Author Topic: Mikuni pilot air screw ajustment  (Read 1076 times)

0 Members and 1 Guest are viewing this topic.

RMJJ

  • Guest
Mikuni pilot air screw ajustment
« on: August 09, 2010, 08:39:54 AM »
81 RM125 32mm round slide
I tried to set my air screw at the meeting today before the first race.
Was in a rush so gave up and just went out on the thing.

I fully warmed the bike up, got my mate to hold the throttle dead steady at tick over while I turned the screw. It made no difference whatsoever. I turned it  nearly fully in and 2 turns out from 1.5 turns standard position.
The revs did not change one bit. Nothing nadder didly squat happened.
What does this mean ? Too big jet too small jet ?

Offline Stevo17

  • A-Grade
  • ****
  • Posts: 374
    • View Profile
Re: Mikuni pilot air screw ajustment
« Reply #1 on: August 09, 2010, 08:45:42 AM »
Hi RMJJ, possibly a too small a pilot, or could even be an air leak. Check for air leaks around reed valve, base gasket or crank shaft seal.  I had a similar problem and it turned out to be an air leak around the reed valve.

Offline JohnnyO

  • Legend
  • *****
  • Posts: 4658
  • Qld
    • View Profile
Re: Mikuni pilot air screw ajustment
« Reply #2 on: August 09, 2010, 09:21:47 AM »
Possibly an air leak or a blocked passage in the carb.

Offline micks

  • A-Grade
  • ****
  • Posts: 471
    • View Profile
Re: Mikuni pilot air screw ajustment
« Reply #3 on: August 09, 2010, 08:09:39 PM »
i have seen the very tip of the air screw break off in the carbie. someone had tighten it down to hard.