# Almost working perfect...



## POSAriens (Feb 11, 2017)

First post - and i say this is a great resource.

Have a 17 yo Ariens Sno-Thro 524 with the 5hp Tecumseh (HSSK 50).

Quick background - late last year - started to do the proverbial bogging down under load on top of the classic engine surging. To remedy I did a complete carb rebuild - including Carb Dip, removed Welch plugs to clean every orifice, and installed new plugs etc - a complete rebuild with new parts, new spark plug, etc. That solved the surging and it runs and idles down great once warmed up. At the same time I installed new belts and disk (the one with rubber as it was near worn down.) Drives real nice - all is goodness.

Just received a foot of snow on Thursday and it started losing power again. So hand shovel the 100 foot driveway.

So after lots of searches on this board, I did the following:

1) Governor - adjust the governor with red throttle lever lifted up to max throttle, made sure the governor lever arm was tight then tightended the nut.
2) Cap - loosened the gas cap due to allow air - no impact.
3) Checked RPM's - using Hardline Tach - running at about 3800 RPM - when I engage the auger the RPM barely drops - as soon as I stuck it into 10 inches of powder RPM's started dropping...didn't see if Gov arm was moving though
4) This morning - checked Compression - i believe you can't really due to compression release, but at any rate using a high quality Harbor Freight gauge - it reads in the mid-high 30's - this is after warming the engine for about 10 minutes.

A bit perplexed. So I kept going back to thinking about the Governor - so I what I tried next was putting the red throttle lever down to the off position - moved Gov shaft hard to the right - then pushed the lever over so it was at WOT - then tightened.

It seems to work - but it does lose power a bit - but much better than Thursday night when just looking at the auger made it stop. 

I made a video of the blower this morning showing the governor movement before sticking it into 8 inches of heavy wet snow.

Do you think the amount of power loss is normal? I know there is the exhaust valve clearance issue - and I may tackle that in the spring.

Thanks in advance!


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## skutflut (Oct 16, 2015)

You might be trying to go too fast into that wet stuff. Have you tried at a slower speed forward? 

I would dial that max RPM back to not more than 3700, 3600 would be better. Tecumseh engines have been known to break connecting rods and ventilate the engine case.

I noticed that it seems slow to recover rpms after bogging it down. Did you resassemble the throttle and governor linkage at the bits on the carb exactly in the right holes? These bits and pieces have to be assembled exactly right for a given engine. One wrong hole on the carb butterfly, or incorrect placement of the rod that goes from the throttle control lever to the governor arm can cause problems.

Donyboy73 has excellent videos on Youtube showing in detail how to adjust the governor on Tecumseh engines as well as many other maintenance and repair procedures.


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## POSAriens (Feb 11, 2017)

I was at the 2nd lowest forward speed setting. I'll dial down the rpm though.

Re the linkages, I took pictures of everything before teardown so I know those are fine.

DonyBoy's videos are excellent.

At this time at least it works better than Thursday but it seems something else is amiss...


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## JayzAuto1 (Jul 25, 2016)

POS, Next step, verify compression reading with another gauge. Even with compression release, it should hit a strong 40 psi on one engine revolution. if it doesn't, and you have the ability, do a cylinder leakdown test. If you can't do a leakdown test, verify valve clearance, or non-clearance issue. No amount of governor fiddling will make up for low compression. And your description of problem is typical low compression issue. Not hard tests OR fix. Your in deep, finish it correctly. Test, Don't guess. 

GLuck, Jay


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## POSAriens (Feb 11, 2017)

Jay thanks. I don't intend to tweak the Gov as its been set per factory manual, my initial setting was wrong.

I'll borrow a good gauge to test though for sure as I'm also rebuilding an small outboard.

Thanks and I'll report back as I progress...


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## nwcove (Mar 2, 2015)

jmo.....save yourself some shoveling and repower it . a chonda will really wake that machine up.


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## UNDERTAKER (Dec 30, 2013)

*You just might have a dodgey gov on that engine.:tongue4::tongue4:*


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## POSAriens (Feb 11, 2017)

Update. Did a leak down test. Have not done this before but used a tester, was tricky getting to TDC, but when I thought it was there, I could hear and see the gauge show leakage. Assuming I did this right, that seems to be th problem.


I did try spraying some Seafoam in the valve area, not taking head off - saw this technique on YouTube. I taped the valve action here before using the Seafoam.

https://youtu.be/KY1c2mp6GOY

Seems to operate ok. there is some white colored stuff around rim of intake, not sure what that is.


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## cranman (Jan 23, 2016)

My rule of thumb on stuff I really need is to have two.....shoveling is not an option.. Two is one and one is none is a diddy my grandmother taught me. I sell blowers BTW.


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## 1132le (Feb 23, 2017)

POSAriens said:


> Update. Did a leak down test. Have not done this before but used a tester, was tricky getting to TDC, but when I thought it was there, I could hear and see the gauge show leakage. Assuming I did this right, that seems to be th problem.
> 
> 
> I did try spraying some Seafoam in the valve area, not taking head off - saw this technique on YouTube. I taped the valve action here before using the Seafoam.
> ...


5hp is not enough for heavy wet snow no matter how good the motor is


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## RedOctobyr (Mar 2, 2014)

Just seeing this thread for the first time. After messing with the governor, are you certain it's opening the throttle fully under a heavy load? Your video was good, it looked to me as though the throttle lever may be moving fully when it's in the snow, but it was tough for me to be sure. 

I'd check that, and also confirm by looking through the intake, to ensure the throttle plate really is fully open when the throttle lever is up against its stop. 

