My girlfriend's son, inherited an '88 250 quadrunner,that isn't running very well. Very difficult to start and will only idle occasionally and runs crappy at higher rpm's.
He put a carb. kit in it ,since the float needle was wore out.
I looked at it last night and was going to help him adjust the valves but could not find a peep hole to verify top dead center. Does this model have an inspection cover hole that i missed or shoould i just go by the cam??

 

Just take the spark plug out and use a screwdriver to find TDC. Some of these engines don't have a peep hole. Even if they do, its still hard to nail TDC exactly due to the magneto wanting to move the crank. Its not that critical anyway. A screwdriver works fine.

 

straight or phillips. I found it. thanks

 

I like philips.. large diameter too. Less likely to scratch anything inside leaving a hot spot for pre-ignition.