I bought a used Raptor a month ago. Lots of goodies on it. Pro Design foam filter, CT full exhaust with race tip (not discs), A-arms, axle, shocks, ... Anyway, it ran like junk at full throttle (perfect everywhere else) from the very first ride. Had I known it wasn't going to run properly, I probably would not have bought it, but I digress. The previous owner claims it ran perfectly for him at roughly the same altitude (sea level - yeah sure it did). Anyway, it ran much better with the lid on as best as I could get it, so I jetted the mains up. He had Dynojet 146/150s in there with the stock needles at the 4th clip. I put in Mikuni 170/175s, and it was much better with the lid off, but kind of flat from 7/8 throttle on up. No missing or backfiring, just a little less power or no extra power at full throttle from 7/8. Then I taped half the airbox off with duct tape and it ran great, bottom to top with more power on top than before. So I figured I was still a little lean, although I didn't understand how I could be with 170/175 mains. So I jumped up to 180/185 and then 185/190s with no difference in performance. It ran almost the same with the 170/175s as it did with the 185/190s. No missing or hesitation, just no extra power. With half the airbox taped shut, it ran like a dream, which again told me that I was probably lean.

I checked the intake boots and didn't notice any cracks. The header bolts were tight, even when the engine was warm. I couldn't feel any leaks anywhere in the exhaust. So I checked the floats, and they were right on at 13mm. I decided to raise them up a few mm, and that made no difference. I even went so far as to swap in the carbs from my other Raptor, which runs great (stock). I switched in the higher needles and bigger jets from the other carbs and tried it out. Same problem. I am now the pro at ripping the carbs out of Raptors, but still have the problem.

Anyone have any clue what is going on here?

 

How old is this Raptor? does it have a cam? Check your valve adjustment. The valves springs or valves could be tired depending on how much time is on the motor. That could effect the top end performance. Even with the iar box partialy tape off it would appear to run better because you are most likely not hitting the same rpm levels. What gears are in it?

 

Airraptor,
I kind of like the disc-based systems because you can change from race tip to discs to decrease the sound output and add a spark arrestor to be able to ride on state land (with a jetting change). The CT also uses allen bolts rather than rivets, which makes changing tips easier.

RaptorRRC,
According to the previous owner, the motor is stock. It's a 2001 with (are your ready for a big surprise here) a new 2001 tranny in it since the first one lost second gear. The owner had to cough up the entire $1000 to repair it since it was out of warranty by 6 months. The best part is that the '02 gears were out by then and they dealer still put in '01 parts. But again I digress. I believe it's got the stock front and rear sprockets on it.

I feel the lack of power at full throttle even before the revs pick up, so I don't think it's the cam. I didn't check the valve clearances, but it certainly won't be difficult now that the front plastic and the gas tank are off. It revs equally high both with the air box taped and without. It just pulls harder at full throttle than 7/8 with the box taped.

 

Any other ideas? I've been riding the stock Raptor since I haven't gotten this thing figured out yet. If I had the discs, I'd try them out, but the previous owner is dragging his feet getting them to me. I still think I should be able to get it running right with the race tip. I guess I could always ride it with my custom duct tape half-sized airbox lid installed. Probably wouldn't hold up too well in the wet stuff, though.

 

I think by putting the disc's back on your problems will cease. I have also heard this pipe is extreamly hard to jet even with discs on. The straight through tip is just compounding the problem!

 

Do a full throttle run and cut the ignition off.....coast too a stop.....AND CHECK THR SPARK PLUG! THen, go up or down....your engine will tell you what it wants.

 

you said you like the disc system so whats wrong with the e-series pipe?
i had the ct sonic and had the same problem you had...all i did was get an e-series and a #9 plug im running 150/155 and 27.5 pilots. i'd hate to see another raptor rider melt down[img]i/expressions/face-icon-small-tongue.gif[/img]

 

GaryC,
I'm kind of reluctant to do a wide open throttle run of any length seeing as the troubleshooting I've done at this point tells me the thing is lean at full throttle (1/2 an airbox lid = problem solved, no airbox lid = same old problem). I only have it at full throttle long enough to tell what the difference is from 7/8 throttle and then I'm back to half throttle or less to get back to the garage.

RaptorRyan,
Unfortunately I'm still waiting on those discs. I'm getting ready to fly down to Georgia and kick the hell out of the guy who I bought the thing from. For now, I'm stuck with what I've got which is my hand-crafted, half-sized lid made entirely of genuine duct tape.

RideRaptor420,
The E-series was certainly on my short list, but from what I remember reading, the discs are riveted on? I know the CT discs are held on by allen screws, which makes it a bit easier to change setups depending on where I'm going to be riding. I'm a regular pro at rejetting the Raptor now, so that's not really a big issue anymore.

Everybody, thanks for the ideas. I'd rather not give up on this pipe yet. It may not be the pipe to own if you want to make friends on this forum, but it's the one I have installed.

 

no these disc's are also used with allen wrenches because the pipe to completly tunable...hope this helps[img]i/expressions/face-icon-small-happy.gif[/img]