engine running rough, backfiring

 
Shirley, please dust off the Knob Creek and pour some long shots for them as
wants 'em. My 99 FXDX has about 55 thousand miles on it, and now wants to run
rough, and lurch and backfire when I ease off the throttle. Thinking it was
bad gas - small town and not a lot of turnover on the hi test stuff - I dosed
the tank with alcohol to deal with water. Well, no improvement. Next line of
attack was possible air leak in the intake manifold seals. A toot of WD40 in
the vicinity, while the engine was idling, and I *thought* maybe there was
some improvement in the rhythm of the beast. I figgered as old as the bike
was, new seals couldn't hurt. Just a few bucks for them, and I had the time
to do the project. Got 'em in and everything back together okey-dokey. In my
own mind the engine seemed to start easier, but maybe it was wishful
thinking. A short test run told me otherwise. Stumbling and lurching at any
speed, and very reliable backfiring whenever I'd back off the throttle. (From
the muffler, not the carb)  The plugs are good, and the color of the deposits
on them suggest okay fuel mix, though the rear plug is slightly different
from the front plug. Resistance of the plug wires is in spec, an I have a
lovely (open air) spark for each cylinder. With both plugs installed, but
only one cylinder firing at a time, I get smooth running and nice idle for
the front cylinder, and rough running and no ability to idle without dying on
the rear cylinder. This is while running in the garage - the only load on the
engine being the compression of the non-firing cylinder.

I've got adjustable pushrods, and wondering if adjustments on the rear
cylinder are a good candidate for this problem. I have not checked this out
yet, as I will need adult supervision for this. I figured I'd check with the
collective, here, before goin' on an easter-egg hunt.

Thanks for your time.
tom k.

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I will find a way or make one.

 tom koehler wrote:

Pull the enrichener all the way out and see if it runs any better at
idle and light throttle, if you don't see an improvement/change (beyond
normal) it's probably not fuel....

 tom koehler wrote:

While the alky is good for me it's not real good for your bike. If you
think you have a bad load of fuel, dump some out into a glass container
to analyze.

Best to dump it all and burn it in the lawnmower or cage. Put fresh fuel
in it even if it's just regular (1 gal don't fill it with reg) it will
run fine on regular just not hard or hot. But you can limp it to the
good gas.

Adding stuf to a bad load of gas just gives you a larger load of bad
gas, and if it's water you want the stuff out of your tank NOW.

 On Wed, 8 Jul 2009 10:14:26 -0500, Ryder Rick wrote


Just wanted to say thank you, for taking the time to reply to my situation.
Yeah, bad gas with alcohol in it is not a first-rate solution, but it seemed
prudent at the time.
tom k.

--
I will find a way or make one.

 tom koehler wrote:

  Seemed that way to me too ...
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