Just got a 95 yamaha wolverine 350 4x4 and it wont start cranks multiple times just no start i pulled the plug and it got great spark and compression so i put starting fluid in and still nothing so i held the throttle down and it pops and shoots a flame back through the intake i thought about everything please help

 

Inspect your carb boot and clean your carb

 

I cleaned thw carb checked the jets ans gapped thw plug if it helps when I pulled the old plug out it was touching and no gap

 

Only three reasons for the plug to have no gap, Wrong plug, i,e, too long and hitting piston. Or previous owner tried to get bike to start by knocking gap right down. Or something dropped into inlet manifold or plug hole, which then jammed between piston and plug. Had that on a Suzuki 450 recently.

 

What would be your guess as to the problem to all of this

 

It was also the right plug for it

 

OK, lets assume the previous owner knocked the gap down. Are you sure it has good compression? A test would ensure it isn't that. Flames from intake tend to indicate timing out, but double check that manifold like Jered651 told you. If that, and compression are OK, check ignition timing. Spark plug out, light down plug hole, watch for piston rising to TDC, when it gets there remove plug from timing hole on flywheel cover and check that T mark agrees with piston. If that is OK, check valve timing, T mark should agree with mark(s) on cam sprocket when you take the side cover off the cylinder head, can show 180 degrees out on some models, but that is OK, as they will agree once you turn the crank one full turn.

 

How do I adjust for ignition timing?

 

There is a black plug on the left side of the motor pull that plug and line up the T with the little tab on the case. Next take of your time chain cover on the head if the line on the sprocket lines up with the tab on the head you are in time If not rotate the crank another 180 degrees and check it all again.

 

Ill give it a shot and let ya know thanks again guys!