OK GOT A BUDDY THAT WANTDS TO JET HIS RAPTOR FOR HIS NEW EXHAUST. HE IS RUNNING A FULL FMF EXHAUST WITH A PROFLOW K&N AIR FILTER. (THE HEADER PIPE IS INCLUDED IN THE EXHAUST) NOW WE HAVE BEEN TOLD TO RUN A 150 AND 155 JET. IS THIS GONNA WORK? WE WE SUCKERED INTO BUYING THE DYNO JETT KIT FOR IT WHICH DIDNT WORK. WE PUT THE BIGGEST JETS THEY HAD (145 AND 150) AND IT WAS TOO LEAN. BESIDES RUNNING BIGGER JETS WHERE ELSE SHOULD I LOOK TO MAKE IT RICHER? I TOLD HIM TO MODIFY THE AIR LID OR REMOVE BUT HE DOESNT WANT TO CUZ THERE IS A TOOB THAT RUNS TO HIS MOTOR AND HE THINKS IT WILL HURT IT.

ANY INFO WOULD HELP.
THANKS
RICH

Im in the same shoes. I had got hte Dyno kit and I need to re jet it. instead of FMF though I have White Brothers E-Series. I also have 145/150 and I was told to try 150/155. I called the manufacture and they said to get the Dyno Kit. They had no spec #'s for me. But as far as removing the air lid, I did and just put a breather on that little toob. It's fine. Just filter it so you wont get any sand in their. Any update you get on the specs let me know so I can try it on mine.
Thanks :wink:

How do you know it is running too lean?

make sure you line up your advice on the number size of the jet with the manufacturer.meaning.dynojets numbers arent the same as mikuni

i have a yoshi full pipe and it didnt take dynojets biggest jets.it was one size down from the biggest.i was wondering if your air fuel screw setting is right.or maybe the clip position?

[quote]
i have a yoshi full pipe and it didnt take dynojets biggest jets.it was one size down from the biggest
[/quote]

Did you try the biggest? How did you know? Black smoke? fouling plug?

I am trying to minimize changing jets as it is such a pain in the neck to do!

I have the Yamaha GYT exhaust

K&N Filters

And just went one size up on the jets (Yamaha OTC jets).

My Raptor is an entirely different quad now.

Feels like the horsepower more than doubled. Probably didn't i know, but it sure feels like it did.

Also starts easy with no choke, a big improvement too.