Kohler SV735 Rod Knock?

[Craftsman Garage]

What I have here is a Kohler Sv735 V-twin and at low idle it has a very loud knocking sound to it, very audible from behind the engine. Full throttle and it goes away a little bit but you can still hear it, just not as clearly. (I have had one of these engines before and for those asking "why another one???" Well, I guess I wanted to flip the coin again and see "how bad can it be this time?") I have changed the oil, filter, air filter, all the maintenance related stuff. I had a Briggs single years back with rod knock, but it wasn't as bad as this. Not sure if anything can fix this or if its even problematic?

 

[Bertrrr]

How many hrs on this machine ? If it's a Rod knock you'll need to go into it and verify and more importantly find out why , Was it not maintained properly or is the oil pump starting to fail, Don't think it's going away at higher rpms , maybe just not as easy to hear, Don't think there are rod bearings on this machine but one of these guys on this site will know.

 

[bertsmobile1]

Check the engine mounting bolts

 

[Tiger Small Engine]

Check the engine mounting bolts

I get several mowers a year with missing and loose engine mounting bolts. The Kohler Courage engine is also notorious with assisting in loosening the engine mounting bolts because it is not as balanced as it should be. Turn the engine off at wide open throttle and listen versus turning it off at idle as a sort of test for loose engine mounting bolts.

 

[Craftsman Garage]

How many hrs on this machine ? If it's a Rod knock you'll need to go into it and verify and more importantly find out why , Was it not maintained properly or is the oil pump starting to fail, Don't think it's going away at higher rpms , maybe just not as easy to hear, Don't think there are rod bearings on this machine but one of these guys on this site will know.

Only 350 hours on it.

 

[Craftsman Garage]

I get several mowers a year with missing and loose engine mounting bolts. The Kohler Courage engine is also notorious with assisting in loosening the engine mounting bolts because it is not as balanced as it should be. Turn the engine off at wide open throttle and listen versus turning it off at idle as a sort of test for loose engine mounting bolts.

That’s actually a good point, I had a courage single a while ago that had vibrated the bolts out to the point that there were none left I will check those bolts.

 

[Craftsman Garage]

Bolts were tight, like, really tight. Guess it’s something internal. I won’t worry about it.

 

[kbowley]

Bolts were tight, like, really tight. Guess it’s something internal. I won’t worry about it.

I would be concerned; a rod knock is a dreadful thing and not uncommon on the Kohler Courage.