Hey guys, had a spark issue thread I put up awhile back. Figured that out (CDI being the culprit) Now that the bike runs again, it runs like crap! It will fire right up and idle smooth, but 1/4 throttle it runs terrible. Hiccups, coughs, backfires, misses, whatever you want to call it all. I can play with the throttle and get it to rev out, and if you hold it at 1/2 or better throttle it runs fine. Unless your riding it, it cuts out alittle bit.

Took a picture of the plugs ( Front is the lighter one, rear is the one that looks like its extra rich).

Also took a video of the bikes symptoms.

From what I read online so far, it sounds like a vacuum leak somewhere is causing the front cylinder to run lean (previous owner may have adjusted to run richer to compensate which is why the rear is different... does that sound right?) I dont know how the cylinders could be burning differently.

I sprayed brake clean around every joint on the carb, intake Y, to the heads etc.. no change in Idle while running and spraying...

Pulling my teeth out, i cleaned the carb twice, put new packing kit in the A/F screw, adjust it accordingly, made sure the pilot (45) was clean and its passage too, everything seems to work in the carb its just that 1/4 throttle hesitation (which I know is pilot circuit/A-F screw)

https://www.youtube.com/watch?v=rI4I...ature=youtu.be

 

Quote from your other post...seems the problem really started when you "wired in" the sportster module. Did it not plug in? If you don't have the voes wired correctly, it could retard the timing, all the time and make it run like crap

 

Sounds like the carburetor is outta tune. What jets? Baselined it recently? I didn't see you push the enrichener down. Was it already warmed up? Don't throw parts at it, yet.
I sincerely like to prove everything, starting with the stupid **** first. Fill tank, close petcock remove gas supply from carb and get a bottle to catch gasoline. Did it pour out rapidly? Is it as clean as can be, debris?
I have more time than money.
Good luck,
Tom

 

When I had a bad wire in the pickup in the nosecone I swore it was a carb issue. Had an indy fix mine so not much help but somewhere to look. Mine would idle and run hard but break up in the middle.

 

J440 I have a couple stock 7 pin ignition modules.
If you want one I can send one to you.

 

Check the carb to intake manifold gaskets a leaking gasket might cause the hiccup. Mine were shot after replacing and a little tlc to the carb it was a different animal. Just my 2 cents easy check with a spray while running easy to rule out a problem.

 

Dual fire or single on the ignition. If it's a dual flip the wires at the coil and run it a while. 15- 20 miles. Then check the plugs to see if the lean plug turned rich.if it did it's the wire if not it's not in the ignition and I would start with a compression test. If it's a single fire ignition you can switch the 2 outer wires on the coil then switch the plug wires and again ride and check. Again if no changes, start with a compression test.

 

Are you running the bike with the enrichener pulled out, or is it all the way in?

 

I start it on choke but it runs rough, turn it off and it idles like in the video. Before all these issues it would run fine on choke just alittle quicker, and then turn it off to a smooth idle.

Stock ignition so thats a dual fire, ill try what you suggested.

I have a VOES off my sportster that was removed, Ill try wiring that in and see what happens. It just doesnt seem right because its only when i hold it like 1/4 throttle. It wouldnt run fine 1/2 and better if it didnt work.

Im begining to think maybe timing, or the something to do with that sensor plate. Mine appears fine but who knows... Running out of options here

EDIT, i forgot to mention i tried my friends stock ignition off his 96 EVO that runs just fine, no change at all

 

It was doing all of this before I put the CDI in. It just lost spark too, so the module fixed the spark, but not these other symptoms