New to forum, great place I hope someone can steer me in the right direction. I have a craftsman rider with a kohler cv15 s engine. I think the valve lifters are sticking. After startup, the motor hammers loudly. Sometimes the hammering goes away and the thing runs fine. If I shut it down, and restart the hammering starts up again. I took the top end off, no broken valve springs, no bent pushrods, no damaged parts. I changed form synthetic to nonsynthetic this spring and the problem started up about a couple of hours later. I think it is a coincidence. Anyway, I changed back to mobile 1 10w30 and still have the same problem.
Is it hard to change the lifters out, or should I bring her to the shop. I miss my tractor.

 

No they are not hard to replace, go to www.kohlerplus.com
you can download a service manual for your engine there.

You have to use internet explorer to access the site, but you can log on as a guest and look up part numbers as well as service information there.

 

It does sound like the lifters aren't pumping up fully. I've heard this on a couple of kohlers, but the customers never wanted to fix it, so I have not verified that the sound is caused by that but I think it is.

They're easy to change. Let us know how it works out.