# Snowblower won't start



## redbeard (Mar 6, 2017)

Hi everyone, 
I am hoping to get some help on an older snowblower that I have. I have done a lot of searching, but am stuck. I live in a small Northern town in Canada and we do not have any small repairs shops here, so I am stuck doing it myself which I don’t mind. It’s kind of fun, but it is time consuming! The snowblower I have is a Yard Works 60-3754-4 with a Tecumseh engine model LH358SA. The problem of course is that it will not start. Here is what I did so far in no particular order:


· Confirmed that the snowblower key is in the machine 
 

· Changed spark plug. Used a Champion RJ19LM
 

· Confirmed that I am getting a spark. I can’t find my spark plug tester, but when I grab a hold of the spark plug and pull the cord, I get shocked. 
 

· Completely removed carburetor and cleaned it. I do not have a carburetor repair kit at any local stores, but all the gaskets looks great. I cleaned the jet, plastic float was good, etc.
 

· I tried to pour a little gas (a teaspoon) into the spark plug hole to see if I could get anything and all I got was a little smoke. Didn’t really start. 
 

· Confirmed that there is gas going to the carburetor as when I prime it and press the drain plug, gas comes pouring out
 I think that is about it. The one thing that I cannot find online is how exactly that snowblower “key” works. I see some wires coming where the key gets put into the snowblower, but is there a way to test that there isn’t a short somewhere or that the wire isn’t frayed in a place that I cannot see? Thanks everyone.


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## e.fisher26 (Nov 6, 2016)

The key when removed will ground out the spark. Does it have electric start?


-efisher-


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## micah68kj (Oct 8, 2011)

Welcome to "da place". 
Try resting the plug on a unpainted spot on the head and pull the rope and check for a bright blue spark there. If spark is present leave your plug out and pull rope a few times. Put a very small amount of motor oil. In the spark hole( less than a teaspoon) and pull rope a few times to allow oil to get on cyl walls. This eleminates possibility of washdown. Make sure plug is dry and properly gapped and reinstall. Press primer 3 times, set choke and it should start 
right up.
When you cleaned your carb did you check those tiny holes in the jet screw? This pic shows them..
If all else fails....
http://www.ebay.com/bhp/tecumseh-carburetor


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## 43128 (Feb 14, 2014)

whats the story as to why it isnt running now, that will help us diagnose it


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## Sblg43 (Jan 18, 2014)

You may also want to check the flywheel key. You may be getting spark but it might be sparking at the wrong time. You will of course have to remove the flywheel to check the key.


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## RIT333 (Feb 6, 2014)

Since you get a puff of smoke, plus a shock on your hand, the key is not the problem, so you don't have to sorry about that.

With the plug out, you may want to put your thumb over the spark plug hole. You should feel some suction proving that you have compression. Without sufficient compression, it will not pull gas from the carburetor. You can salso try spraying some starting ether into the carb to see if it will run for a few seconds and then quit. That will point to a fuel issue, and probably not a bad/bent flywheel key.


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## redbeard (Mar 6, 2017)

Thanks everyone, I will try those suggestions when I get back from work tonight. I'm glad the key isn't the problem. As for why it didn't start, there isn't much of a story. It worked one year, then after the winter I stored it (drained the gas, removed the spark plug), and next winter it didn't work. I was in the process of moving so didn't really have time to mess with it. I just started looking at it recently. Thanks again.


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## RIT333 (Feb 6, 2014)

I re-thinking the key. The key could be off a little, and it would still fire, but at the wrong time, so you may have to check that. Sorry for getting your hopes up !


