How low is compression on your tractor?

[country 0]

My 917H has been dealing me a fit once in a while. It will running fine, and out of no where, just start missing and sputtering, and eventually die. Sometimes I'll have to let it sit for a while to cool down before it will restart. I began to look into it last night, and the first thing I did was measure compression in the Kohler KT17 series I. One cylinder had 75psi, the other 80psi. This is well below the 90psi recommended in my Kohler owners manual. So, the 23 year old original beast needs some freshening up, eventually. How much longer can I expect it to run well enough to keep mowing?

[HubbardRA 19]

Before you go too far toward rebuilding, I think you should check the valve clearance. Valves have the tendency to beat themselves into the seat and actually reduce the clearance over time. If you don't have enough valve clearance, especially on the exhaust valve, the valve will cease to fully close whenever the engine heats up to a certain temperature. Just to be sure, check the valve clearance before you make the decision to rebuild.

[maxtorman1234 0]

In addition to valves, missing and sputtering is also caused by bad ignition coils, possibly feul, and as i have found out bad condencer will do it also.

[toad270 15]

what should my compression be on my 9hp briggs

[Ronald Hribar 91]

I've has similiar problems. First time fuel pump was culprit, second time it was not charging properly due to ignition switch connections, Took care of connections and charged battery and it ran like a BRIGGS

[D-17_Dave 12]

Sounds like a condenser problem.

[BLT 717]

Briggs doesn't publish a compression standard, but 85-90 PSI will get you by.

[toad270 15]

thanks BLT

[Woodydel 0]

Check head bolts for looseness. Hold throttle full open during compression test. You need air to compress. Do a dry test of the compression. Do a "wet" test of the compression to check for bad rings. If everything stays the same suspect the valves.

[MikeES 454]

I have run the old cast iron Briggs down to 60psi but barely. Below that you can't get them to rev up.

[Salthart 0]

Next oil change, either go with a thicker oil or add "Motor Honey" to the oil you use. Run it a while and like said above run the comp test with the throttle open. If you see a large increase in compression, you can figure its time for an overhaul. But with most engines, Your oil rings go before compression is a problem, My bet is with the others,, A valve job. Good luck. P.S. I'd bet if you shut it down when next you get that miss, and remove the float bowl, you'll find water. Most of the time it will lay in the low spot and cause no trouble. But every so often you hit a bump or more water comes in from the tank and there's your miss..