quick jet kit question

[3LK1-FZR]

ok i got my Factory pro jet kit and there are 2 sizes of main jets. 130's and 127.5's do i need to order two more of each jet sizes? ive never been into carbs like these before.

[sweekster]

Nope..that's how it's supposed to be. I have the 130s in the two outer carbs (cylinders 1 & 4) and the 127.5s in the center carbs (cylinders 2 & 3) and my bike runs awesome now.

[3LK1-FZR]

thats odd....but ok. do you know of anybody that sells a re-build kit for the 1K carbs???

[sweekster]

The stock jets are two different sizes as well (122 and 125 i think). Rebuild kit? Not that I know of for the 1k. I got all what I needed from Cyclepartswarehouse.com.

[3LK1-FZR]

thanks i will check them out...

[yamaha_george]

thats odd...

Hi,
Not really if you think where the leaner jets are being placed EG. in the center 2 cylinders which are subject to more heat which I suppose is counter intuitive.
You would think the center 2 would be richer in fuel cooling the bores .

[mossy1200]

thats odd...

Hi,
Not really if you think where the leaner jets are being placed EG. in the center 2 cylinders which are subject to more heat which I suppose is counter intuitive.
You would think the center 2 would be richer in fuel cooling the bores .

With stage three it can be best to run all same and turn mixture up on centre two cylinders by quarter turn.
Blocking air jets for stage three changes the way the carb delivers(this is why the jets are smaller in kitted carbs.The pressure sucked up the main jets become higher with the air jets blanked off.this causes a increased volum high pressure spray going up the emulsion tubes.
its very common for guys to over jet the mains and then try compensate with the needle height.

[3LK1-FZR]

i have to be honest but ive never jetted a big 4 cylinder 4 stroke before. all of my tuning knowledge and jetting have been done on my other bike. my 77 RD 400. easy to get to the carbs and half as few parts to order

[yamaha_george]

my other bike. my 77 RD 400. easy to get to the carbs and half as few parts to order

3LK1,
OMG another RD nut if you need a fix for your RD habit see:

http://www.saltmine.org.uk/kgb/2stroke.html

Y-G (owner of 7 RD400's & certified RD addict )