Sorry if this is a repeat quesion, i couldnt find much going through previous threads. I also copied and pasted this thread from the sportster section hoping for another response.

I have had my 93 sporty for a year now, it has never had any problems starting, it would usually fire about 2 revolutions of the motor. I took the bike this past fall on about a 300 mile round trip, about halfway, i checked the exhaust coming out of both pipes, rear jug was hot... front jug was cold. I snagged some plugs from one of my buddies riding with me and swapped em out and started the bike, it ran fine, however the front jug was still cooler, firing atleast but wasnt ice cold like before. Enough to get me home.

I first changed out the coil with an oem, new plugs, wires. The bike ran 100x better. After a short trip around the block i parked the bike. The next day when i tried to start it, it acted like it was flooded, I let it set and tried again. Wouldnt start, pulled the plugs, blew the fuel out of the cylinders and no luck. The best i could get out of the bike was a couple backfires.

Since then i have stripped the bike down, traced every single wire out to make sure of no breaks, cuts, scrapes or grounds. Checked all the fuses, pulled the fuses out and rechecked them again. Replaced the coil, wires and plugs again with oem, replaced the ignition coil with a SE(because OEM was so far backorderd.) And still i have yet to get the bike to run. I pulled the plug wires and just placed the boots over the top of the plugs so they have to arc to fire, and when i do that, i can get the bike to either backfire like a shotgun(and always from the rear jug, never the front) or it will try to fire and might run half-arsed for about 3 or 4 revolutions. It actually sounds like its trying to fire at the start of the exaust stroke on the rear cylinder.

I didnt do anything for the new SE ignition module but plug it in, i dont think it has to be "programmed" since its not fuel injected.

The 2 things i havent replaced is the battery(it does the same thing if i use a charger so it dont drain the battery) and the timing sensor behind the timing cover(which the timing plate has not been moved or adjusted since when it was running perfectly)

One of the things i didnt mess with was the V.O.E.S., the vacuum operated switch that advances and retards the timing slightly according to the load of the bike. I am pretty sure (not positive) that regardless, when the bike is not running the timing is retarded as far as possible, easing the inital start. All of the research i have done about it, nothing has mentioned that switch though.

Push starting it didnt work either, nothing but a few backfires.


I'm at my wits end here, i have about a month to ride, and then i deploy to the Persian Gulf for 6 months. If someone has an idea of what could be causing this, please by all means help, as the local Harley shop and custom shops in the area have yet help, all telling me to do/try something i have already done.

 

No one has a clue either huh?

 

An engine needs 3 things to run. Fuel, timed ignition and compression. From your post, it sounds like you have fuel but you may have too much fuel. It would be the last thing I check. Compression would be the first. Have you done a compression check? That can reveal mechanical problems suck valve issues, cam timing issues, rings etc... Check compression. Assuming you have good compression and fuel, the ignition would be where the problem is. The module would of been my first guess. You changed the module and checked the wiring, so that is most likely not it. Next would of been to test the coil. You said you changed it also, so I suspect the coil isn't the problem. I am not sure I understood you in the spark test, but I would put new plugs in the boots and ground the threads to the engine. Then turn it over and watch for strong Blue sparks. They should be very consistent. If not, you have some ignition issue. You mentioned the cam sensor was not replaced. The cam sensor is a pretty simple device, I would guess that if you have spark as suggested, the sensor isn't bad. If the spark isn't consistent, I might try changing it. I would think if you follow these tests, you should have an answer to what the problem is.

The hard part is not being able to see, touch and listen to the bike. Hard to solve the issue from a keyboard. If you get no where take it to a shop. There is not rocket science involved, someone can find the problem.

Good luck

 

double post, sry

 

I recently did a head job on the bike, lower cylinder gasket was leaking so i replaced all the gaskets from the crankcase up, new rings, the works. So i ruled out the compression test, as all i do is rebuild recipricating air conditiong plants and was pretty confident in my new rings being in right and not cracked.

So anyway, i go out to the garage to smoke and decide to "try" and start the bike for a laugh... it turned over twice and was running, i damn near jumped out of my socks. The thing hadnt run since november. I quickly started retracing my steps of what the last few things i did to the thing. I was messing with the harness under the seat, pushing, pulling, moving stuff around. Reluctantly i shut the bike off (scared it would never start back up hehe) and started pulling harness plugs. I found a pin loose inside of one of the plastic harness plugs, something i had to of overlooked.

Thanks to those that took the time to read my issues with my sled. It was greatly appreciated.
Catch you guys on the road.