Small Engine Problems? Ask an Engine Mechanic for Answers ASAP
Can be difficult, but what you need to do is place the engine at top dead center (piston at the very top, crankpin journal pointing straight up) and then the cam gear will have 2 marks that line up evenly on each side with the valve cover gasket surface or cam bearing surfaces - - 2 marks 180 degrees apart and one mark pointing straight up, and crankshaft at top dead center, you should have the valve timing just about dead on.
What do you think made the belt come off and do you think it should be replaced. This is in cold weather use - logsplitter?
Hmm so the belt came off by itself?
it should not - there is no adjustment - if it came off by itself it is either broken or damaged and you have to split the crankcase to get a new belt installed as it fits over the crankshaft
it should not come off in normal operation, unless or until it breaks or cog teeth strip off
If the belt teeth or cogs are ok, do you think the belt should be replaced. The cam gear has no signs of wear.
the cam bearings are OK? if the belt came off by itself, it should be replaced
you may have a problem with camshaft bearings, crankshaft main bearings, possibly, - does the camshaft turn freely ?
if the cam is binding you may find stripped cogs somewhere on the belt, but in any case if it came off by itself, whatever the cause, it should be replaced, and the cause corrected.
I have a snowblower engine sitting on the bench with a camshaft gear spun on the shaft caused by water getting into the engine and hydro locking the engine.
This is a plastic gear on a shaft, it appears to have no wear or play for the gear to allow the cam gear to wobble and the crankshaft is tight in the housing. I did not pull the bottom to check, but I am assuming that the crankshaft gear is metal.
yes it is
plastic gear can spin on the metal shaft - what I am meaning is if the camshaft will turn freely - you should be able to turn it freely and work the valves (do not spin the engine until valves are in time though)
the cam shaft can bind in the cam bearing caps if there is a lubrication issue or warped head or alignment issue
but if that bound up, the crank will shear belt teeth off the belt and belt stops turning , gets loose, and likely can come off
if it came off by itself, I am assuming you took it apart to see why engine quit - but if it fell off by itself, it's definitely going to be necessary to replace the belt
Thank you. You were a very big help.