I have an 89 FLSTC and when I ride it cuts out. If I stay on the gas it cuts back in. It did it to me a few times during the season. Then I ran it for about a month with no problem, and now it did it to me again today. It cut out on me 3 times during my ride and then it cut out altogether on me when I was on the highway. I tried starting the bike for about 3 minutes before it finally started up. Then it ran fine all the way home, about 10 minutes. Any ideas what the problem could be?

 

Had this problem awhile back, turned out to be the neg. bolt for the battery had begun to backout. Just something you might want to check.

 

probably plugs, wires, or coil

 

Check the battery connections first (easiest to do). Next place I would look at is fuel delivery: How old is the gas filter? Unhook the gas line, and run the hose into something while cranking the engine over or just watch carb in action (running bike) by checking accelerater pump operation: squirting a shot on demand or does it peter out? Diaphram operation OK? Reversion (farts)? Carb float bowl and valve and the "Annual Cleaning of the Jets" would be a good finish up.

 

This happened to me, turned out it was a grounding issue. A factory defect on my 03 FXST. Make sure all your grounding wires are bolted nice and tight.
Left me stranded a few times. But haven't had any problems since... *knock on wood*

 

Do you wash your bike before you go riding?

I tell ya. This is a weird one and I still don't have it fully figured out. I washed my bike one Saturday and in doing so I removed the seat and fender bib as not to have wet pants the rest of the day. I didn't cover anything with plastic as I never sprayed directly into that area.

Wife and I decided to take a ride few hours later. As were going down the road sometimes when I would hit a bump it would cut out... just for a second. Didn't do it every bump either. Finally on the way back in to home about 5 miles from my house I hit a bump and it completely died. I had power but no power to the starter or fuel pump. I had a buddy come and we loaded it up in the trailer and I didn't get to it till the next day.

Now the only thing I could figure was that maybe... just maybe I pinched the kill switch wire when I put my new bars on and ran the wiring thru the bars. Probably just now wore thru or so. I was checking the fuses and came across a blown 15amp. Replaced it and it started up. Now it hasn't done it again... as of to date. After talking it over with a couple of buddies we thought maybe water got down in the fuse block and bumps were knocking beads down in there further eventually to where it ground enough to blow the fuse. Other than that though I really don't know. Figured if it was the handlbar wiring it would still do it. I have intentionally taken it out and hit bumps... nothing. My next plan is to see if water got in the bars and still my first theory is correct by washing it (this time with plastic covering the electricals under the seat).

Just a thought and a story I had to share.