The "I'm Obsessive With Lawn Tractors" Thread

Tomeal said:

joesregalproject

I ordered the parts to put it back together. When the rockers go back on is there anything special to it? Torque spec or lash setting?

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Tomeal said:

I will ask here.

View attachment 255783

The top rocker is loose and flopping around, the bottom is still tight but off the valve.

Any ideas on the root cause. Havent had to tear any small engines down.

What do the rods ride on? Is there some kind of a cam shaft in there?

Im going to research more, just figured someone here can point me in the right direction faster than me researching it, tearing it completely apart just to find out the engine is junk.

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Wageslave said:

I had a Briggs AVS engine that would eat an exhaust pushrod every few months towards the end of it's life. It would either throw the rocker arm and have a bent pushrod or the last inch or so would be rubbed through by the guide and the pushrod would break.

My working theory was that the exhaust valve was getting tight in the guide when it really got worked and would bend the pushrod enough that it would rub the guide and eventually rub through the side of the pushrod and it would come apart and shut down the engine. The shiny spot in your pushrod suggests that something similar may be happening to you. You can just swap a new one in, reset your rockers, and go but it will be more than likely happen again. A new set of valve guides would probably be the long term fix.

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Tomeal said:

I'm getting a used head for the other motor. The head off that one has chips in it. This used one im getting I'm thinking of rebuilding it new parts so maybe i can avoid that.

I can rebuild the used head to swap with the other one when it fails.

For now i may throw the parts in the newer motor to get it running and see how long it lasts.

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