valve adjustment

[ACF]

have a briggs aand stratton engine model 31g777-0290-e1, would not start all basic there new carb, electrical ok. pulled valve cover found that intake push end was broken at rocker arm, replaced. went to adjust valves set engine to tdc set at .005 turned engine by and to recheck clearance there was no clearance so reset and turned over by hand this time there was an excessive clearance. repeated this several times and got same results going from to tight or to loose. looking for any clues as why this happens and to resolve the issue
thanks

 

[StarTech]

Just turn engine until the exhaust valve is fully open and then set the intake to .004 +- .001. I prefer to set to .003 since OHV valve clearances tend to open up over time.

IF set by Briggs instructions it is done with the piston 1/4" down pass TDC compression stroke. This is so the ACR does not affect the adjustment.

 

[ACF]

question when i rotate engine the intake spring goes pass the edge of the cylinder head was the exhaust moves but a couple runs of spring extend pass the edge of cylinder head, does this indicate that i have valve stem guide has come out of the cylinder head

thanks

 

[StarTech]

question when i rotate engine the intake spring goes pass the edge of the cylinder head was the exhaust moves but a couple runs of spring extend pass the edge of cylinder head, does this indicate that i have valve stem guide has come out of the cylinder head

thanks

Going have to clarify this as what is posted does not make sense to me. Especially with my migraine

Both rockers should move the same amount. Also make you didn't loosen one of the studs.

 

[ACF]

spring compression studs tight exhaust dose not move as far as intake, looked at push rod not bent, could the lobe on the camshaft be worn thus not allowing exhaust valve spring to compress as much as intake valve

 

[StarTech]

Yes. I have replace cam that worn so much that engine barely ran with back firing out of the carburetor. Also replaced several others that were worn although not as much.

 

[slomo]

Going to have to defer this to my CSI buddies.

 

[ACF]

engine clean and it does back fire via carb when i started after valve clearance

 

[ACF]

thanks for help found 2 problems one was compression spring broke and the camshaft lobe was worn down
thanks for all the help

 

[Tiger Small Engine]

thanks for help found 2 problems one was compression spring broke and the camshaft lobe was worn down
thanks for all the help

So you removed engine, took the sump cover off, and determined that the camshaft lobes were worn. How did you determine this, visually? Not saying you are not correct, just asking. Also, what compression spring? Do you mean the valve spring?