My carbs popped off, but only once so far. I bought it new, and this one's got no mods whatsoever. It's always been ridden at the same altitude (about sea level). It sounded like a gun shot when it happened.

 

I am getting tired of hearing about this issue. Too many people are bad mouthing raptors or 01 raptors or raptor intakes. Let's look at the facts:
Carbs should not "blow off". There is actually a suction on the carbs from air flowing (at a high rate of speed) past them to the intakes. If your carbs have blown off it is as a result of a reverse pressure on them (assuming you tightened the clamps right and they didn't just vibrate off).

So... if there is a backward pressure on the carbs, it is as a result of backpressure (backfiring) coming from the engine.
The Cause: ill adjusted valves. Gentlemen, the majority of raptor carb problems arise from people not checking their valves after break in. Raptors are water cooled and like most water cooled engines, tend to have their valves tighten over time. When this happens, the intakes can be partially open on the compression stroke allowing combustion to blow back through the intakes and force the carbs off their boots. The problem is engine maintenance. NOT faulty carbs. And just because you can't hear the bike backfire doesn't mean its not happening. And for those who have bought new carb boots or clamps or intakes, you might want to check your valve tolerances. You still have a problem, you have just bought parts that keep you from knowing about it.

~HoundDog

 

hound dog you are half rite ,,its also a lean backfire{you dont hear}so we all richen up our idle jets,which we had to pay for,thats my beef they,yamaha, should at least supply us with parts instead of stupid answers like "you need factory jetting" well being my quad came from a hollow tree and was baked by elves.or" its not warmed up" when it happened on a 85 degree day 5 miles from the starting point. its something they should just recall and fix...what about the one way and the tranny?they wont even admit it at the dealers.i just put the carbs back on a2002 that blew off so its not just an 01 DEFECT the boots are also not stiff enough so they bellow and rip in just two years,i see 1970 bikes with original boots.yamaha has DEFECTVE boots on our raptors.....i love it when all is well with it it rips.