90cc quad wont rev...what's your guess?

[wopachop]

Polaris 90cc 2stroke. 

Lent it out for a couple years. Motor wont crank. Throttle stuck.  

Opened carb and freed the slide. Might have been a dirty kill switch because the bike cranks over now.

Weird part is the bike idles awesome. Give it gas and doesnt rev. Pulled the air filter and squirting starting fluid with slide wide open and still the bike will not rev. It just kind of studders. 

Took the carb off. Cleaned it really good. Still will not rev. But idles great. 

Went to pull the plug and needed a smaller wrench to fit. Havnt checked it yet. 

Whats your opinion? Little quad idles great but will not rev using starting fluid with slide wide open. 

Hope its just a fouled plug. Really surprised idles so solid but cant rev up. 

 

[Kraut_n_Rice]

Does the slide move with the throttle lever?

 

[confyushus]

Make sure a brake or throttle switch isn't stuck on, I can't remember if they had those or not. Double check your jets/passageways in the carb, it's easy for something to fall in as it's reassembled, I've done that a lot. Also, something I ran in to on an e-ton which is about the same ATV, check the spark arrestor. Had a clogged one and would rev slowly with the rear off the ground but would not move if you sat on it, pulled it out and ran perfect.

 

[wopachop]

Yes i took the throttle apart when the slide was stuck. Im pulling on the throttle cable directly and the slide operates normal. 

Air filter is off i can see the slide wide open. Hit it with starting fluid and nada. 

Must be spark related?

Will take a short video around 10am.

 

[wopachop]

Ah spark arrestor. 

That could be it. We noticed smoke is exiting from the silencer down around the middle. It appears to have a bolt. Maybe a drain of some sort. I don't remember smoke exiting that spot before. 

 

[Sausage450r]

Coil or cdi. Check for moisture on stator. Spark should automatically advance with introduction of fuel (speed of flywheel determines spark output) 

 

[Bansh88]

Years ago my Banshee wouldn't rev.  Ended up being the parking brake having sand in it.  Bike thought parking brake was on.

Just a shot in the dark. 

 

[Realbadlarry]

sounds carb related...did you clean and blow out all the passages and replace the jets? 

 

[wopachop]

Make sure a brake or throttle switch isn't stuck on, 

Turned out to be a throttle switch. I always thought a safety switch would kill spark completely. Since the bike was idling i figured its not a bad safety switch. 

That was wrong. I was operating the throttle cable by hand. So the thumb throttle itself was not being moved. That meant the throttle safety switch was still pushed in. 

 

[confyushus]

Glad that's all it was! Had one that was the opposite one time, guy put the slide in backwards so it was wide open but the switch let it idle until you touched the throttle, 2 speeds-idle and wfo, haha.

 

[Time2Dune]

You beat me to it, I had the same issue on my daughters quad parking brake wouldn’t let it rev,  chased it for hours. 

 

[wopachop]

You beat me to it, I had the same issue on my daughters quad parking brake wouldn’t let it rev,  chased it for hours. 

Im going to test this bike. Curious if the engine will rev with the parking brake pulled in. 

There was a trip the kids were saying the bike seemed like it wouldnt rev at times. Wonder if the parking brake switch was bouncing around and acting up. I think we would stop, i would rev the bike stationary and show them its acting fine.

Get back on the ride and they would stall going up a simple hill. I thought it was just a kiddo rider having a bad day. Letting off the gas. I kind of didnt believe him that he was not letting off. 

Sure enough i bet it was a malfunctioning safefy!! No idea that form of child safety existed. 

 

[Sinverguenza]

Had a problem with one of my 90’s. It would idle fine and rev up but as soon as you would start riding it and it would bumpy, no go. Took of carb cleaned and still same thing. Long story short it was the spark plug wire.  The part that snaps onto to the spark plug was broken and barely hanging on. So when you start to ride and it would get bumpy it would not make a good connection. Just a thought.