile and hours on this machine..is it possible there may be a foreign object in the tank that eventually blocks the fuel flow? I had a similar problem a couple of months ago on a machine I was working on, found a small amount of "crud" would eventually settle onto the fuel screen..I'd take it back in, let it sit, fill it with fuel and it would run fine..Just an idea


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## dk56 (Feb 20, 2019)

Thanks everyone. Each of you has given me good things to look into. I'll do them all ... when I get done with big interference made urgent by procrastination and a surprise invasion of my solitude, and when the minimal parts needed get here, like the breather element ("filter") and gaskets I see on the diagram. Don't want to take it apart and not be prepared to replace that kind of thing.

SayItAintSnow, I love Donyboy. Subscriber. He's been a big help to me before. Would have gone to him first for a video. Thanks for doing it for me.

RedOctobyr, yes, for that part number vendors show that green meshy stuff, which RepairClinic calls "foam" in that picture I posted. The parts list calls it "breather element" with an image of a seeming undersized rectangular block of something they don't describe further.

Lottstodo, I'll ohm-test the coil. Thanks for the good idea. 0 ohms, yes?

3vanman, thanks. The diagram shows a fuel filter below the tank, but I don't see one. If I find one hidden, it definitely gets replaced or cleaned if metal. The engine falters just standing still, but maybe something is vibrating in and out of the way. I'll do the tank screen cleaning regardless. Will see what happens with a little pulling, shoving and tipping first, to see if ...

You're all generous with your time, info and guidance. I appreciate it.

-DK


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## cranman (Jan 23, 2016)

I just had a Honda acting like that...turned out the coil would get weak when hot.....just use it and when it cuts out check the spark.....if its the coil, it will probably test OK when cold.


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## dk56 (Feb 20, 2019)

cranman said:


> I just had a Honda acting like that...turned out the coil would get weak when hot.....just use it and when it cuts out check the spark.....if its the coil, it will probably test OK when cold.


Thanks cranman. I just ordered a spark tester that will let me easily watch the spark with the engine running. Maybe I'll see a spark difference during the time the engine is stumbling.

BTW, my pain-calibrated shoulders say I don't have significant compression loss 'cuz it still hurts to pull the starter cord. Those joints need a rebuild, but DIY ain't gonna cut it.


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## RedOctobyr (Mar 2, 2014)

Good idea with the inline spark tester. They're a great way to check for things like this, and they're not very expensive, but most people don't have them. It should be a nice way to help understand what's going on. 

If you want to try something before it arrives, let it get hot and weak, then shut it down and quickly check for spark. Maybe it'll be gone/weak. Another thing I've tried is reducing the spark plug gap by maybe half (just as a test), to make it easier for the spark to jump. If the problem suddenly goes away, that would seem consistent with a coil getting weak when hot.


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## Fat City (Feb 11, 2017)

I'd start by re-torquing cylinder head . Agree with other posters on coil, gas cap vent, valve adjustment .


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## dk56 (Feb 20, 2019)

RedOctobyr said:


> Good idea with the inline spark tester.


Tester will be here later today. Meanwhile, I'm heading out now in 3 deg. F & windy to take out 2 ft. drifts from yesterday's 4" accum & wicked wind. I think it will run well enough, even if it means stopping for a cool-down once.


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## dk56 (Feb 20, 2019)

Fat City said:


> I'd start by re-torquing cylinder head . Agree with other posters on coil, gas cap vent, valve adjustment .


Thanks for another simple thing to do ... and for ensuring I get to use my brand new torque wrench that I wanted on-hand before doing anything to the engine. (Dad's not available anymore.) I understand how to approach re-torque.

Got new feeler gauge for valves. 

Will have to find the valve clearance and head torque specs. Have not been through all the manuals suggested but so far I don't see specs for my engine model LH358SA.

Not sure I really want to remove the valve springs 2, 3 or 4 times to adjust without the spring tool. Maybe I can rent one. Or send it to a shop if the clearances are bad.

None of the valve job videos I saw say HOW MUCH out of spec % is tolerable for valve clearance? All the examples seem to show 0 clearance cases needing fix.

Anyone?

