Did I make a mistake?

[presh223]

I sourced a carburetor from a 2001 rm 125 to install in my 2002 RM 125. As I'm having trouble with jetting I'm curious if I made a mistake? The 01 factory spec shows 210 Main jet and the 02 has a 460 main jet. Different pilot jets as well. I don't want to ruin my motor by running specs for a different machine even though I was understanding that these bikes are virtually identical? 

[schrode]

sounds like maybe they were using a keihin in '01 and a mikuni in '02. what carb did you buy?

[RippinLT]

Use the specs from the 01 since that is your carb. I had a 98 rm carb on an 03 bike. Use the jetting specs from the carb year. The engines are almost exactly the same throughout those years, you may have to go up or down a size in your pilot or main but the stock specs will be in the ballpark.

[presh223]

sounds like maybe they were using a keihin in '01 and a mikuni in '02. what carb did you buy?

I think they are both mikuni. I purchased a spare parts bike ('01) and am cannibalizing things I may need for the '02 including the carb. 

[presh223]

Use the specs from the 01 since that is your carb. I had a 98 rm carb on an 03 bike. Use the jetting specs from the carb year. The engines are almost exactly the same throughout those years, you may have to go up or down a size in your pilot or main but the stock specs will be in the ballpark.

Rippin LT, thank you for the advice. I ended up finding the jet sizes for the '02 which FMF recommends for their pipes. So from a stock 460 main I went to a 430 and from a stock 40 pilot I went to a 27.5. This is so odd because FMF suggests to use a larger main jet for the '01 than the '02. They recommend 450 for the '01. So I guess logic would suggest to use in between at a 440, but I installed the 430 last night as well as the pilot 27.5 and the bike ran amazingly crisp. I was having most issues with the main, but I guess it's all remedied now. 

[RippinLT]

Wow you went from a 40 pilot down to a 27.5? I'm having low rpm issues. Maybe I'll do the same!

[presh223]

Some sources report that the '02 came or was designed to function with a 32.5 pilot, but in my moose carburetor kit a 40 was supplied. I actually didn't have any issues with the 40, opted to use FMF's guidelines for jetting. I think somewhere in this jetting range is appropriate though because this bike screams. I haven't used it extensively so who knows how it will perform. Good luck. 

[kaotickawikxf]

most of the time those moose and dyna jet , jet kits put there own number ranges rather then mikuni and kehin jet true sizes as well... just a little snapple fact for ya from dealing with these companies on a regular basis