Ok, got a problem that has been giving me more gray hair (and I don’t don’t need anymore) I put a Daytona twin tec ECM on my 99 FLH , carb model ! Following the suggested starting point of 2 and 2 ( initial timing and advance timing ) ! You are to adjust ( advance both ) until detonation or spark knock and back off ! My set up is 1550 big bore kit , Andrew’s cams , head work ( ported / polished) screaming eagle carb (40mm) free flow AIR filter, Reinhardt true duels exhaust ! Bike runs f’ing great with settings of 3 & 5 but will spark knock ! Trying backing off all the way to starting point and lower ! Tried giving it more gas, went from 45 low speed to 48 , high speed jet 195 to 205 ! Still detonation !!! Checked exhaust, no leaks , checked manifold no leaks !! Going to raise needle see if that can give enough gas to stop the spark knock ! Planning on a trip to the west coast in 3 months hopping to figure it out before I leave ! Anyone in the group have a similar problem ?? Oh and running colder plugs too ! Was getting 42mpg”s before changing ECM , with the same set up, that’s in the toilet now ! Reason I went with this unit ,Harley quite making the SE ecms which i was running with no issues ,logged over 200k with it , but than it died . Manufacture says add more gas.Have had it in the local HD shop with no help, or answer! The guy with his own back yard shop ,same results.

 

If I'm understanding correctly, the Daytona Twin-Tec you are using is only controlling the spark? It is NOT the "ECU" that uses the wide-band oxygen sensors?

Sounds like a spark timing issue to me. A lot depends on how much adjustability you have with the Twin-Tec and where you are getting the knock. Is it WOT or part throttle roll-on? Way different areas to deal with. Give us a little more information, and while I'm not familiar with the Daytona Twin-Tec offering, I'm sure someone will come along that has used it to good avail.

 

Just a thought could your fuel be the problem???? Bad gas low octane etc

 

You may want to ask this in the Ignition/Tuner/ECM/Fuel Injection forum.

 

You don't have an ECM, you have an ICM (Ignition Control Module)... there is a difference between the modules on an EFI bike and a carb bike, simple terminology maybe, but two totally different modules...... The ICM controls timing/advance curve...

Was it running well with the carb set-up (jets and mixture screw) before you added the ICM....??

If you went to 3/5 on the ICM and it knocked, how far did you have to back down before it stopped knocking...??

The one time I used the Twin Tech ICM on a friend's bike, we set up the carb first... Then we played with the Twin Tec timing.. just like in the video below, we bumped it up until it had detonation, and then backed it off... It was awhile ago, but I remember it as a pretty easy tune procedure... and his bike ran great when we were done..

See if this helps...