Greetings,


Got a 89 FLTCU that is pride and joy. She is starting to backfire when going down road. It happens 20 or 30 min into ride, and will stop when cooled off a bit. Would appreciate advise. willing to start the parts changeout. Any ideas? Thanks Mack

 

Hi Mack and welcome to HDF from the UK. You're in good company in here and plenty of us have bikes of a similar age. Our experts will be along shortly with some hints and tips!

 

What you checked or done so far to correct the problem?

 

Is it backfiring out the carb or exhaust? If it out the carb...more than likely an intake leak.

 

It is backfiring out of carb.
To date have changed. V.O.E.S. , plugs, wires, dealer changed sensory plate,
checked intake leak with starting fluid to hear idle speed up, it did not change
Cold it runs fine, only acts up when warm.

 

Exactly is it a sneeze through the carb while small increases of throttle or a poping out the pipes while decelerating..? Dirty carb jets causing lean condition maby. Since you already ruled out intake air leak.

 

small backfires through carb, but still can maintain highway speed.
when I get on it hard it runs better. when I back off throttle and get back on it, that's when she gets mad
the carb just slip fits into a rubber intake(snugly) no clamps though

 

Spray carb cleaner on compliance fitting to find a intake leak
Oops, never mind. Clean carb and put in line fuel filter, check tanks for sediment.

 

It can't hurt to replace your intake gaskets anyways... When I bought mine it was doing that very thing, but ten times worse. I sprayed everything I knew of at the intake and couldn't get it to change at all. I pulled the carb off and checked it out, and it was clean, jets were clean, but I replaced the intake gaskets anyways and that fixed it until the cam bearing went.

 

Unfortunately there are no intake gaskets on an `89 or earlier, they used those lame butterfly type carbs and the infamous compliance fittings...

OP:

If you are still using the original butterfly type carb, it may be time to think about replacing it, rather then spend money for new compliance fittings, carb rebuild kit etc.