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## classiccat (Mar 1, 2014)

+1 on checking compression and the flywheel key


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## RedOctobyr (Mar 2, 2014)

Sblg43 said:


> You may also want to check the flywheel key. You may be getting spark but it might be sparking at the wrong time. *You will of course have to remove the flywheel to check the key.*


Not necessarily. This thread had some discussion of ways to try and check the flywheel key without removing the flywheel itself: 

http://www.snowblowerforum.com/forum/snowblower-repairs-maintenance-forum/110906-pull-flywheel-not-pull-flywheel-briggs-8hp.html

I would still do the suggested test of laying the plug against the engine block, and pulling the cord, to watch for a spark. It should be bright blue. You don't need to find your ignition tester to check the plug/ignition. 

If it used to be OK, and now won't start, that usually points to a fuel-related problem. But there could certainly be something else going on, especially if adding some fuel/ether doesn't get it to run for a few seconds.


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## e.fisher26 (Nov 6, 2016)

Disconnect the key wire and the lead from the throttle from where they meet at the isolator to rule out a short. Or disconnect the lead from the coil also.. (if it comes to that) a weak spark COULD be an issue.


Sent from my iPhone using Tapatalk


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## redbeard (Mar 6, 2017)

Hi, 
So I have tried the suggestions with no luck. 
1. Definitely a blue spark when up against an unpainted part of the snowblower
2. Lots of compression when I put my thumb over the spark plug hole and pull.
3. Even tried starter fluid and nothing.

One thing I should have mentioned, is that the original electric starter went bad at the end of the last winter it was working. It still worked fine with the pull though. I did buy the correct starter and replaced it just like I have done with a vehicle multiple times. But now that I am having issues, it seems like it just doesn't sound the same when trying to pull start it. Less smooth and more "clanky" if that makes sense. I never really noticed it until today, completely forgot about it until now. I've removed the starter for now though and just have the pull start. Sorry


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## RIT333 (Feb 6, 2014)

Sounds like you're going to have to inspect the flywheel key.


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## RedOctobyr (Mar 2, 2014)

The flywheel key being sheared would definitely make it not start. Another thing you could check would be to remove the valve cover on the side of the engine, and make sure the valves are operating properly. 

In the thread I linked to earlier, he had a valve that wasn't opening. His is an OHV engine, not an L-head like yours, and an OHV is probably more susceptible to this. But if a valve isn't opening for some reason, the engine can't actually bring in a fresh air/fuel charge.


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## RIT333 (Feb 6, 2014)

RedOctobyr said:


> The flywheel key being sheared would definitely make it not start. Another thing you could check would be to remove the valve cover on the side of the engine, and make sure the valves are operating properly.
> 
> In the thread I linked to earlier, he had a valve that wasn't opening. His is an OHV engine, not an L-head like yours, and an OHV is probably more susceptible to this. But if a valve isn't opening for some reason, the engine can't actually bring in a fresh air/fuel charge.


Would you still have good compression with a valve issue ?


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## RedOctobyr (Mar 2, 2014)

I think it depends. If the valves were staying open, you'd get no compression. 

But if, for example, the exhaust valve was never opening at all, then you could get compression. The intake valve opens, the piston goes down, the cylinder "inhales", intake closes, then compression stroke happens, with the proper amount of air. So you get compression. 

But if the exhaust valve never opened, then it wouldn't run, because without flow through the engine, you're not really drawing new fuel and air into it. You're mainly just compressing the same air/fuel charge over and over. 

That little cover is 2 screws, as I recall, on the flathead Tecumsehs, it could be worth a look. It's easier than removing the flywheel, at least, and I prefer to start with the easy things, even if they seem unlikely.


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## redbeard (Mar 6, 2017)

I had a look at the valves, and to be honest I am not sure what I am looking for. I took a picture of them, but am not sure how to upload it here. I will have a look at the flywheel key tonight, cause I have to buy a bigger socket. The biggest I have is a 22mm.


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## RedOctobyr (Mar 2, 2014)

I would start by looking for both valves to actuate as you pull the starter cord. One should move, then the other. 

For the flywheel, removing the nut, as well as the flywheel, can both be tricky. If you have an impact gun, that's a great way to get the nut off safely. Otherwise the engine wants to turn as you use a wrench on the nut. 