All of the suggestions given here are good things to check no matter what the solution ends up being. Thanks again.


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## RedOctobyr (Mar 2, 2014)

I guess the simple answer is if it's out of spec, it should be fixed. They've already given an acceptable range, of 0.004-0.008", for instance, for some engines. 

You don't necessarily have to remove the valve to add clearance. In other the threads about clearances, people have described using a thin file to modify the back of the valve, with it still installed. I think JackMels has mentioned this. 

I removed mine, measured the length with digital calipers, and took enough off the length to make it correct. One iteration. Though since I didn't have the spring compressor, it was a pain to remove/install.


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## cranman (Jan 23, 2016)

A thin file will do the job with the valves still installed...no biggy.


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## Grunt (Nov 11, 2013)

Your LH358 is the same as a HM100 or HMSK100 motor, meaning it is 10hp. The valve specs are .008 to .012 clearance. The specs can be found on page 101 of this manual.
It is more common to find the clearances to small rather than to large since the valves wear into the seats and reduce clearances. If the exhaust valve clearance is to large, it defeats the compression release and makes it difficult to pull start the motor. If the clearances are to small, the valves expand from the heat and will cause the engine to run rough and/or pop through the muffler because the valves don't close completely.
http://www.barrettsmallengine.com/manual/tecumsehlheadmanual.pdf


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## dk56 (Feb 20, 2019)

Grunt said:


> Your LH358 is the same as a HM100 or HMSK100 motor ...[/URL]


Thanks. I found that chart just before finding your message ... and learned about the HM equivalent somewhere else. Appreciate your confirming it!

These two numbers on the chart .008 and .012 are intake and exhaust, respectively, right? Not a _range_ of .008 to .012.


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## dk56 (Feb 20, 2019)

Grunt said:


> If the clearances are to small, the valves expand from the heat and will cause the engine to run rough and/or pop through the muffler because the valves don't close completely.
> http://www.barrettsmallengine.com/manual/tecumsehlheadmanual.pdf


I do get frequent "popping," but it's done some of that for as long as I can remember. That is, I can't remember when it started. Could be it has grown gradually worse and I haven't noticed the increase.

Well, the temp outside is all the way up to 6, so it's time to work on yesterday's snow drifts. See how that spark looks with the new tester when it starts failing.


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## RedOctobyr (Mar 2, 2014)

dk56 said:


> These two numbers on the chart .008 and .012 are intake and exhaust, respectively, right? Not a _range_ of .008 to .012.


I'm pretty sure that's the acceptable range, 0.008-0.012", and the same value applies to both valves.


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## Fat City (Feb 11, 2017)

I'm thinking, ' it's the coil ' Bring a spark tester with you, check spark when running good [ baseline ] Test spark as soon as it conks out [ compare ] The way I see it ... if it was a lawn mower [ hot ] the coil would act up quickly . Cold engines heat slowly, once engine is hot enough, coil falters, and performance drops off . What about Mag Kills ? Could their be a corroded mag kill [ plastic key safety cut off ] Throttle bracket , Dash mounted kill [ key ] switch .



Always check the cheap, easy fixes first, they cost the least, and bring the most satisfaction .


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## dk56 (Feb 20, 2019)

Fat City said:


> What about Mag Kills ? Could their be a corroded mag kill ... Throttle bracket ...


I'll examine/clean these when I have the cover off.


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## dk56 (Feb 20, 2019)

RedOctobyr said:


> I'm pretty sure that's the acceptable range, 0.008-0.012", and the same value applies to both valves.


I ask because all the videos I've seen for valve work on these flat head engines talk about a separate intake and exhaust spec. The intake is always smaller than the exhaust. .006 & .010 or .008 & .012, etc.

For example, look at this donyboy73 beginning at 1:40 ...

https://youtu.be/yQiE50YAPuA?t=100


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## RedOctobyr (Mar 2, 2014)

Good question. 

