I'm trying to find out about the jetti ng of the Raptor. The dealerships know nothing and there is no literature. I have read in a few posts on this forum about the raptor having a self adjusting jet. Would this be "fine tune" adjustments and or "large altitude" adjustments. When I take my toys to areas over 7000 feet, some I need to rejett and others work fine with stock. Does anyone know if the raptor would need to be rejetted for 7000 feet? If so, what size is the stock jet, so I can buy a smaller jett of the appropriate size.

Dinocrisis

Blue Raptor
Lakota sport
TRX 90
ATC 185
99 Dodge 4x4 (V-10)
XR 250
1976 CR 125 (Mint)

 

The factory jetting on the mains is 140 and 145 and they are the small round type. With all the stock parts on, I was slightly rich at 4000 ft with the ambient temp at 90 degrees F. So at higher elevations you would need to go leaner but then with the temperature decreasing this time of year, maybe not. If you do a search for my username (cruces) and search the Yamaha forum, I had posted on this some time ago. I did order richer jets from Carb parts warehouse http://www.carbparts.com/ but it took them three weeks to get to me and the two jets were $6.00 plus another $7.00 shipping and handling!

Lastly the Raptor carb bowls don't have the main jet access bolt on the bottom of the bowls like a dirt bike does, so you have to take the carbs off to change them (45 - 60 min). So I'm thinking of going to a cycle junk yard and getting another set of bowls with the bolt on the bottom and swapping them the next time I rejet.

 

can you give us a part# or name description of the jets used? When I called, they didn't seem to know what kind was needed.

 

on the carb parts.com page look at the tuning components for Mikuni and they are listed as the small round type. I've only seen four types of mains for Mikuni's the small and large hex, the small round and large round. Not sure if there any other types commonly used. Like I said before the threads on the mains seemed to go down the jet further on the raptor jets than on the ones I bought. I found most of the jets at the local dealers so they are pretty common. Also after rejetting and removing the spark arrestor and the air box lid extension and with a 12 tooth front sprocket I very quickly got up to 70 mph (GPS verified) on a dirt road. and don't forget I'm at 4000 ft.