My Alba pipe came with a 150 jet when I bought it some time ago. They said take the 140 out of the left carb, replace it with the 145 from the right carb and install the 150 they gave me in the right carb. Well experimenting with jets led me to the 150/155 setup I'm useing now. I purchased several jets to do this. 155,158,160,162. These were all Chaparral had at the time. I tried them all up to the 162. I went in today to finish the set up to 175. The guy today is telling me Yamaha only makes jets for the Raptor up to 150. The jets I purchased before are from Keihin. I took the 140 in with me to match up when I bought the first set. He says that after 150 the Keihin will not fit either because the diameter of the jet is different, he says the service department confirms this. I told him I already had installed up to 162 before and they fit fine. Putting the 140 jet up to all the others they are the same thread and diameter. These guys must be tripping. I purchased a 165, 170, 172 anyway. Any one else have any experiences as this? What brand jets are you running other than Dyno jets?

 

THe guy clearly does'nt know what he is talking about. Find a local speed shop or a more knowledgible parts department....tell them your carb type and you need the "small round" type of main jet. Should be a piece of cake.

 

I have only seen the mains in size differences of 5......www.sudco.com confirms this as well.

 

If I remember correctly, they are called "Mikuni small rounds", and the shop says that they are a very common type.

Good luck,
Lorrin

 

Mikuni small rounds are definatly whats needed. The keihin sizes ive described work just fine. I think I will hunt down some Mikuni small rounds though. Thanks for the replys.