This seems to list the same info, but explicitly states it's the "Intake and Exhaust Valve Clearance" min and max values: 
Tecumseh Engine Intake and Exhaust Valve Clearances 

And this Tecumseh Quick Reference shows values for Intake, and for Exhaust, with spec ranges: 
https://lookup3.toro.com/ttcGateway/acrobat/manuals/tecqkref.pdf

An engine that showed 0.004" and 0.008" in the other manual shows 0.006" +/- 0.002" in this. It's somewhat misleading to express it two different ways, but they are both saying the same thing. That somewhere between 0.004" and 0.008" is in-spec, and acceptable.


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## rminnehan (Nov 21, 2013)

If you had a gas cap problem you wouldn't get 45 minutes of use out of it before dying out and it wouldn't start working better "under load" as you say. It would die out. It seems that having a valve issue after 45 minutes would be very odd. If you haven't already, pull the engine cover off and see what it looks like under there; make sure there are no mouse nests causing the engine to overheat or a chewed up coil wire and while you have the cover off, replace the coil. They are cheap enough. Secondly, where it picks back up under load it could be a carburetor/fuel issue so if the problem persists I would clean and rebuild the carburetor, clean and flush the fuel system and replace the fuel lines, just to eliminate that system. If you still have the problem bring it to someone who has some experience in servicing those machines.


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## ST1100A (Feb 7, 2015)

If your engine is an overhead valve engine, it is most likely an LCT engine. A Chinese engine company that bought out Tecumseh when they went out of business a decade or so ago. Every on of those engines are very poorly built with no quality control whatsoever. Every one of those engines on Husqvarna snowblowers that I have worked on had that same problem you are having. The problem on almost 100 of those engines I repaired was a tight intake valve clearance related problem. Some were brand new out of the box units, others only had a few hours on them. LCT/Tecumseh uses very poor materials in manufacturing and they have zero quality control in their manufacturing process that would catch the problem when the engines are assembled. Check both the intake and exhaust valve clearance and re adjust as needed. That should help with your power loss when the engine gets hot. Husqvarna used to be a decent manufacturer back in the 70's, but not anymore. I would stay as far away from anything they make or has their name on it as possible. Maybe in the next decade they might realize their profit margines are falling and then may start building better machines.


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## Jackmels (Feb 18, 2013)

ST1100A said:


> If your engine is an overhead valve engine, it is most likely an LCT engine. A Chinese engine company that bought out Tecumseh when they went out of business a decade or so ago. Every on of those engines are very poorly built with no quality control whatsoever. Every one of those engines on Husqvarna snowblowers that I have worked on had that same problem you are having. The problem on almost 100 of those engines I repaired was a tight intake valve clearance related problem. Some were brand new out of the box units, others only had a few hours on them. LCT/Tecumseh uses very poor materials in manufacturing and they have zero quality control in their manufacturing process that would catch the problem when the engines are assembled. Check both the intake and exhaust valve clearance and re adjust as needed. That should help with your power loss when the engine gets hot. Husqvarna used to be a decent manufacturer back in the 70's, but not anymore. I would stay as far away from anything they make or has their name on it as possible. Maybe in the next decade they might realize their profit margines are falling and then may start building better machines.


Had you taken the time to look up the engine number, You would have found it an L-head Tecumseh, and could have saved your long winded reply.


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## Lottstodo (Feb 16, 2018)

I would really like to know where and how you arrive at the fact that LCT engines are poorly built!!!
I do not believe Ariens and other good MFG would compromise the companies integrity by not doing extensive test on the quality performance and durability of the LCT engine. 
Every single problem I have seen in the LCT engines that I have repaired or replaced has been owner neglect or misuse related. With the exception of the occasional faulty part. 
To be honest I have to repair more Briggs and Tecs than I do LCT. Are they my favorite engine no, however I own 3 and they run right there with my 6 Briggs and 4 Hondas and 2 Tecs , 3 Kohlors,.
You Quoted this about a LTC when it was actually a L-Head Tec.


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## dk56 (Feb 20, 2019)

RedOctobyr said:


> This seems to list the same info, but explicitly states it's the "Intake and Exhaust Valve Clearance" min and max values:
> Tecumseh Engine Intake and Exhaust Valve Clearances
> 
> And this Tecumseh Quick Reference shows values for Intake, and for Exhaust, with spec ranges:
> ...


