I give up, what the hell is wrong with my bike?

[guitar man]

My '99 sportster has been giving me fits, it just seems to run when it wants to. When it doesn't, it seems to be starving for fuel. there is no rhyme or reason as to when it will run and when it will quit, when it will start and when it won't. I thought at first it miht be scaling inside the tank, but after cleaning the tank it still has the problem. A friend suggested the fuel tank vent was clogged, but cracking the cap open when it starts crapping out does no good. I've pulled the carb a couple times and went over it with a fine tooth comb and can't find anything wrong.

I'm at my wit's end, if anybody has any ideas, I's sure appreciate it.

thanks

[Robb]

1. I'll go with the obvious

...Just because it's the obvious I always miss. Sounds like you've chased the fuel...is it getting enough air? :shrug:

[guitar man]

2. yeah

As far as I can tell it is, the butterfly is opening and the CV slide is operating correctly.

[Robb]

3. OK, obvious #2:

...Loose battery connection? I know, I know, but check. Happened to me and I swore up and down it was a fuel problem, because I could almost keep the engine running with higher revs.

[guitar man]

4. thanks

I'll check it. Sometimes when it starts acting up I'd swear the low speed circuit in the carb isn't working but the high speed is, so it can't hurt to look.

[guitar man]

8. thanks Robb

thanks for re-directing my thinking on this one :thumbsup:

[flamin lib]

5. Try tracing the entire fuel route from tank to carb. Obviously there is

the strainer inside the tank--you've checked that--next some bikes have a shut off valve either manual or vacuum controlled (mine is vacuum). That valves allow fuel to gravity feed to the rest of the system when the engine is running but shuts it off when no vacuum is applied. If you have such it may be sticking intermittently.

The starting has me puzzled. If it were starved for fuel through a filter or valve malfunction it should start from the fuel in the line and carb. Won't run long, but it should start reliably.

You might want to check the electrical and ignition system for high resistance connections. A really strange thing happens to un-like metal connections when they corrode; they may intermittently go very high resistance acting almost like a switch. It could also be a coil defect killing the spark intensity. Bad coils often act like fuel problems.

Maddening. isn't it.

[guitar man]

7. Bingo!!

High resistance in the negative connection to the coil. Thanks to Robb mentioning the battery connections I stopped looking at the fuel system and started looking elsewhere. The negative side wire to the coil was bent at a 90 degree angle right where the wire goes into the little boot connector. I straightened it out and jiggled it around and the bike started. I could see where it had been arcing and burning right next to the boot so I skinned the wire and put a new connector on it and rode it all over the place last night, not a hint of a problem.

It sure acted like a fuel problem though, when it would die at a stop light, I could pump the hell out of the throttle and it would start up again. It was really misleading.

[zabet]

6. Check the tech section

of this forum... http://hdforums.com/
A wealth of info for the Harley owner. They have saved my butt several times! :D

[guitar man]

9. thanks

I'm bookmarking that site :thumbsup:

[zabet]

10. If you see

'ystryr'....that's me. :hi:

[guitar man]

11. ok

I'll have to sign up over there when I get time :hi:

[david13]

12. I guess they have already steered you to the hd forums, there

are more than one. Also Motorcycle Forum is a good one for Harleys, and all brands. With some good technical support.
That way you will find riders with the exact same bike.
dc