My dad and I each bought a 2005 raptor 660, about 9 months ago, and they both ran fine until about a month ago, my dads quad wouldnt start, it was still under warrenty so we took it down to the yamaha dealership, and it just had bad gas in the carb, that was a quick fix. He took it out for a couple rides right after we fixed it, and it ran completely fine. Then my dad let it sit for about 2 weeks and today we went to start it and it started fine, but it wont idle with the choke off, and when you give it gas when the choke is off, it sounds like it is backfiring. Im sure it has somthing to do with just sitting for 2 weeks.. Maybe it will be fine after i let it run for awhile? If I am wrong please correct me.

One more thing, since about 2 months after my dad got his quad, once in awhile the reverse light will flash on and off. We cant find anything about it in the owners/service manual, before we had the trouble with the bad gas in the carb the quad ran fine when the reverse light flashed, so I am clueless on that one.

Any help will be greatly appreciated.

 

I have to ask all the stupid questions first, sorry. Number one when you start up the bike from cold and use the choke is the emergency brake on? (if so take it off) Second, did anyone take the carbs off completely and then clean it? I would recommend only using the best pump octane fo a while to clean it out. Third if the first few items don't work check the plug, the tool to take it out is in you tool bag under the seat. Backfire is usually caused by running to lean and the plug would be very clean looking, you want a light brown color. Are you running any mods like the airbox lid off, if so put it back on. A black plug means too rich and your bad gas or if you rejetted it to much gas can do that. Your reverse light probably has a short or the contact wire is loose.

 

it could be a reverse rev limiter, that sensor is near the sprocket, its a green/white wire, ground that wire and try your quad, if it does the same, try the unplugging the other rev limiters

 

Yeah, I am going to check a bunch of stuff tomorrow when its not raining. As for the reverse light, its not like its not getting a good contact, it is a very evenly spaced out blink, I dont think the quad has a reverse rev limiter, i dont really know, i just know it hauls *** in reverse. lol. I will let you guys know what i find in the morening if its not raining.

Does gasoline go bad within 2 weeks of sitting?

 

i dont think so, unless its mexican gasoline[img]i/expressions/face-icon-small-tongue.gif[/img]

 

Well, there was a pause in rain, so I went out, and emptied the gas out of the carbs and tried it, and it didnt do anything. It runs fine with anything above half choke, if you take the choke off and just keep on the throttle, thats when it starts backfiring, then the second you let off the throttle, it dies. I have no mods or anything done to that quad by the way. After that it started raining again so I will check the spark plug tomorrow if its not raining.

 

Sound like it could be an intake leak. Check to see if the carbs are on the intake all the way.

 

I will check that, but the thing is we havnt even touched the quad since the last ride until today when we tried to start it, but you never know, I will check that in the morning as well. Thanks

 

I was having the same problem with a TRX90. Cleaned the float bowl and jets. Problem gone.

 

I had the same thing happen with the reverse light on mine twice, once the engine was really hot and I barrelled into a mud hole got stuck and the temp light and reverse light were flashing it also would'nt let the clutch disengage even though I had it pulled in. The second time I had a nasty wreck and bent quite a bit of stuff and after I flipped it back over my key would'nt turn the ignition back on and when it finally did the lights were all flashing. It has never did it again since but I am fairly curious about what might have happened. I would like to know were your getting your gas from so I can avoid that place, it rained every weekend for 4 weeks and I went out last weekend and it runs just as well as when I parked it.