Sometimes people will stick something into the cooling fins on the flywheel to prevent the flywheel from turning, but this can break off a fin. An impact wrench avoids this problem. Otherwise if you have a strap wrench, that's a safe way to prevent it from turning. 

Then popping the flywheel off the tapered shaft can be tricky, if you don't have a flywheel puller. There are various methods that people use. But if you just use a crowbar to pry it away from the engine, to pop it off, you can punch a hole in the engine block. 

For reinstalling the flywheel nut, use a torque wrench, and torque the nut properly per the Tecumseh service manual. Make sure the tapered surfaces (crankshaft & flywheel) are clean and dry, do not lubricate them. The friction between them, with the proper torque, keeps the flywheel where it's supposed to be. Not enough torque, or lubricated tapers, and the flywheel can spin on the crankshaft, shearing off the flywheel key. Too much torque, and the flywheel can split due to the taper. 

If you have feeler gauges, having the valve cover off is a chance to check for proper valve clearance, if you want. This can be a useful thing to check, but actually *changing* the valve clearance is difficult on an L-head engine, so it's one of those things where hopefully you simply find that the valve clearances are in-spec. If the valve clearance is too small, that can result in reduced compression.


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## redbeard (Mar 6, 2017)

Ok, here is a picture of the valves, I can;t seem to include it in this post, but the link is here: https://flic.kr/p/SMCYZK

I'm going to follow this video here: 




Let you know how it goes

FYI, I do have an impact wrench, but would rather make sure the valves are ok before tackling that.


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## RedOctobyr (Mar 2, 2014)

Sounds good. I didn't watch the video, but you don't need to remove the cylinder head to check valve clearances. 

As I recall from the service manual, you want the piston 1/4" down from Top Dead Center (TDC) on the power stroke, to ensure that both valves are fully closed. They should have small gaps between the valves and the rods that open them. 

I don't remove the cylinder head to set the piston height for this test. I usually remove the spark plug, and stick a pencil down through the hole, so it touches the piston. Rotate the crankshaft until piston is all the way up, and both valves are closed. Then rotate the crankshaft a bit more until the pencil drops by 1/4".


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## RedOctobyr (Mar 2, 2014)

By the way, the Tecumseh service (technician's) manual for L-heads is available in one of the stickied threads at the top of the page in this forum.


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## redbeard (Mar 6, 2017)

Hi everyone, I have measured the valve clearance and it doesn't look good. Assuming that I measured it right anyways. I measured the valve clearance from TDC and also from 1/4 inch down like RedOctobyr mentioned. I didn't see the 1/4 inch reference in the manual and that manual doesn't specifically mention my model of engine. I also took the cylinder head off, because why not! I haven't done it before and wanted to see what it was like. Anyways, both measurements were the same, with the Intake at 0.005 and the exhaust at 0.004 which is HUGE difference form what is stated on a few websites which is the Intake @ .008 / and exhaust @ .012. No idea how to fix this if it is the problem, or even how it happened. To recap how I measured, I turned the flywheel until the piston was flush with the top and both valves were also at the top. I think it took two turns of the piston as the valves would move the whole time until the second one. I am going away this weekend, so any advice I will try when I get back on Monday.


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## skutflut (Oct 16, 2015)

Were you able to rotate the valves with your fingers when they were fully closed?

Inspect the valve seats (the sealing surface in the cylinder) to see if they are nice and smooth and not pitted or burned. Also inspect the valves around the edges on the back side for any signs of pitting or burning and wear. 

If there is damage you might need to either replace or grind or at least lap the valves to get the mating surfaces to seal properly. Grinding might be best left to a competent machine shop since angles are important. Any grinding or lapping of the valves will reduce the clearance even more. 

Once the valves and seats are in good shape, grind the valve stems to get the correct clearance. Then reassemble everything. You will need a new head gasket, and possibly a new valve cover gasket, and any others that were exposed when you disassembled the bits and pieces.


