# Tecumseh LEV120



## RKDOC (Jun 20, 2006)

This engine has 50 lbs of compression. Is this enough to make it run right? The customer complaint is hard starting. Thanks for any insight.


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## Restrorob (Dec 23, 2007)

I have never gotten one to run right with only 50 lbs, In fact a few wouldn't start at all.


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## RKDOC (Jun 20, 2006)

Thanks Restrorob. I have got this to fire on carb cleaner, but won't keep running. I took the carb apart and cleaned it with no help. I will do a leakdown test and see if I can tell why the low compression. Thanks for the help.


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## RKDOC (Jun 20, 2006)

I did a leakdown test on this engine. It shows less than 5% leakdown. What things would cause the engine to have low compression and yet have no leakdown? I checked the valve lash, it is fine. Took the head off and checked the valves, they look fine. Replaced the head gasket. Still only have 50 lbs of compression. Any suggestions will be greatly appreciated.


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## 30yearTech (Sep 14, 2006)

Low compression reading may be due to compression release.


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## jsouth (Jan 31, 2008)

Do this squirt a teaspoon oil in the cylinder,check the compression again,if the compression goes up then the rings are bad,if no change need to do a valve job.

Jerry


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## Restrorob (Dec 23, 2007)

30yT,

Even with a compression release wouldn't you think it would need over 50 lbs ?

I mean, I have used my compression tester on many engines with C.R just to see if I had ample start-up compression. I have seen anywhere from 30 to 120 lbs. but with 50 or less being non/hard starters.




RKDOC said:


> What things would cause the engine to have low compression and yet have no leakdown?


Two possible things come to mind, While you had the head off did you try to wiggle the valves (while open) up and down in the guides ? A worn guide could let the valve seat while sitting still but rock on the seat while cranking/running.

It's possible the cam lobe(s) are worn preventing the valves from opening far enough.


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## 30yearTech (Sep 14, 2006)

Restrorob said:


> 30yT,
> 
> Even with a compression release wouldn't you think it would need over 50 lbs ?


 Need or Read??

Yea, it was just a thought. I never really have any problem getting good readings on units with a compression release. I don't know how many times he is pulling it to get this reading, if it's only one then it's a pretty good reading.


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## Restrorob (Dec 23, 2007)

30yearTech said:


> Need or Read??


Well,

Either need over 50 or should read over 50 


Your right about the times pulled, We also don't know if he had the throttle set at wide open position while testing as well.


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## RKDOC (Jun 20, 2006)

Thanks for the replies. I pulled the rope 3 or 4 times to check the compression. Yes the throttle was wide open.

Did I understand right, that one pull is better than several when checking the compression?

Thanks for the help. You all are the best.

Is this a Tecumseh thing (low compression) I had two more today with the same thing.


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## 30yearTech (Sep 14, 2006)

RKDOC said:


> Did I understand right, that one pull is better than several when checking the compression?


No, pull it or crank it (electric start) until the guage stops building up compression, usually a few pulls or a few seconds of cranking.


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