Thanks very much for digging them up. They definitely give it as ranges. I'll go with that (.008 - .012 for my LH358SA a.k.a. HMSK110).

Wonder why a sharp guy like donyboy plainly says "the manual for this engine [Tec 10hp like mine] indicates that the intake valve should have a clearance of .008 and the exhaust valve .012." Maybe I'll drop him a line.

Thanks again.


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## dk56 (Feb 20, 2019)

rminnehan said:


> If you had a gas cap problem you wouldn't get 45 minutes of use out of it before dying out and it wouldn't start working better "under load" as you say. It would die out. It seems that having a valve issue after 45 minutes would be very odd. If you haven't already, pull the engine cover off and see what it looks like under there; make sure there are no mouse nests causing the engine to overheat or a chewed up coil wire and while you have the cover off, replace the coil. They are cheap enough. Secondly, where it picks back up under load it could be a carburetor/fuel issue so if the problem persists I would clean and rebuild the carburetor, clean and flush the fuel system and replace the fuel lines, just to eliminate that system. If you still have the problem bring it to someone who has some experience in servicing those machines.


Thanks for spending some time on this. I intend to do almost all of your list, but slow to replace the coil. $64+shipping. (Somebody will say they can get it for less. So can I. And are they quoting the right thing?) In-line spark tester shows a good blue-white stream when the engine is surging/stumbling, same as when it's running okay.


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## dk56 (Feb 20, 2019)

FYI, yes, it's a Tec L-head, and maybe the last one they made! DOM says it was made on the 301st day of 2008. This Husqvarna 27" snow thrower Model 10527SB-LS was made by AYP, as they did for Craftsman.

For clarification: It's a Tecumseh 358 cc L-head, 11 hp, Model LH358SA-159647A per the engine label; a.k.a. per manuals HMSK110 (Horizontal Medium frame Snow King 11.0 hp) and I confess I am actually Frosty the Snow Man yet not a-scared-a-no-snowblower.


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## dk56 (Feb 20, 2019)

P.S.: Despite great weather, I didn't work on the Orange Beast today because I could only get rid of my house guests for a few hours and spent a couple hours fixing the short-cycling water pump, for which I declare, "Victory!" But working in the 4-ft. crawl space does a number on my back. So I'm just a cyber-snow-man for tonight.


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## vinnycom (Nov 6, 2017)

dont throw parts at it until u can duplicate or source the problem.
what happens if u start closing the choke when motor starts to run rough.
it seems like its either starving for fuel or its got too much air. why after 45mins? idk


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## dk56 (Feb 20, 2019)

vinnycom said:


> dont throw parts at it until u can duplicate or source the problem.
> what happens if u start closing the choke when motor starts to run rough.
> it seems like its either starving for fuel or its got too much air. why after 45mins? idk


Thanks for your input.

Starts normally, have to open the choke immediately. There are four steps on the choke knob. Runs same (slight difference sometimes) on 1 & 2 (open). Move to 3 or 4 (closed) and it dies, as expected. Same whether it's running okay or rough.


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## ST1100A (Feb 7, 2015)

If you noticed the very first word "If", referring to a problem with engines with tight valve clearance problems that I encounter quite frequently. I just repaired another 2008 Husqvarna 11hp snowblower today with the same problem. Tight valve clearance. I normally set the valve clearance on the loose side, especially the intake valve, it will actually cause the compression to build a little bit higher and give a little bit more power while running. 2008 was around the time of some engine change overs with Tecumseh. They were going through various ownership and kept changing names and manufacturing plants. It was very confusing. The snowblower I repaired today was one with an LCT/Tecumseh engine, overhead valve. A flat head engine around that year was not the original Tecumseh that most of us were used to back in the 70's and 80's. Many of those 2000 and later. engines were made overseas because the U.S. outlawed a lot of those engines because they did not meet emission requirements, thanks to the EPA. I'm sorry if I confused people on my previous post, I have been working in the small engine industry too long.


