What can I do to improve performance on a marreli injected bike, 97 flh.


Will the usual AC and pipes, screw up the efi?


I already have a ev13 cam.


I know I can change to a carb, but I'd like to find some info on the efi first, if there is any.


Thanks

 

A/C and pipes are a marginal upgrade, cam a bit more. You should probably be using a fuel management system such as a PC III USB. To not do so risks your motor due to leaning out. Next up would be the red injectors.
I have a hogged out and polished throttle body with the red injectors I don't use now because I went to carb this year.
If you don't know how to adjust the PC III, a dyno tune will get you the max HP for your mods.

There are others here that probably add to this.

 

You answered your own question...Carby is the best upgrade for MM EFI...

 

We have other members who think that MMI can be sorted out and doesn't deserve the bad press it gets, hopefully they will be along soon. In the meantime use Search for 'PC III' and you'll find some recent discussion on using it, especially here.

 

Here is what I did, took the throttle body and cut it in half before the runner bend, removed the center divider and tig welded it back together, this removed the restricted shotgun design. Did a port blend with a tooled finished surface that creates slight turbulence for fuel not to puddle, with the shotgun design removed it allowed the intake to cross talk that provides a carbed Evo idle with a EFI but a larger duration cam is needed to do this. This mod required more fuel to be added because more air going in, have a data recording system that can build maps so the measurement wasn't by guessing.

M&M mods still isn't going to be magic for a good running Evo, the base engine needs mods for it to ask for more fuel, EV13 is good for low power but falls on it's face quick, I wouldn't spend much time messing with fuel delivery on it. Now if you jump to the world of Woods 6 or EV27, add a 2-1 exhaust, red injectors, PC3 with a dyno tune then your talkin improvement, Dynojet or Fuel Moto can supply you a map that is close but not perfect.

Another note is the SE stage 3 mod for the M&M is red injectors, SE3 cam which is a EV27, air filter and a download that is supposed to raise the factory rev limiter, that is what was in my bike when I bought it and ran ok.

I powered a 100 hp with a M&M system but going to be honest with you, a prepped CV or Mikuni will out perform the Italian system so dinosaur technology still wins on a Evo but the M&M can do what you want and be reliable if you understand it.

 

My Marelli injected '99 Twin Cam makes 100/100 and has 154,000 miles on it. There might be more in mine but the injector duty cycle is maxed out (for now). If you go with red injectors you also need to add a higher pressure regulator.

The throttle body beemervet mentioned above undoubtedly has a 58 pound regulator in it, which is what you would want. If he'll let the throttle body go reasonably, I'd jump all over it if I was you. In fact, if it's reasonable, and you don't want it, I probably do. I'm kind of hoarding MM parts as I'm keeping my current bike until I drop dead.