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## RedOctobyr (Mar 2, 2014)

The valves are definitely out of spec. But whether that's enough to make the engine not actually run, I couldn't say. If you have a compression tester, that would tell you something. 

If you're still getting, say, 50psi, I think that would be enough to let it start. If you're getting 10psi, probably not. 

This thread has discussions about grinding valve lengths, to fix clearance issues:

http://www.snowblowerforum.com/foru...ssible-leaking-exhaust-valve-need-advice.html 

But I might hold off on that for now. Checking the compression, or flywheel key, might be worth doing before grinding down the valve lengths. If you still have enough compression, then the valve clearances may not be your problem.


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## skutflut (Oct 16, 2015)

Just out of curiosity, did you find little of no resistance to pulling the engine over with the starter rope? As mentioned in that video, if you are getting no resistance or very little, then valves are likely your problem. However if you are feeling resistance, maybe not. 

You do have some clearance from your measurements, which means the valves should be closing all the way as the stems are clear of the lifters, but if the valves or seats are leaking away that compression, you will have troubles as described.


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## redbeard (Mar 6, 2017)

Hi, I had a little time today to mess around with the snowblower. To answer one question above, no I cannot move the valves when at TDC or even a 1/4 below TDC. I can only move the valves when they are open. I also had a look at the flywheel key and it looks good. Here are some pics, https://flic.kr/p/SJ1PUs & https://flic.kr/p/SJ1PXU 

And just for fun, here is a picture of the piston and valves from the top looking down. https://flic.kr/p/SJ2A1J

I haven't checked the compression yet, but after doing a little research on that, will my snowblower have a decompression release ? A video on Youtube mentioned that, and it looked very similar to my snowblower. Although it did offer some insight to what I should get even if I had a decompression release. 

When pulling the rope, I did have some resistance but will check for 100% sure tomorrow. I'm going to put the snowblower together tomorrow and check the compression then as well.

Thanks!


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## RedOctobyr (Mar 2, 2014)

I would expect the engine to have a compression release, yes. That's good that you can't turn the valves at TDC. Though that doesn't guarantee that their seats are in good-shape, I think it more indicates that yes, you have valve clearance. 

That's good to know that the flywheel key is intact. Though to be honest, it'd be nice if it was sheared off, since that's a $1 fix, and you've already done all the labor  

At this point: 
- You've checked and gotten a blue spark, with the plug pulled
- You've confirmed the valves are operating
- You've checked the flywheel key, and thus your ignition timing
- You've gotten nothing, even with starter fluid

You need spark, fuel, and compression. It sounds like you have the first two, which starts pointing the finger towards compression. 

I've tried temporarily reducing the spark plug gap, just in case the ignition was having a hard time bridging the gap when under compression (which makes a spark more difficult). You said you've tried swapping plugs, so that's done. I don't think you mentioned an inline spark tester, so we don't know that it's sparking when installed. Thinking about something like a bad spark plug wire that happens to make contact when you pulled the plug for a test, but didn't make contact correctly when you reinstalled the plug. 

Maybe the compression check will show something. Because otherwise, it sounds like you're checking off a lot of the boxes of things to investigate.


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## redbeard (Mar 6, 2017)

Does the carburetor have to be put back on for the compression test?


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## RedOctobyr (Mar 2, 2014)

No. If it *is* on the engine, turn the choke off, and go to full throttle. This will help let air into the cylinder. 

I usually pull it quickly a few times until the number stops rising. Don't use any extensions or adapters if you can help it. You'll get more accurate readings with the hose screwed directly into the plug hole.


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## redbeard (Mar 6, 2017)

Ok, so after cutting the compression adapter, because the threads were way too long, I got 60PSI. That is normal, right?


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## RedOctobyr (Mar 2, 2014)

I don't know a "normal" range. But it sounds good to me. Certainly plenty to start the engine. 

