I was out riding some trail at a lake last weekend. Raptor ran fine for the first few hours then it started cutting out climbing some hills. It actually died going up a 50' or so hill. When it first started doing it I thought it was loading up and after I got up the hill I would rev it a little and it cleaned up and ran fine till the next hill climb. Then the same thing. On the flats it ran fine though.

I thought maybe a float level was too high or something but I noticed a little gas coming out of the vent hose and around the gas cap. Like there was pressure in the tank. I took the vent check all apart tonight, figuring there was something plugging it up. It all looked fine and clean. I can't find a diagram of the check assembly to make sure it is together correctly and that no parts are missing. It looks right but I don't know. I have only owned this quad for a couple months so who knows if it has been apart or what. It was defenantly loaded up becasue when I got it fired up again after it died on the one hill it puffed a bunch of black smoke.

When I started riding the tank was full and when it started having problems it was half or so. After this problem I just called it a day so I really didn't try anything while we were riding.

Anyone ever run into this problem?

Thanks

 

It sounds like the float level. It only takes a few minutes to check using a piece of 1/8 inch clear tubing.

 

I checked the float levels and both were right at the head of the screws that holds the bowls on. Which I would guess is right at the 4mm. Should I lower them a little or is that good?

 

How I check float level. Remove stock hose from bottom of carb, attach a clear tube, hold open end up next to carb with opening higher than carb, open drian screw, fuel will fill the tube and show you level of fuel in carb. Show show level with or slightly above seal on carb.

Another thing to consider - Was it only cutting out when climbing long hills and were you running full throttle? Does it also cut out if you accellerate at full throttle for a long period? You'll see this kind of behavior if your engine is consuming more fuel than it can get from you gas tank. Could be blockage - or it could be as simple as not turning the fuel valve on all the way...

 

I had almost the same thing happen to me today except I was riding a YFZ up steep hill in second gear I had the rpms about half way up and it died right as I got to over the hill. Im glad it didnt die as I was going up the hill or I would have been screwed up real good. I dont know if it would be the same problem with float level on my YFZ or not. Im not much of a mechianic and gust got the bike two days ago so Im sorry to say I cant really help you guys out.

YFZ-450 stock

Suzuki Vinson 500

 

It would only do it going up steep long hills. These trails are faily tight and getting it wide open for very long is tough, but I never had it cut out when I could run it through a couple gears hard on the flats.

I took the carbs off the other day and set the floats to what the service manual said. 13mm (.510") from the upper bowl face to the bottom of the float. Mine were a little high at .300". I am going to ride it tomorrow so we will see. Problem is that it is a pasture we are riding in, no good long hills. just short ditch type stuff. It really will not be like what we were riding last week.

Also I opened the fuel valve when I had the tank off and it flowed fine. Forgot to check the hose though.