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Rear Cylinder Plug Fouling

I see no mention of spark plug wires being tested.
They need to have a specific resistance and come with radio suppression.

I did research on the net and it was suggested that the cylinder be remapped.
I'm not sure if this applies to this bike.

My 2 cents worth
 
I did a resistance check on the plug wires, even though they were new out of the box, when I got them and they met the resistance readings in the manual. The wires were the Harley Screaming Eagle wires. Thanks. Will be rechecking spark and a few other things in just a bit.

Cylinder remapped?
 
I just went out and did a plug spark check on each cylinder in the garage, lites out. Good blue spark, looked the same on both cylinders/plugs.
 
Does anyone know if the MAP sensor on the intake has an o-ring under it for the sensor into the intake? Just thinking maybe getting an air leak there leaning out the front cylinder and more fuel going to rear cylinder. I can't find any thing in the manual or at Bike Bandit. The schematic at Bike Bandit does show a hole into the intake for the sensor. I'll try a shot of WD on it tomorrow when I get the bike back together and running.
 
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When you pulled the rear plug, was the threads on the plug clean or sooty.

If black or sooty would that not indicate some sort leakage ??
 
Gary12850 said:
Get a gremlin bell...I'm outta options
Click to expand...
About the only thing I didn't try on my '99 FXDX

She used to foul plugs (black soot) but only happened when the outside temperature was below freezing.

Tried:
New battery, coil, leads, plugs (including hotter plugs), jets, exhaust, warming with a hairdryer before I started, and various other rituals!

Solution: Traded the bike!
 
dangerdan said:
When you pulled the rear plug, was the threads on the plug clean or sooty.

If black or sooty would that not indicate some sort leakage ??
Click to expand...

No, the threads are not all sooty. The plug tightens good and is pretty snug going in and out. Thanks though....

Whiterider, the problem is with the bike in both hot and cold weather. I'd rather not pass on the problem to someone else.
 
Shifter said:
Well, I picked up my 2000 Fatboy earlier this year and have pretty much been plagued with the rear cylinder plug fouling out to the point of the bike becoming unrideable within @ 100 miles of operation. I've been through the carb and cleaned it out, along with the tank (had it cleaned out at an Indy shop due to rust). Slow jet is a 45, mid is 2 clips up and main is an 185. Added an in-line fuel filter. Ran, same problem... Had the Indy shop check out and set the carb with their computer/analyzer. Ran, same problem... pulled intake and checked seals, no problem, replaced, of course, same problem. I pulled a compression check today and both cylinders checked at @ 90 initial and went up to @ 145 psi. Went ahead and checked with a shot of oil to each and the pressures were about the same. The rear cylinder does have light black smoke on start-up and smokes light black smoke when I hit the throttle. The front plug is relatively clean with little color change. Black on rear plug is sooty, not oily. I'm at the point of thinking the valve seals are gone...The bike only has @ 10, 000 miles on it. Ideas?
Click to expand...

Sorry to be so slow weighing in on this. I am assuming a '00 Fatboy TC with Keihin CV 40mm carb, right?

If yes, have you exposed the idle-air mixture screw so that you can tweak that? Have you tried Glider's suggestion of looking for an intake leak (WD40 test)? What combinations of jets have you tried? When you had the float bowl off and the jets out, did you blow out the orifices with carb cleaner spray? How long does it take (miles) for the rear plug to foul?

TQ
 
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