[jrentenaar]

i have a 2008 trx420fm rancher that i just replaced the gears and shift forks in the transmission,and after i put the motor back together it would not start. it just backfired the intake manifold off the cylinder.i cleaned out the fuel system,checked the timing ,adjusted the valves and changed the sparkplug.it still backfires the manifold off,i was wondering if anybody has had the camshaft automatic compression release stick?

 

[Helmut]

I don't think it would have anything to do with the cam decompressor system, because the decompressor holds the exhaust valve open and if it's blowing the intake manifold off, it sounds like the problem is with the intake valve instead of the exhaust valve. If it's in time correctly, maybe you have a bent intake valve.

 

[mud99]

Welcome to the forums.

 

[MNRedneck]

Welcome to the Forums!

 

[Helmut]

Welcome to the forums.

 

[shadetree]

welcome to the forums, sounds like you did what i did when i put my 2000 trx350tm rancher back together..go back in..and re-check your cam gear, i bet you don't have your right marks lined up on the cam and crank.

 

[JoeysDad]

welcome to the forums, sounds like you did what i did when i put my 2000 trx350tm rancher back together..go back in..and re-check your cam gear, i bet you don't have your right marks lined up on the cam and crank.

I agree Shadetree, sounds like its trying to fire with the intake valve still open.

 

[shadetree]

welcome to the forums, sounds like you did what i did when i put my 2000 trx350tm rancher back together..go back in..and re-check your cam gear, i bet you don't have your right marks lined up on the cam and crank.

I agree Shadetree, sounds like its trying to fire with the intake valve still open.

you are 100% right joeysdad, thats what happened to mine..lol.

 

[jrentenaar]

hi people thanks for your replie,but i answered my own question.i have rebuilt about 20 honda 420 rancher transmissions here where i live.but this is the first motor that i had to index the camshaft timing marks .i timed all the other engines with the cam mark at the top case mark,but this is the first cam that i had to disreguard the existing cam marks and index my own marks.i indexed my cam like this,i removed the camshaft off the engine and placed the cam on a flat surface with the cam lobes down lobes thouching the surface,then i used a speed square on the sproket side of the cam to make my mark at top dead center.i then installed the cam retimed with the new marks,piston at tdc,mag mark on the "t" reset the valve clearance ,and it ran perfectly.

 

[Jayp]

hi people thanks for your replie,but i answered my own question.i have rebuilt about 20 honda 420 rancher transmissions here where i live.but this is the first motor that i had to index the camshaft timing marks .i timed all the other engines with the cam mark at the top case mark,but this is the first cam that i had to disreguard the existing cam marks and index my own marks.i indexed my cam like this,i removed the camshaft off the engine and placed the cam on a flat surface with the cam lobes down lobes thouching the surface,then i used a speed square on the sproket side of the cam to make my mark at top dead center.i then installed the cam retimed with the new marks,piston at tdc,mag mark on the "t" reset the valve clearance ,and it ran perfectly.

hi people thanks for your replie,but i answered my own question.i have rebuilt about 20 honda 420 rancher transmissions here where i live.but this is the first motor that i had to index the camshaft timing marks .i timed all the other engines with the cam mark at the top case mark,but this is the first cam that i had to disreguard the existing cam marks and index my own marks.i indexed my cam like this,i removed the camshaft off the engine and placed the cam on a flat surface with the cam lobes down lobes thouching the surface,then i used a speed square on the sproket side of the cam to make my mark at top dead center.i then installed the cam retimed with the new marks,piston at tdc,mag mark on the "t" reset the valve clearance ,and it ran perfectly.

I’m having same exact problem can u give me more info on how to do this