Cafe Racer Forum banner
1 - 5 of 5 Posts

·
Registered
Joined
·
185 Posts
Discussion Starter · #1 ·
I've read that on the Mikuni the main jet only controls 3/4 to full throttle.

If this is true, how come now that I put a 130 main-from a 175- does the bike not run as well accelerating from idle???

Was perfect there before... stock cb350 with Mikuni vm30.
 

·
Banned
Joined
·
5,783 Posts
What you read should have said the main jet primarily controls 3/4 to full throttle. There is always some flow though the main jet but it small throttle openings it is fairly negligible, but that is why the jetting procedure specifies doing the main jet first, then the needle and lastly the pilot, followed by the air screw. All of the circuits have some overlap and effect on the whole range of operations. You may now be lean in the midrange and have to raise the needle a clip. Then you may end up lean on the pilot and have to go 1 bigger on it too.

If jetting was real easy, everybody could do it. that is why you can't just put a pipe and filters on a bike, go bigger on the mains and have it work out.

Ken
 

·
Registered
Joined
·
185 Posts
Discussion Starter · #4 ·
I double checked the cables seating and re did the idle and now it seems negligible. And better up top. i might try to adjust the needle slightly, but seems pretty good now.
 
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top