ADJUSTING MagMarelli Air Bleed Screws?

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Jan 11, 2008 | 08:09 PM

gatorwalt

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ADJUSTING MagMarelli Air Bleed Screws?

I have an '01 Ultra with Manetti Marelli EFI, not keeping a tuneup. I took the throttle body off today, and found an air leak into one of the cylinders. Now, I need somebody to tell me the exact turns to adjust the two screws, front and back.

I was told 6 turns on the front, and 1 turn on the back. Does that mean whole revolutions, or "flats" of a screwdriver? Do I bottom each air screw out and then back them out 6 and 1 turns?

Please answer tonight, if possible. Bike down, rider on foot.......

Thanks mucho,

Gatorwalt
SEMPER FI
"We live in the land of the free, because of the brave."

Jan 11, 2008 | 09:39 PM

ajayrk

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RE: ADJUSTING MagMarelli Air Bleed Screws?

Gutman

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From Gutman's post it is 1 and 1/2 full turns from lightly seated. Be sure to count the turns as you seat the air bleeds incase you want to return them to their original settings.

I am going to use these settings on my 2000 R/K tomorrow.

Thanks Mr. Gutman.

Mack, you are incorrect. The SERT (32127-03A) is designed to work withthe M-M. The largest problem with the MAG system is in-correct TPS voltage and air bleed screws. We have not found one yet that has the correct TPS value and air bleed screws set at 6 turns front and one rear. These induction unitswere bench tested inItaly when assembled and then sent to York forassembly. They were not touched since. The TPS voltage controls fuel delivery and adjustment must be within +/-.02 vdc. This is challenging to achieve but will make a huge difference in runability. be sure to foloow the procedure in the service manual. One other tip is to back throttle cables completely off, and then tap the throttle plates with a screwdriver lightly to make sure they are completely closed. Adjust air bleeds to 1.5 turns from lightly seated. Complete this first, and tuning is a breeze. We have tuned many with good results. If this is not completed the tune will not be consistent, and even worse with the PC.

Jun 22, 2008 | 07:15 AM

newt615

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RE: ADJUSTING MagMarelli Air Bleed Screws?

ajayrk what was your factory settings on the air bleeds?, and how did the 1.5 turns out work for you? I've got a 2000 ultra with unsealed air bleeds and they are in tight but I've had some starting issues also and don't know if this is part of the problem. Are the bleeds useful on startup? the HD service manual says nothing about the screws, must be a big secret. thanks&nbsp\\;

May 27, 2020 | 12:25 PM

Frank Rositas

Stage II

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From: Galt

Bleed screw settings

Quote:

Originally Posted by gatorwalt

Did adjusting your screws to 1.5 turns front and back work? I've been having a hell of a time getting my classic to run smoothly.

FRANK R.
SEMPER FI Brother.

Dec 9, 2020 | 05:14 PM

Garageking

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From: Athens Ohio

Is it advisable to count turns in to seat, remove and clean passages, and reset the idle air screws on the M M system?
I have my IAC and TPS tuned up and it made big difference, but have yet the mess with idle air screws. Gonna dig into my manual this weekend, but its a Clymer. Not bad but not FSM. I had to fix intake seals when i got the bike this spring but i have not done any TB cleaning yet.
98 FLHRCI lots of miles.