[devon2576]

Okay so my fourwheeler was previously worked on by someone i was referred to but did not do a good job. everything looks good except the timing. It would start and run but back fire real bad and die if i gave it a lot of throttle. when i took the valve cover off i set the cam gear to proper timing position (two horizontal hash marks parallel with head and dot facing up) then i removed the inspection hole screw on the cover and the he had it lined up with the mark for the spark advance (the left one of the two vertical marks). I figured that has to be my problem. Correct me if im wrong on that. Now my problem is i can get it perfectly aligned with the TDC mark on the flywheel and the cam gear marks but when i put the chain tensioner in it gets off a little. the chain isnt stretched because with the tensioner fully extended it sticks off the motor. can someone outline the steps after aligning the flywheel and cam gear to do so without messing up the timing.

thanks

 

[devon2576]

Your never going to get it absolutely perfect. a lot of times you'll think your about 1/2 a tooth off when in reality your dead on, its just the way it looks once the tensioner is tight.

get your timing mark lined up in the inspection hole, then line your horizontal marks up on the cylinder head deck. install the cam tensioner and be done with it.

your thinking too in depth on it.

I had thought the same thing as a possibility. i have just read a lot and seen videos that emphasize the need for accuracy. Ill get it back together this evening and chime in with the results.

Thanks!

 

[devon2576]

when you have it lined up on the timing marks - are the cam lobes facing down and there is no pressure on the rocker arms ?

Yes and yes!

 

[devon2576]

what kind of work did the guy do to the engine -----what was the reason for having it worked on to start with

I had the top end replaced. new piston, cylinder, and valves. The gaskets and RTV all look good. I checked the valve clearance with a feeler gauge and it is good. I just noticed the timing marks were set to the wrong mark after digging in myself because it ran like crap. Looking back now i should have rebuilt it myself but i was busy that week working on my truck and working full time. next time im doing it myself for sure

 

[devon2576]

So after re timimg to the correct mark it runs much better. Actually can rev it without it completely bogging out. now i just need to tune the carb! if anyones got tips please chime in. I know its roughly 2 1/2 turns out on the mixture screw from lightly seated but thats about all i know haha

 

[devon2576]

Was it stock rebuild, or oversized??

Has the carb been cleaned?

stock rebuild, and the carb is brand new but the mixture screw is out of whack because of how much i tinkered with it in the first place thinking it was the carb before i discovered the timing