Nor7

Sounds like the same problem I had. It ended up being the intake valve was out of adjustment. In fact it wasn't moving at all. I put some play into it and it fired right up.

Look at the repair manual. I believe model years '90 through '98 were identical/interchangeable.

Yep!! That did the trick. There was no play in the intake valve. I wasn't able to get the feeler gauge in there due to a bunch of stuff in the way. I was able to adjust it though and then she ROARED to life!!! Problem though, my brother said to put some oil in the top end. Didn't seem right to me but I did and I think its dumping oil into the exhaust. Its smoking like crazy. I would have thought the top end would take oil from the system. So question: Should I drain any remaining oil from the top end and just put a little in or leave it without oil or what? I read the repair manual and it didn't say anything about oil capacity in the top end. Thanks in advance for any helpful info. Oh, and I tried to remove the exhaust to flush out any oil in there but due to abuse from previous owners, I was not able to get to it without some major quad surgery. I guess Ill have to wait for it to burn out.

Ok, I think I have narrowed down the problem. I replaced the spark plug, tried to crank it a few times, then removed the spark plug for inspection. It did smell like gasoline but it was bone dry. I think my intake valve is clogged or something. I am pretty sure I am going to have to take the top end off and clean the valves. Any suggestions for what else I should do while I am in there?

Ok, so I just bought an early 90's QuadRunner. My brother and I tore the carb apart last night and cleaned it out. I mean we went all the way, cleaned out the jets, cleaned the bowl, all that good stuff. We confirmed the spark plug was good, we saw gas jetting into the carb when we tried to crank it. The engine sounds like it wants to turn over, it just doesn't. ????Similar problems????

I just wanted to say hi and introduce myself. You'll probably be hearing alot more from me since I just bought my first ATV and I'll be hitting everyone up for advice and what not. Oh, and the model is either a late 80's or early 90's QuadRunner 250.