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## ST1100A (Feb 7, 2015)

Lottstodo said:


> I would really like to know where and how you arrive at the fact that LCT engines are poorly built!!!
> I do not believe Ariens and other good MFG would compromise the companies integrity by not doing extensive test on the quality performance and durability of the LCT engine.
> Every single problem I have seen in the LCT engines that I have repaired or replaced has been owner neglect or misuse related. With the exception of the occasional faulty part.
> To be honest I have to repair more Briggs and Tecs than I do LCT. Are they my favorite engine no, however I own 3 and they run right there with my 6 Briggs and 4 Hondas and 2 Tecs , 3 Kohlors,.
> You Quoted this about a LTC when it was actually a L-Head Tec.


Probably from repairing hundreds of them and sending out many metal parts to have them analyzed at a local University/Steel mill laboratory to check for defective metal components, which not many people have access to. A lot of things today are manufactured as cheap as possible. Its not "quality" anymore, it is "quantity" that the manufacturers are after. All they think of is their profits and the heck with the consumer anymore, thats why we live in a "throw away" society. A lot of the "old timers" that I deal with are used to the old machinery that lasted for quite a long time, like a lot of old time Gravely owners. Areins and many other companies went downhill with their quality over the years due to their making profits and heck with their customers. We have all noticed that. LCT is a rather new company so they are just comming out now,unlike Briggs who has been around for years. Did you know that at this time most Briggs engines are made in China? Briggs is in the process right now of bringing their manufacturing back to the USA at this time. All of their new Intek engines are made in their China plant. Maybe thanks to Donald Trump they are bringing them back to the USA. Honda did the same mistake years ago with their GC series engines being made in China, they were nothing but trouble. Honda finally realized the problems they were having with them and cancelled the contract with the manufacturer and brought them back to Japan and the USA. A lot of these "Big Box Store" companies extensive testing is a joke compared to decades ago when things were made here and quality was number one, now days their profit is number one to them and the heck with the consumer.


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## SnowH8ter (Oct 8, 2018)

ST1100A said:


> Probably from repairing hundreds of them and sending out many metal parts to have them analyzed at a local University/Steel mill laboratory to check for defective metal components, which not many people have access to.


:facepalm_zpsdj194qh My Bovine Excreta (BS) meter is beeping...


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## Lottstodo (Feb 16, 2018)

As cited by MovingSnow. com

By the way, LCT is a U.S. company and has been around for over 25 years. LCT has a proven track record of quality and engineering excellence with hundreds of thousands of engines sold to world-class OEMs and retailers in North America alone. Their extensive service network is supported by the Lauson Power Company who is well known for providing the highest standards of customer satisfaction. LCT engines are engineered in the U.S. Just like the Briggs & Stratton snow engines and Powermore snow engines they are made offshore. LCT makes their own engines and they own their own factories. LCT is engineered as a new generation of power and reliability for all of your power equipment needs. (Lauson is America’s oldest engine company)
HOMEOUTDOOR POWER EQUIPMENTWho Makes Ariens AX Engines?
OUTDOOR POWER EQUIPMENTWho Makes Ariens AX Engines? Paul
Who Makes Ariens AX Engine? LCT. (Liquid Combustion Technology)

LCT is one of the best snow blower engines on the market. When Tecumseh quit making engines, they took that technology and gave it the refinements that were sorely needed for snow engines. Today’s LCT engines are arguably the best snow engine for dependability, starting, and power for cc’s.


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## Lottstodo (Feb 16, 2018)

Sorry OP , for the rabbit trail on LCTs engines.

Now for yours , 
I have encountered 2 things in the past that would be easy to check that on these machines had similar problems as what you have.

1) someone had replaced gas lines on a craftsman that ended up being to long which put enough bend on the line that when the engine got warm/ hot would soften the fuel line and would bend or flex to the point that it restricted / reduced fuel to the carb almost pinching it off. When the line cooled off it actually would reopen enough to get sufficient fuel again.

2) Another machine I found had a ground problem to the coil and at times would lose most of the ground. First thought was the coil of course but ohm'd fine. found there was just enough corrosion at the mount that when it got warm it would let it go to weak ground. ( weak grounds are very popular and a major cause of a lot of auto related problems) so it may be worth a look. Even the spark tester did not show this when we used it.

Again this is not saying that this is your problem just maybe something to look at.


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