96 fatboy stock engine, crane HI-4 ignition. Cuts out on acceleration. cleaned cable terminals between battery - frame seemed to run OK for about 10 miles. Now idles good but when I try to accelerate backfires and cuts out. tested plugs out of the cylinders looks like getting good spark, coil to spec, timing is set to TDC. What am I missing?

 

Initial dumb question..
"1996 Fatboy", or "96 CI FatBoy Stock Engine"?

if the former, have you tried cleaning the carburetor?

 

My '03 did that, turned out to be a busted post on the rear plug. You couldn't tell anything was wrong with it. Changed out the plugs and busted the ceramic on the old ones and found the break.

 

my fatboy was doing the same thing, turned out to be the intake gaskets

 

The engine is stock. I was told someone had gone through the carb before. Initially thought it was electrical/ignition. I'll pull the carb tomorrow and go through it. I tried the brake clean towards the intake seals when idling and didn't detect a leak, although the rear plug is more sooty than the front. Thanks for the direction/ideas.

 

If it's the stock CV carb, take the top off and inspect for holes in the diaphram, and also, make sure the accelerator pump is squirting fuel into the throat of the intake when you open the throttle.

 

carb is OK, intake gaskets good.
can the control module be the problem?
how do you check it?

 

Is your Crane a separate module, or is it the type mounted under the timing cover on the bike?

The one's under the cover were never rated very good and often too much heat made them fail.

If it's the Ignition module, mounted somewhere else, the best you could do is borrow a stock module and swap them out to see if the problem stops.

 

The crane HI4 is in the nose cone. I'm thinking its the ignition module because the problems are so sporadic. One ride there is a rare backfire. The next the bike bogs down and almost dies over 45 mph. I try to accelerate and no reaction unless I slow down the bike somewhat recovers and can limp home a couple of miles.

 

Make sure fuel pick up has no small leaks...my 02 softail was starting and idle/low speed ok but would bog down and sputter/backfire when accelerating after warm...sometimes