Raptor Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
HELP!!! I have a 2001 Yamaha Raptor 660 and i have been trying to get the carbs adjusted and I just can't seem to get them how many turns out from fully seated should the air/fuel mixture be?
 

·
Super Moderator
Joined
·
8,011 Posts
I moved you into the 660 forum, get a quicker response I am sure.

Do you have a service manual for it?
 

·
Registered
Joined
·
3 Posts
Discussion Starter #3
All I have is a disc that is like a service manual but all it says is to count the number of turns it was set to before you disassemble and clean it doesn't tell me a preset to turn them to
 

·
Super Moderator
Joined
·
17,057 Posts
Tune them, they don't have to be in one particular position.

Try 2-2.5 turns on each, you may or may not want to stagger the right carb 1/2 turn more than the left.
 

·
Registered
Joined
·
12 Posts
Hi I'm new to this site and kinda working on engines in general. I just bought a 2001 raptor 660 an its backfires a lot when going through the gears or slowing down. So I checked out the air filter and it was clogged with sand so I took it off to clean it and noticed there was sand going up through the air hoses into the carburetor. I'm wondering if cleaning the carb will do the trick or what else I should do or inspect?
 

·
Master of the Electron
Joined
·
14,760 Posts
WAYNE - you are confusing two different things - each carb has a PILOT JET and a PILOT SCREW (sometimes called 'fuel screw'). The pilot jet controls how much fuel gets to the engine during idle and up to about 1/4 throttle. The pilot jet will have a number (probably 22.5 or close to it) on it. The pilot screw acts like a valve to adjust this fuel from the pilot jet - the jet controls the max flow, the screw just can turn flow down.

The carb also has NEEDLE jets and MAIN jets - the needle jets control fuel flow from about 1/4 to about 3/4 throttle and get moved up and down in their bore (adjusting fuel flow dynamically) by vacuum from in front of the butterfly. Main jets control flow from about 3/4 to full throttle - mains will have numbers somewhere between 140 and 170, if they are typical Mikuni brand.

So with this info in hand, what is your question now, Wayne?


Travis - this is your 3rd post on the same issue - the moderator is gonna get mad at you! :wink
 

·
Registered
Joined
·
2 Posts
hey so i have a 01 yamaha raptor 660r with a slip on HMF exhaust & i have the jet kit for it i just want to know what jet to use in the carbs and what is the adjustment i need to do so it can run good and everything else is all stock
 

·
Master of the Electron
Joined
·
14,760 Posts
stock jets
 
1 - 12 of 12 Posts
Top