K321 just died.

[nutzboutoldies]

I was mowing tonight with the 1450, all was going well until the K321 backfired and died. Now the engine cranks with no compression, kind of like when a timing belt breaks in a car. Could this be something as simple as a flywheel key or am I looking at pulling the engine to investigate something with the cam?

[Matt G.]

I'd see if the piston is still moving first...sounds like it threw the rod.

[nutzboutoldies]

Thanks for your reply Matt. As I'm sure you know, I was hoping for somethig a little simpler. I rebuilt this engine this winter, new rod, piston etc. I'll pull the plug and verify if the piston is moving and go from there. I'll keep you posted.

Steve..........

[nutzboutoldies]

I took the head off and verified if the piston was moving up and down. It was, however, what I found was a broken exhaust valve. I had rebuilt this engine last January and have only put less than 20 hours on it. You guy's have any idea's if this is just could possibly be a defective valve or could there be something else going on? First picture is what I saw when I first removed the head and the second is of the broken valve.

[Matt G.]

New valve or was it original? If new, OEM or aftermarket? Can you show us a clear close-up of the break?

[nutzboutoldies]

Originally Posted by Matt G.

New valve or was it original? If new, OEM or aftermarket? Can you show us a clear close-up of the break?

Matt, both valves were new and purchased from a local auto parts store, I'm pretty sure they were not OEM. The part numbers on the invoice are not Kohler numbers. These pictures are of the exhaust valve. The intake appears to be OK except when looking at both of the valve faces they have already begun to "grove", not sure if that's the right way to describe it but you should be able to see it in the pictures.

[Matt G.]

I have not seen something like that happen before, but that appears to have had a pre-existing crack in it that grew until it broke. Kohler valves aren't cheap, but I think I'd get some if I were you.

[nutzboutoldies]

I just checked on the prices for Kohler valves, you're correct, they're not cheep. I guess the time to replace the valves ought to be worth something, not to mention any other damage that could arise when a valve breaks. Might make the extra cost worth while. When replacing the valves should I just replace or will lapping be necessary? As I stated earlier the engine was just recently rebuilt and the seats were ground at that time.

[Matt G.]

You'll still have to lap the new valves.

[jeff967]

my money is on that valve was dropped on the shops floor they do not like that