My Tecumseh OHV engine (different design than your flathead) starts and runs well with a 30psi compression test result, when pulling the cord by hand (I got 80 psi with using the electric start).

So at this point, I'd try again and see if it runs. Maybe something you did in your work improved the compression. Because if it still won't go, I'd start looking really hard at the ignition and plug. An inline spark tester could be enlightening. 

As mentioned yesterday, things are indicating that you *do* have spark, fuel, and compression. You at least have fuel by squirting some in, and it still didn't start. So it *should* start. And if it doesn't, then we're missing something.


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## redbeard (Mar 6, 2017)

I'm picking up an inline sparkplug tester tonight and will put the whole thing back together as you said. See where that leads me I guess. So far, the only thing that I can see wrong with the snowblower was the valve clearances.


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## redbeard (Mar 6, 2017)

Hello, 
I bought an inline spark tester and everything was fine. So I put the the whole thing back together and guess what? It didn't start! I pulled and pulled and pulled. Nothing. Now, this snowmblower has always been fussy when starting with the pull start so I always used the electric start. I had that electric start off since the beginning of this adventure, and installed it again. Hooked it up to the power and lo and behold, the snowblower started! Something I did must have been good enough to start it. BUT....there was one issue that I noticed. Maybe during my fiddling around with the snowblower and ripping the carburetor on and off multiple times, I may have screwed up the throttle control arm a bit. For the snowblower to start I had to manually adjust the governor. The lever would not work. I checked the spring and there seems to be tension pushing the governor into the high position, but nothing to push it back into low. Is the Governor supposed to have a spring to push back? Because it stays where I leave it. One problem after another.....


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## Bluejoe (Nov 29, 2016)

Well you have it all apart. Bring piston down check cylinder walls for scoring. If not double check value clearance. Remove valves and clean seats then lap valves for good seating. If you good with the lash measurements file or use grinding wheel at end. Just be careful not to much cause it doesn't take much. Clean area and top of piston. Reinstall valves and head with new gasket. The rest is down hill. Your almost there.


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## skutflut (Oct 16, 2015)

redbeard said:


> Maybe during my fiddling around with the snowblower and ripping the carburetor on and off multiple times, I may have screwed up the throttle control arm a bit. For the snowblower to start I had to manually adjust the governor. The lever would not work. I checked the spring and there seems to be tension pushing the governor into the high position, but nothing to push it back into low. Is the Governor supposed to have a spring to push back? Because it stays where I leave it. One problem after another.....


With the engine off, the throttle plate on the carb is held fully open by the governor mechanism. You should not see any action on the governor until the engine is running, at which time the throttle plate will close most of the way at idle, and open a bit more at full throttle. All the pushing and pulling of the governor is based on the internal governor gear and centrifugal weights inside the engine, which press on that rod that comes out of the engine and rotates that governor arm that connects to the carb linkage. The throttle control that you use to slow down and speed up the engine does not actually connect to the carb, but adjusts the spring tension of another spring that counteracts the governor lever. 

When you get into a pile of snow, the governor will sense the engine speed beginning to slow down, and open the throttle plate more to keep engine speed up. This works pretty well most of the time, until you get into a bigger load than the governor can compensate for. Then its time to back off and go slower.

If you have had the throttle/governor assembly apart several times, you need to check and make sure everything went back in the original holes they were in from the factory. Most carbs have several possible places to hook the linkage to, but for each model and configuration there is only ONE right position. It is critical to get these parts back in the right places. Once you are sure they are, mark the holes with a sharpie or something permanent so you don't have the problem again. If you bent something, you might have to either straighten it out or if its wrecked, replace it.

If you ever removed the governor lever from the rod that comes out of the engine, then you have to put that back together right as well. That adjustment is done with the engine OFF. There are tutorials on the web as to how to adjust that lever with respect to the internal shaft. Donyboy73 has several videos showing adjustments on Tecumseh engines.


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