Jetting for 366

Yamaha Raptor 350 & Warrior Forum

Help Support Yamaha Raptor 350 & Warrior Forum:

Superthrash1

Member
Joined
Jun 22, 2022
Messages
13
Reaction score
0
Location
Knoxville TN
Hello folks, racking my brain here trying to figure this out. I have a Raptor 350 that I recently upgraded to a 366. I’m having trouble with the jets. No matter what jets I put in it stumbles and dies when I give it throttle. I contacted the manufacturer and they said start with a 147.5. Went all the way up to 160 with the same issue. I’m new to rejetting, thanks for any guidance
 

ag2560

Well-Known Member
Joined
Mar 14, 2010
Messages
407
Reaction score
3
Did you change the pilot jet also the stock one is a 22.5. I would put a 25 in it also depending on the year you may have to drill out the plug over the mixture screw to fine tune it. They come jetted lean from the factory.
 

Superthrash1

Member
Joined
Jun 22, 2022
Messages
13
Reaction score
0
Location
Knoxville TN
Just ordered a set of pilot jets. I have a jet kit that came with my wife’s Raptor 350 that has a variety it mains, but no pilots.
 

Superthrash1

Member
Joined
Jun 22, 2022
Messages
13
Reaction score
0
Location
Knoxville TN
Been fighting with it all day. Again. It will idle fine with the 22.5 pilot jet, but no matter what main I put in, it stumbles and bogs badly. I can rev just a bit if I’m super easy on it. I went from 145-160 with no change. I tried a 25 pilot and it will rev good, but won’t idle at all.
 

beastlywarrior228

Super Moderator
Staff member
Moderator
Joined
Jun 29, 2009
Messages
6,740
Reaction score
76
Location
Mogadore, Oh
Been fighting with it all day. Again. It will idle fine with the 22.5 pilot jet, but no matter what main I put in, it stumbles and bogs badly. I can rev just a bit if I’m super easy on it. I went from 145-160 with no change. I tried a 25 pilot and it will rev good, but won’t idle at all.
You have another issue going on then. Could be the parking brake rev limiter.
 

Superthrash1

Member
Joined
Jun 22, 2022
Messages
13
Reaction score
0
Location
Knoxville TN
Got it figured out. Seems like the starter/air jet was the issue. Not sure if it was clogged, I just swapped it with another one and it’s all good
 
Top