Low Compression - Help

Forums / Repair

Low Compression - Help

Alex Yampolskiy /

Aug 13, 2019 02:10PM

So all of a sudden my Puch wouldn't start and after doing all the tests (fuel, spark, compression) I found out that it has very low compression and wouldn't turn over.

I replaced the piston rings and gaskets, however it didn't help and the compression is below 20psi. It did start once when I was pedaling really fast and "dropped" the clutch.

Am I missing something? Is it due for a full rebuild? When I replaced the rings, I did NOT hone the cylinder. Not sure if that's an issue as well.

Really appreciate any help.

Reply Quote

Re: Low Compression - Help

Stephen Simmons /

Go to branch

stephens

Aug 13, 2019 09:20PM

What kinda compression tester are you using?

Reply Quote

Re: Low Compression - Help

Aaron Blair /

aaronb

Aug 14, 2019 07:10AM

If it was still low after changing rings your comp tester is no bueno.

Did you try cleaning your carb?

Reply Quote

Re: Low Compression - Help

Mike Kirn /

mikehailwood

Aug 14, 2019 08:15AM

> Alex Yampolskiy Wrote:

> -------------------------------------------------------

> I found out that it has very low compression

> and wouldn't turn over.

> and the

> compression is below 20psi.

> When I replaced

> the rings, I did NOT hone the cylinder. Not sure if that's an issue as

> well.

>" Wouldn't turn over" means that the piston would not go up and down. Did you mean that the engine wouldn't fire?

Using the same compression tester, test compression on another machine to see if the tester is accurate.

Yes, not honing was a mistake.

> Really appreciate any help.

Reply Quote

Re: Low Compression - Help

Alex Yampolskiy /

alxmosly

Aug 14, 2019 10:16AM

Didn't try cleaning the carb, although it is probably due for one. The comp tester is from Amazon. I also tried covering the spark plug hole w/ my finger and the compression is still super low

Reply Quote