Motorcycle Repair: Harley Cough, harley dealership, intake leak

Question
Mike,

I have a 2000 XLH883, 8.5K miles that has just started having a bad 'cough' in the front cylinder.

Had it stored in our local Harley dealership this past winter, and it was checked out for the season there.

Getting close to the 10K, I decided to change the plugs early, and have since developed a BAD misfire in te front cylinder.  

Before riding, I allow the bike to get up to temp, heads warm/very warm, and it doesn't miss a beat while the enricher is at half.  Once I get moving or put it under load (enricher off) it bogs down and the #1 misfires badly, and I mean badly!  Loss of almost all power, have to clutch it to keep it running!  Oh, setting some enrichment, doesn't solve it at this point.

Once the engine gets hot it runs perfectly, no miss at all, but it has to be HOT.

Very annoying, and perhaps damaging.
I checked the plug, and the plug wire/clip as well as gap (.40) Oil was also changed.

That's my problem, hope you have a few avebues to explore for me.

Safe riding,

Ed


Answer
Here are a few things to check. Since it started right after changing plugs you might have gotten a bad plug. I would go ahead and change it.
Check for a intake leak. Start the bike and using some carb cleaner spray a little around the intake manifold. If the RPMs go up then you have a leak.
Another thing it could be is a bad valve, but it should be with that new of a motor and it started right after you changed plugs.
Good luck and happy riding
Let me know what you find
Mike