Bike nube

[XJNate]

Hey there, I think I've concluded that I have a 1982 xs400SJ and I'm looking to purchase new Jets. Looking at a few posts on here it appears that the main jets are different each side. I'm looking here:

http://www.boats.net/parts/search/Yamaha/Motorcycle/1982/XS400SJ/CARBURETOR/parts.html

there are two listed main jets. Do I just order both? is the 155/135 the size difference? which side is which?

JET, MAIN (155)
3G2-14231-31-00


JET,MAIN 135

620-14231-27-A0

 

[NewHavenMike]

The jets should be the same in both carbs. They were probably changed in between some years for emissions or different carbs.. I dont really know model details year by year though. Buy everything carburetor related in pairs, for both carbs.

The #155 jet according to the diagram, appears to be one of the external air jets. Pretty sure you dont have to touch these, as the opening in them is larger and doesnt really get jammed and really never needs to be removed.

If you have a factory exhaust and airfilters, you shouldnt have to to rejet.. The stock jetting setup is the best setup to have with a stock bike.

When you modify, thats when you need to rejet. In that case, You simply dont just get bigger jets and run it, it requires quite a bit of tuning from full throttle down to an idle.

 

[xschris]

There was a sohc xs400 and a dohc xs400 for 1982. The dohc xs400 and the sohc xs400 are different bikes. Make sure you get the ones for the bike you have. Post a pic of the bike so we can see. The sohc used a 135 main jet and a 155 air jet. The dohc used different sized mains for the left and right carbs. I think they where 125 and 120. The 82 SJ is sohc. The RJ or J is dohc.