free website stats program Could this be a coil problem? | Page 2 | Harley Davidson Forums

Could this be a coil problem?

I'll drain the tanks tomorrow. I'm out of commission anyway since I pulled the rear wheel to add some polished stainless rotors, pads and to clean a few years worth of road grime from everything. Glad I did, it cleaned up nice, but the rotors didn't come in so I've got the weekend to chase down this problem. I briefly looked at the intake ant I think it could be leaking, and my rear rocker gasket (I think that's what it's called. Upper gasket on rear cylinder.) is leaking.
 
Changing out the intake gaskets and the upper rocker gaskets isn't too much trouble. If your taking the tanks off to drain and flush them then I would do the gasket work while you have the tanks off.
 
Thanks to everyone who responded. It looks like glider and heritage had it right. My intake was missing a bolt and I could move it up and down. The rear jug was black from backfire. New gaskets and bolts, and it's rock solid.

I picked up a whole new set of tin with fresh paint at a garage sale for an unbelievable price, so the tanks are coming off tomorrow. I geuss I got more work to do with the rocker gasket, but it only makes sense to do it now. Man, this is torture. I'm burnin' summer, but it's going to be a whole new bike when I get back on the road.
 
Thanks to everyone who responded. It looks like glider and heritage had it right. My intake was missing a bolt and I could move it up and down. The rear jug was black from backfire. New gaskets and bolts, and it's rock solid.

I picked up a whole new set of tin with fresh paint at a garage sale for an unbelievable price, so the tanks are coming off tomorrow. I geuss I got more work to do with the rocker gasket, but it only makes sense to do it now. Man, this is torture. I'm burnin' summer, but it's going to be a whole new bike when I get back on the road.

Glad you located the problem and got it fixed.
 
The problem lives on! I replaced my intake manifold gaskets and bolts and cleaned out the tanks. I didn't get the rocker gasket replaced yet, but can't believe that would cause this problem.

I was on my way home yesterday and while I was sitting at a light I felt a lot of heat coming from the rear cylinder. It happened fast. By the time the light turned green, I had dropped the rear cylinder. I stopped for about 15 minutes and the problem went away. I didn't have a plug wrench to check for spark, and I haven't replaced the coil yet. I'm going to get one at lunch. I'm going to do the plug wires and plugs at the same time.

I was planning my first long ride tomorrow night, but now I'm considering trailering it. This problem is very inconsistent. It's only happened twice now, once on a hot day with the wife, and once on a not so hot day when I was alone. I'm still glad I did the intake work, it had to be done, but my question is, does anyone believe a leaky rocker gasket could cause this problem, or like me, do you believe it's the coil? Also, what is the gasket below the rocker gasket on the cylinder called and is it a lot more work to replace since I'm going almost that deep anyway?
 
From what you say,it still sounds like an intake leak when it comes on like that. Lean is hot also. Key is to find out if you have spark when this happens. Check the spark plug tip where the wire attaches to see if it is tight and the plug wire fully on the plug.

I highly doubt the gasket is causing the problem here.
 
It wasn't the coil. I replaced it and still have the problem. It's happening more now with less time in between each episode. I would say that in addition to a leaky rear rocker gasket, I've got a blown head gasket (99% sure). The oil from the rocker made it hard to tell. The rear plug is white from running so hot.

Now, is this the way the bike would act with a blown head gasket? Would the head gasket have caused the cylinder to get hot (could it be sucking air through there?) or did the hot running cylinder cause the head gasket leak? I'm getting closer.
 
I meant to check compression last night and didn't. I was just going to see if there was a difference between the two cylinders. Wasn't sure if the compression would drop only when the problem is happening, or if it would be lower in the rear all the time. I want to know just to be sure, but I'm already sure I'm losing power just before it shuts down. The bike also starts running so rough that my eyeballs vibrate before shutdown.

I'm giving up. I'm headed out of town and don't have the time to fix it myself, and since it's already on the trailer, I'm dropping it off at the shop tomorrow morning. It'll be done when I get back and my wallet will be easier to carry around with all that money taken out. I'll report the outcome.
 
A quick test to check for leaking head and intake gaskets is to spray a little carb cleaner around the joints while its running, if it stalls or sputters when you spray a gasket area that's a good indication that its leaking.
 
Back
Top