I have a 88 Suzuki 300 Quadrunner. It runs great and starts easy. Recently, after riding for about five minutes, it wants to stall out. If I try to start it immediately, it will hit but not stay running. i can let it sit for a couple minutes and it will start up and stay running but stall out again. What can be causing this? Any known problems? What should I check? Any help at all would be appreciated!

 

I rode the four wheeler today until it started to stall. Right away, I checked for spark, which it had, and pulled the gas line and turned the engine over. It had gas coming out. I have spark and gas flow where do I go from here? Anything else I can check? Any help on this would be great.
Almost forgot, it will start after it stalls but runs bad. It will miss and backfire and eventually stall out again.

 

Maybe clean the carb (plugged jet)?
Valve adjustment?
Plugged pipe?
Even tho you seen fuel flow, I'd make sure the gas cap vent is not plugged.
Hope some of that helps.

 

I talked with a guy who works on four wheelers about this problem. he said it sounds like the voltage regulator is bad. I checked the voltage across the battery while running and was getting around 16 volts and as high as 17 volts when giving throttle. that voltage sounds a little high, but can a voltage regulator cause the bike to stall and run bad after warming up?

 

Yep, it should never be higher then 14 or 15volts. and that's when the battery is asking for juice to recharge. Too much voltage will cause the coil for the sparkplug to over load and miss fire.
Try this, while riding along give it full throttle and when it starts to missing turn the lights on and if it starts running good again that's your clue it's the recticier.
It's not a cheap part either, I paid $136 with shipping on my last one.

 

Just getting back to this quad. I am sure the voltage regulator was bad, so I got a new one. Now my voltage doesn't go over 15. Thought for sure my problem was fixed, but after test riding, it stalled again! I have already cleaned the carb and now a new voltage regulator. I'm running out of ideas and need some advice on what to check. Thought about taking an old gas tank and bypassing the fuel pump to see if that may be the problem. Anyone got any other ideas? Heard maybe the cdi box, but not sure if there is a way to check it.

 

An remote would be an great ideal to see if your atv will run normal that way! sounds like you may have an ethanol in fuel [bad fuel]. But try the remote tank first an lets go from there! Keep us updated.....We have alot of problem here with ethanol. fuel can be coming out of line BUT the temp is to high in fuel the inside the carb it would act like an vapor lock! Put the remote tank higher than carb an let the garvity flow to carb an try that!

 

How long can you ride it before it starts to stall or dies ?

To me, this sounds like a carb / intake / fuel pump issue. Keep in mind, the fuel pump is vaccum fed also. What I am saying is check your compression too. If your compression is below 100 psi. could be issue too.

But ya might just have some junk in the tank, floating around too, thats bouncing and after a bit is partially or blocking the whole / fuel line to the pump or a weak fuel pump.

look fro cracks or poor seating at the intake also, if it warms up, it might expand or cause just enough bigger whole or gap to cause it to loose proper suction of air / fuel.