Small Engines (Lawn Mowers, etc.): ch20 bending pushrods

Question
hello i have a kohler ch20 that i just overhauled. on first startup we gave it ether. it instantly bent all 4 pushrods. we have checked cam timing and made sure the valves were not hitting the pistons. we straightened the pushrods and put them back in. it had compression until we gave it ether. it bent the pushrods again. we tried to start it without ether but it still bent them. ideas would be appreciated. thanks

Answer
If they bent once then they will bend again as they are weak.  I've read several articles where folks said using ether can damage today's OHV small engines.  I just use regular gas for priming engines.

You will need to replace all 4 push rods.  Some engines have specific push rods for intake and exhaust valves.

I would check the mechanical timing, cam shaft alignment marks, and verify the flywheel key is not sheared.

Did you download the engine service manual from Kohler's website?

Eric