Engine won't start after camshaft replacement
I had a mower that had a compression release spring problem on the camshaft detailed in the following fixit question:
I had the mower running for a whole season but it got worse so I decided to strip it down and indeed the compression release spring was in pieces inside the engine case. I installed a new camshaft (changed out the oil gov and all seals rebuilt the engine and it started up first time with no compression or turnover issues at all. See Below:
I then left it for about a month, went back and it started again first time. I let it run for a while and all was good. Then the next time I came to start it I forgot to turn the fuel cut off valve on and so it ran out of gas and stalled after a minute. I turned the valve on, and got it started but then it began to run rough and now won't start at all. I thought it was still fuel starvation but checked the carb and was letting fuel through fine. Checked the spark plug and it works fine - did smell heavily of gas when i removed it. See vids below - any thoughts? Has the timing gone?
I stripped down the carb, all looks good. Spark plug working good and valve spacing is all good. Here is another video of it trying to start and the good spark plug.
I stripped down the cylinder head - lots of carbon build up. Cleaned that out and piston head, replaced head gasket, checked valve spacing, stripped carb again, checked bulb solenoid, replaced spark plug and checked it is firing from the coil when out of engine, replaced with fresh gas and.....still no luck:
I’m lost for ideas unless something has failed inside the case somehow, but can’t think what....