See if those marks line up first, if they do and the T mark agrees with piston TDC, my long distance diagnosis of "timing out" was wrong. Changing a cam chain on a Yam 350 is a swine of a job, timing the harmonic balancer afterwards is very difficult compared to timing the cam, and you are having problems checking that. The chain doesn't look slack on the picture so probably won't need changing, but only someone working on the engine could say for sure.

 

Thanks for all the help so far man, i only know basic mechanics, i’m a carpenter by trade never seen inside a engine, so it’s all new to me. I checked spark on the new plug and it’s good, checked compression and it’s at 154. The sprocket looks to be a tooth off after i rotated the crank one turn. let me know if you have any other ideas. Much appreciated 👊🏽
any way to check valves if bent? also will a car battery charger work with the atv so i don’t have to keep using the noco booster? could i have gotten a faulty carb?

 

I would say half a tooth, so you are going to get it half a tooth out the other way if you try to change it, this is not enough to affect performance. It should run with that compression so, be sure you have a good spark and plug, clean the carb out and try again. You don't have a bent valve with over 150psi compression.

 

These engines have alot of starter clutch noise when they get worn

 

Yes, I was wondering if it is slipping, particularly with that amount of compression, it gives a rather similar noise to timing out, as slowing just before firing makes the spark seem over advanced.

 

Charged up battery to 100% and still not starting. Spark plug is NGK DR8EA. Starter clutch job doesn’t look too bad. Will this one of amazon work?

 

May need a flywheel puller also

 

finally got around to pulling the flywheel and it looks good also only turns counterclockwise so the one way baring is good too. Can’t get the flywheel separated form the rest. the 5mm allen key bolts took everything my impact had. any tips? also is it worth replacing if everything looks good?

 

Can use a impact driving[twist type] iimpact to remove or use a little heat to melt the loctite,yes I would since you there sometimes manual turning on starter clutch inspection isnt enough power to force slipping like an engine can do IMO I would also use loctite when reinstalling allen bolts

 

Be very careful if using heat, the flywheel magnets will be glued on and heat can degrade the glue, which is what you are wanting on the one way clutch threads.

I have just fitted a new stator to a 400 King Quad and notice it has started to sound like that when starting. I think the new trigger coil may be a bit off, you can't alter the positioning, but I was wondering if the factory got the trigger wires the wrong way round. Have heard that this throws ignition timing out.