I did some fiddling with my Tecumseh governor a few years ago after realizing it wasn't opening the throttle all the way. I installed a new spring, which helped some. 

If you want to help rule-out governor issues, you could try a crude test. Like tying a piece of string to the throttle plate in such a way that you can pull it to open the throttle all the way. Then when you have it in heavy snow, and it's bogging, pull the string to ensure the throttle is fully open. If the engine suddenly pulls a lot harder, then the governor is not doing its job properly. 

You said the leakdown test showed issues. One point of a leakdown test is to see *where* the leakage is coming from, not just that air is escaping. If it's coming out the intake, the intake valve is leaking. If it's coming out the exhaust, the exhaust valve is leaking. If it's coming from the oil fill tube (after removing the dipstick), it's probably getting by the piston rings. And if it's coming from around the head, the head gasket may have failed. 

FWIW, my OHV OHSK100 Tecumseh showed about 30 psi when pull-starting, and 80 psi with the electric starter. This was after taking the head off and measuring the cylinder bore (in-spec, and still showed cross-hatching), replacing the head gasket, and setting the valve clearances. The only thing I didn't check closely was the valve seats (I was chasing a different problem, unrelated to valves). 

I'm operating under the assumption that my engine is functioning properly, yet it still didn't show a whole lot of compression when pulling it by hand. As was said, with the compression releases, it doesn't seem as clear-cut how much compression you should measure.


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## POSAriens (Feb 11, 2017)

Red thanks for taking the time for a detailed response. I'll double check the opening again. 

It seemed that I was getting air from the muffler, but I do need to double check that too, just need to get thru tomorrow's blizzard...


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## POSAriens (Feb 11, 2017)

Update: So after spraying seafoam into the valves thru the sparkplug hole a few days ago, to my surprise I was able to somewhat get thru the 5" of snow, not real wet snow but not powder. It bogged down but it took a bit longer to reach the point of almost stalling. 

I'll still check the butterfly to ensure its fully opening, but it seems fact seafoam may have done something to improve the situation, enough where I could finish a 100 foot driveway at the lowest speed...in the end my sense is valve job time over the summer...


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## ThumperACC (Mar 3, 2017)

POSAriens said:


> Update: So after spraying seafoam into the valves thru the sparkplug hole a few days ago, to my surprise I was able to somewhat get thru the 5" of snow, not real wet snow but not powder. It bogged down but it took a bit longer to reach the point of almost stalling.
> 
> I'll still check the butterfly to ensure its fully opening, but it seems fact seafoam may have done something to improve the situation, enough where I could finish a 100 foot driveway at the lowest speed...in the end my sense is valve job time over the summer...


Having watched your video, it seems like your governor is doing its job. You may indeed need a valve job but remember that 5HP is quite minimal for a 24" machine. The machine is effectively underpowered. You have to feed it at a rate that it can work effectively at. If that means with 5" of sticky wet snow you need to use 1st gear then that is what you have to do. Try to keep the machine moving at a pace where the governor is open but the machine is not bogging yet. Balance it out and you'll get the most out of your machine.

You can experiment with moving your drive disc closer to the center of the drive plate when in first gear. This will slow down first gear ( and all gears ) so that maybe in first gear you can do 10" without declutching.

Good luck,
Thumper


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## POSAriens (Feb 11, 2017)

*Problem Solved..i think*

Problem is solved. After taking off the head last nite, it was clear that the exhaust valve was never seating. 

Valve color looks strange...now off to lap the valve and seat and assemble everything together. I also removed the intake valve - might as well do a light lapping and clean so everything is in good order.


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## RedOctobyr (Mar 2, 2014)

I'm glad you found a cause! As for the weird color, it might be because the valve was getting extra hot, due to not fully-closing. Not closing prevents it from transferring heat to the valve seat, which helps cool the valve. 

Was your valve clearance too small, is that why the valve wasn't closing all the way? Or was something getting stuck?


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## drmerdp (Feb 9, 2014)

The valve wears deeper and deeper into the valve seat until there is zero lash, zero clearance. At that point the valve won't fully close allowing the rapidly expanding hot fiery gas to escape burning away the valve further.

Set your lash by filing or carefully grinding away a small amount of material from the valve stem. (Lapping is ineffective until you make the nessesary space for the valve to sit flush with the seat.)

Then lap until you have a uniform and even pattern on the sealing surface. Lap until all pitting is removed. Lapping will reduce valve clearance slightly.

Adjust the lash into spec by removing additional material from the valve stem as nessesary. 


Valve clearance for hssk50

Intake: .004"
Exhaust: .008"


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## POSAriens (Feb 11, 2017)

UPDATE: after completing the valve job, just purchased 2 new valves, lapping the valve seat, ground to spec, a complete cleaning and all new gaskets...the engine started on the first pull and I am now seeing 70+ psi on the compression (on the el cheapo HF compression gauge..) where before I barely got in the upper 30's.

Since it's not snowing today...I'm hopeful this thing is good to go.

Thanks all for input...


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## POSAriens (Feb 11, 2017)

Winter Update...after fixing the compression issue in the spring I finally had the chance to work the blower in 8-15" of snow...it ROCKS. No bogging down at all. Really throws the snow, even better than new it seems.. it seems to be idling higher than spec so will play with that in the summer..but for now it's working great. So it seems these Tecumseh engines do have this valve issue after all....


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## Shryp (Jan 1, 2011)

Yes, I have seen several reports of the exhaust valves on Tecumseh engines doing that. It is specifically the 5HP ones too. The lash gets too small and as they run the valves heat up and expand and then they no longer close fully. You need to take them apart and grind them down and lap them like you did.


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