HEY GUYS. I'VE HAD MY RAPTOR FOR ABOUT 4 MONTHS NOW AND HAVE HAD NO PROBLEMS UNTIL LAST WEEKEND.IT'S BACKFIRED AND BLOWN THE CARBS OFF TWICE AND THIS LAST TIME IT BLEW THE INTAKE MANIFOLDS OFF TOO! THE YAMAHA DEALER HAS DONE EVERYTHING THE CAN THINK OF FROM VALVE ADJUSTMENT, CARB JETTING AND TIMEING. PROBLEM IS STILL THERE. AT A HARE SCRAMBLE THIS WEEKEND TWO OTHER BIKES EXPERIENCED THE SAME THING.IF YOU OR YOUR DEALERSHIP HAVE ANY INFO PLEASE PASS IT ON TOO ME. I HAVE A BIG RACE COMMING UP ON THE 27TH. NEED HELP!

 

maybe you should have another dealer cheak it out. i live in a small town and three raptor were bought here each one from the dealer including mine had the carbs bow off omost ever time we went riding so i toke tools to fix it until the break in time was over to adjust the valves it even cracked one of my boots. after the valve adjustment none of these raptors had anymore problems. they also loosend all the bolts on my air filter box all they way up then retightend to get a snug fit

 

Raptized,

I recently had a posting on the same issue. The responses I got were similar...adjust intake box forward and richen idle air adjustment. Yamaha either had a tech advisory or they responded the same way to dealer inquiries, because my dealer did richen idle when they replaced them the first time, but they did pop off again...I'm awaiting rebooting, but I personally richened idle and it seemed to help...maybe a little more sluggish start, but no sneezing at least. Also, don't touch the throttle at startup. This seemed to keep the "lean" condition at bay. In the meantime, I tightened the boots to the carbs a little snugger than what the dealer did...just in case...watch extreme tightening as boot will roll on the edge and not seal well, and/or as the previous thread will tell ya, it can bust the boot like a balloon...good luck...keep us informed.

 

Would you like to know the fix? It's not valve adjustment or timing or air box position..........what is it? Lean Pilot jetting! Call www.Sudco.com tomorrow and tell them to send you a set of 25's for the Raptor. When you get them, install them with your adjustment screws at: left-3turns out.....right-1.5 turns out. Just try this and thank me later. I am shocked a lot more people don't have this same problem. This is no joke....I've been there and done that.

 

actually I had not had this problem where it blew the carbs off, but it did back fire slightly once after I took off on it cold, I checked things out recently, My plug was sooty and black and it would cut and backfire slighly when revving up. I changed the plug, cleaned out the horrible oil in the filter and sprayed it with a little PJ1 filter oil, and squeezed out the excess. Needless to say it is as good as new. But for those who are blowing the carbs out. increase your idle and adjust the airscrews if you know how, if that doesnt work then rejet.