Hey Guys,

My '96 fxds will make a loud pop(backfire) from the exhaust when starting, after I have rode for awhile and I restart after sitting a short period(getting gas). It just started after we got some hot weather, If the engine is cool or has cooled down awhile it doesn't do it at all.

My wife and I rode up to Lake Tahoe over the weekend and while there it did not do it at all, it was in the 80's there(and of course the bike was running richer because of the elevation). When we returned to the mid nineties and lower elevation it again poped after getting gas .

Otherwise the bike runs and starts great.

Any ideas?

Are you twisting the throttle when starting it up warm? If so, then that could cause a pop or backfire.

No, I dont, I also thought maybe i was doing that without thinking, so I paid attention to not touching the throttle and it still popped. Today is a cool day in the 70's and I rode it and there was no popping during several restarts.

Mine does the same thing when its hot, if I leave the fuel on,if I shut off the fuel, even just to get gas, it dosent do it as often. I installed an aftermarket fuel shut off thats easy to flip back and forth to make it easier.

__________________
http://i220.photobucket.com/albums/d...0963-1-1-1.jpg
1992 FXRS Lowrider

My '91 does the exact same thing... drives me nuts. It pops right when I flip the kill switch (before I hit the start button). I suspect it's an ignition issue. I checked all the ignition wiring, coil, etc, cleaned the wire terminals, and I even took apart the ignition switch and cleaned all the contacts in there. But it still happens. I'm planning to change out my ignition system soon though, so we'll see if that makes any difference. What ignition are you running?

Do you rev the engine before shutting it down? I think the pop is worse on mine if I give it a good rev before shutdown... probably from unburned fuel left in the cylinder. If I just kill it without a rev, the pop ends up being just sort of a whoosh of air.

My 98 LR does the same thing sometimes. Sounds like a friggin .45 being shot off. Doesn't seem to do it if I give it some gas when I start it and I never know when it is going to do it. It's kind of embarrassing sometimes because everybody around ducks for cover then they all stare at me. When you get it figured out, please post it so I can fix mine to, lol.

__________________
98 Lowrider w/couple of minor mods to make it a 3/4 Stage, but I'm still workin on it, and before I die it will be a Stage 1, LOL.

Guys, have a look at my post under Timing Help!!!!!!!!!! I don't know if you have the same problem but I had the same as you are describing and I have now fixed mine.

Cheers.

I always turn off the petcock when I stop, even better if you turn it off just before parking as it burns the gas in the cylinders up.

My 97 heritage does the same thing, just not every time. It don't bother me. It's not fuel infected, it's 11 years young, and it's kind of funny at a crowded gas station. I usually start talkin like Yosemite Sam and it draws a chuckle. It happened last week, and my buddy yelled out, "where here for the Woman and the Children" everyone laughed that time.
&nbsp\\;
it's nothing to worry about, it's just a little gas..

__________________
Trust Everyone you meet,
But have a plan to KILL everybody, just in case..

Suck, Squeeze, Bang, and Blow...Potato for short..

Its called a "Harley fart." Not a problem unless you piss your pants. JMHO, YMMV, etc.
&nbsp\\;\\\\\\;
Bob