KT Compression
 

I am working on a KT-17 II and doing a Compression Check. The Service Manual states a minimum of 90 PSIG.

I was wonder what is considered "normal or typical".

:bigthink:

Normal and typical, I've not seen much more than that unless freshly bored/rings and broke in.
They have a low compression ratio, so low pressures are expected.
Also gauges vary. Can't say I've seen much over #95
FWIW:
John Deere specks different cyl. heads with a larger volume in the heads.
so a little less compression ratio but not much.
:BlahBlah:

The reason I asked, I thought I read somewhere, that 110-115 area was the norm. But that is what I recall. And these days, I just don't know for sure. :bigeyes:

I’ve always been taught that at least 100 psi is needed. 95 seems low, but if that’s what the manual says??

Per Kohler, minimum of 90psig, and no more than 15% variation between cylinders.

One has to remember the compression ratio is 6 to 1
About the same as the old ford flathead engines of 75 years ago.

A lot of todays Gasoline engines are about 9 to 1
and diesel compression ratios are about 22 to 1.
So that accounts for the lower pressures in the KT series.
They can run low octane fuel and not overheat and not suffer "spark knock":beerchug: