I have a Troy-Bilt mower with a 17.5 HP B&S engine that broke a rod. I replaced all the internal engine parts and installed the engine back on the mower. I had difficulty getting the engine to run. Sometimes it ran for a few seconds, sometimes it would backfire through the carburetor. There was no consistency.
I found an identical mower on Craigslist with a locked rear end and good engine for a good price. I brought it in anticipation of just using the engine.
I decided to first compare the two side by side to see it I could find the problem. What I found was the key on the bad engine was sheared so the flywheel would not always be in the same position which explains my exact symptoms.
I replaced the key on the bad engine and it ran for about five seconds before the collar on the flywheel cracked. Since I had nothing to lose, I drilled 1/4" holes through the collar into the shaft and inserted roll pins. Again the engine ran for about five seconds and the roll pins broke. I even thought about welding the flywheel to the shaft.
I removed the flywheel from the good engine just to see how it would fit on the bad engine and did not see and differences. So I put it back on the good engine and used a new key because the old one looked worn. The new key was a little snug so I hammered it in. I installed the top bolt and started the engine. To my surprise, that flywheel cracked also.
Now I am at a total loss and need help.
I found an identical mower on Craigslist with a locked rear end and good engine for a good price. I brought it in anticipation of just using the engine.
I decided to first compare the two side by side to see it I could find the problem. What I found was the key on the bad engine was sheared so the flywheel would not always be in the same position which explains my exact symptoms.
I replaced the key on the bad engine and it ran for about five seconds before the collar on the flywheel cracked. Since I had nothing to lose, I drilled 1/4" holes through the collar into the shaft and inserted roll pins. Again the engine ran for about five seconds and the roll pins broke. I even thought about welding the flywheel to the shaft.
I removed the flywheel from the good engine just to see how it would fit on the bad engine and did not see and differences. So I put it back on the good engine and used a new key because the old one looked worn. The new key was a little snug so I hammered it in. I installed the top bolt and started the engine. To my surprise, that flywheel cracked also.
Now I am at a total loss and need help.
