M&M gurus need help!!!!!
Stellar HDF Member
Joined: Feb 2007
Posts: 2,558
Likes: 280
From: Russellville, Arkansas
Only person I knew that was an expert on the Magneti Marelli. He actually worked with Harley in the early 1990’s designing and tweaking that system. I still have a slightly modified throttle body never installed. Unfortunately, he’s passed away several years ago.
I kinda remember him saying setting those when the vacuum is at its highest point, but also keeping the smoothest idle. I’m only going off memory....so I could be leaving something out.
I kinda remember him saying setting those when the vacuum is at its highest point, but also keeping the smoothest idle. I’m only going off memory....so I could be leaving something out.
Seasoned HDF Member
Joined: Oct 2007
Posts: 8,852
Likes: 2,493
From: Decatur, Alabama
So where are these screws located? Are you talking about those two things that are covered over with epoxy in the intake?
Other question, is this an EVO or is it an early twin cam with the MM FI system?
carl
Other question, is this an EVO or is it an early twin cam with the MM FI system?
carl
Seasoned HDF Member
Joined: Aug 2008
Posts: 5,081
Likes: 2,159
From: Ohio
Did some searching and no technical information available on the secret screws, came up with adjusting the screws 1 1/2 turns out with installation of a Screamin Eagle Race Tuner and set the TPS before dyno tuning. I do know the small air ports at the plenum entry clog up with debris from the oil mist from the breather, carb cleaner can do wonders.
Only found 1 guy mentioning adjusting the screws multiple times in threads
"two screws top center of throttle body, dig sealant out and adjust similar to airfuel screws on carb, in for rich out for lean"
Red injectors support a SE-3 cam which is a EV27 without a tuner, the flash that comes with the Evo Screamin Eagle package only raises the rev limiter. Make sure your engine temperature sensor is working, you will be able to hear the tone plus rpm of the engine change when the ECM releases cold mode and the map takes over, if the the engine stays in cold mode from a failing ETC, the ECM stays locked in cold mode adding base fuel and your red injectors will add more. I had this system with the red injectors and you could not blip the throttle in cold mode, would hesitate (flat) and black smoke present.
If the sensors are all ok and TPS adjusted you might be able to tune the off idle flat spot out with the screws, I never had to mess with mine because it ran well with the SE package upgrade, with more cubes being added needed to start tuning with a AFR reader in a PC3 format.
Only found 1 guy mentioning adjusting the screws multiple times in threads
"two screws top center of throttle body, dig sealant out and adjust similar to airfuel screws on carb, in for rich out for lean"
Red injectors support a SE-3 cam which is a EV27 without a tuner, the flash that comes with the Evo Screamin Eagle package only raises the rev limiter. Make sure your engine temperature sensor is working, you will be able to hear the tone plus rpm of the engine change when the ECM releases cold mode and the map takes over, if the the engine stays in cold mode from a failing ETC, the ECM stays locked in cold mode adding base fuel and your red injectors will add more. I had this system with the red injectors and you could not blip the throttle in cold mode, would hesitate (flat) and black smoke present.
If the sensors are all ok and TPS adjusted you might be able to tune the off idle flat spot out with the screws, I never had to mess with mine because it ran well with the SE package upgrade, with more cubes being added needed to start tuning with a AFR reader in a PC3 format.
Thread Starter
|
Cruiser
Joined: May 2017
Posts: 125
Likes: 11
From: Wisconsin
That's some what helpful, that sounds like it may be what's happening, I can bench test the temp sensor and it works fine but yes it seems like it never comes out of cold mode. When was left as is for the screws and with just the mods, that's exactly what it did dumped fuel at idle. Now it runs ok cold and a little better when warm, but if I put the screws out 3 turns, is doesn't act lean it acts like it's rich, if I put them at 1.5 it runs decent to fair, it ran decent at 3 turns but only above 1500 rpms, it always had that flat so right around idle and didn't matter how hot it was you couldn't blip the throttle.
Stellar HDF Member
Joined: Feb 2007
Posts: 2,558
Likes: 280
From: Russellville, Arkansas
Harley 27615-00 SE Induction Module might be what you need depending on what engine upgrades you did. They weren’t very known about and only lasted 2-3 years. Delphi took over these became obsolete overnight.
Finding one available.....You have a better chance of seeing Bigfoot and a UFO!
I would be doing a carburetor swap at that point!
Finding one available.....You have a better chance of seeing Bigfoot and a UFO!
I would be doing a carburetor swap at that point!
Stellar HDF Member
Joined: Feb 2007
Posts: 2,558
Likes: 280
From: Russellville, Arkansas
There was one available for the EVO as well around the same time. In fact, the throttle body, fuel lines....etc. were all the same. The only difference was the downloadable flash cartridge and the head breather bolts. It was specifically designed for a Stage 3 EVO.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Seasoned HDF Member
Joined: Aug 2008
Posts: 5,081
Likes: 2,159
From: Ohio
That's some what helpful, that sounds like it may be what's happening, I can bench test the temp sensor and it works fine but yes it seems like it never comes out of cold mode. When was left as is for the screws and with just the mods, that's exactly what it did dumped fuel at idle. Now it runs ok cold and a little better when warm, but if I put the screws out 3 turns, is doesn't act lean it acts like it's rich, if I put them at 1.5 it runs decent to fair, it ran decent at 3 turns but only above 1500 rpms, it always had that flat so right around idle and didn't matter how hot it was you couldn't blip the throttle.
Those ETS sensors can be temperamental, I never had to replace mine but is the heart of that system