GX240: Ran, disassembled, now it won't!

louky1150

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I am renovating a used and abused bed redefiner that came with a GX240. The entire machine, including the engine, was filthy. It had an oil leak at the bottom of the crankcase. I had to take the engine off anyway to do some welding on the frame, and decided to clean the carb while I was waiting for gaskets. The engine would start with a pull rope easily before I worked on it. NOW it won't start at all and in fact won't even pop with starter fluid. It feels normal when pulling, no noise, decent compression. I put an inline spark plug tester on it and showed a spark.

While changing the crankcase gasket out I ended up pulling the counterweight gear and shaft out, as well as the camshaft gear and shaft. I needed to do this to be able to fully clean the sump. I was very careful replacing these re. indexing the marks on both gears. I also took the valve poppets out and cleaned them and made sure they went back in the holes they came out of.

I'd appreciate any suggestions. I am thinking it is not anything to do with the oil safety switch since it does show a spark if the ignition switch is on. I feel like even if I had messed up the carb it seems like it would still at least pop with starter fluid. I do have a compression tester and will hook it up tomorrow; I am not sure what I should be reading since it does have a compression release. I guess it's also possible that the spark tester is showing a spark but I didn't actually test the plug by grounding it. Any ideas? Could something have moved in the valves that would cause this? I haven't had the valve cover off yet but will do that tomorrow also.

TIA!
 

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Fish

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A possibility is that when it went back together, the flywheel nut was not torqued enough and you have sheared the flywheel key.
 

Scrubcadet10

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louky1150

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Thanks for the replies and for the link. I did not have the flywheel off, and didn't remove the piston or crank. As I am new at this, if there was a problem with the woodruff key, I would still be showing spark (with a tester) but the spark wouldn't be occurring at the proper time?
 

Scrubcadet10

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As I am new at this, if there was a problem with the woodruff key, I would still be showing spark (with a tester) but the spark wouldn't be occurring at the proper time?
That is correct, you would have spark, just not at the correct time.
Of course, there aren't any rules that say a flywheel key can't shear when you pull the rope... only Murphy's Law...
 

louky1150

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Thanks! I will try to pull the flywheel today to examine.
 

louky1150

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I decided to take the valve cover off before pulling the flywheel, this is what I found. A combination of being happy and embarrassed both. Apparently when the lifters fell out when I had the camshaft out, the rocker arms shifted since I had turned the engine on it's side. I put these back and adjusted the valves. The engine started on the first pull and runs fine. I did a compression test after I got everything together and got 90psi. I want to thank those who responded to my question.
 

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AdamE

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I decided to take the valve cover off before pulling the flywheel, this is what I found. A combination of being happy and embarrassed both. Apparently when the lifters fell out when I had the camshaft out, the rocker arms shifted since I had turned the engine on it's side. I put these back and adjusted the valves. The engine started on the first pull and runs fine. I did a compression test after I got everything together and got 90psi. I want to thank those who responded to my question.
Glad it worked out! Things like this are such a great learning tool for idjits like me.
 
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