Hello, I have a 17.5 hp kohler cv491s on a 2004 deere riding mower. At 40 hours the engine through a rod. I disassembled the engine, the crank was okay so I polished up a little. I replaced the broken connecting rod and reassembled. I am 99% sure of the timing mark alignments on the small gear and the large gear. After reinstalling I found the carb to be gummed up from sitting a little over a year. Fuel pump is fine so I cleaned the needle and seat etc. and the fuel shut off solenoid seems to be working-it clicks when plug and unplug with the key on. Now backfires through the carb all the time and will not run. Is there anything that could cause this other than the timing being off?

Hi,
I would say you did not get the flywheel tight enough and you sheared the key. Barring that you will be going back in to check those timing marks.
Backfire through the carb can only mean the ignition is arriving with the intake valve open.
Peace,
Clarke

Thank you crigby. I did not remove the flywheel and never gave a thought to the key shearing when the rod broke. Thanks again.

I did the same you did on my 17.5 kohler .in my case the cam wore out a lobe good thing I had an extra.now works perfect.