banshee cylinder not firing?

[joeeyyy]

pevious problem with my banshee was at this stage:

just recently had a trip to buttercup dunes(imperial sand dunes) and my banshee had two good runs up the hill and ran fine in the bowls then all of a suddenly the bike began to bog in second alot while in the bowls and it wouldn't run the hill either it would shift into first and second and would bog out in third half way up the hill, this bike usually could pull 3rd and 4th up the hill before but all of a sudden the powerband was gone in third and it bogged in second in the bowels, where do i start i just had it dynoed it was 55hp. had it jetted for the dunes the only thing i changed was my gas and oil mixture i went from 50:1 vp c12 with power plus to trick 40:1 with benol would this have effect my powerband and cause it to bogg?

now my problem is:

cleaned out the carbs and went back to my old mixture with gas and oil(vp and powerplus) but their is still no power and one pipe smokes quite a bit more than the other and that cylinder and pipe do not get hot when the bike is running, i tried opening it up down the street and as soon i slowed it would die and have trouble kicking back on, after riding it for about 7 min. i pulled the plugs and one was turning a light brown and the other was brand new looking as it was when i took it out of the box(it came from the side that was smoking alot and not heating up) the only things that i have touched was the gas and oil types and mixtures but i returned those to original, i also fooled with the the air/fuel mixture screw a bit but would that cause this much of a problem? what does it sound like to you? where do i start? also i checked the reeds they were fine

[FIRST BANSHEE]

I would first check for spark. If there's no spark on one cylinder, try disconnecting the thors system, throttle switch, and parking brake switch if equipped. If all that stuff is already removed, your stator my be weak. did you try switching spark plug wires from side to side to see if the other side fires.

 

welcome

[ssanddemon]

Joey, I saw your post on another board while looking for info on why mine is screwing up. No reply from those loozers , so at least I guess we finally found a good home here! Mine has almost exactly the same problem: Runs great on the right side, little or nothing on the left. Initially, the problem was an intake leak from a damaged/defective grommet sealing the ProFlow boost bottle to the intake. As I have had this problem before, I have removed the boost bottle and gone back to the factory balance tube, modified to fit the ProFlow intake. After that minor repair however, I ended up with the dead cylinder problem. I swapped from side to side the: carbs, spark plug wires and reeds; no change. With new plugs, the left cyl. would fire properly for a few seconds then start cutting out again . Plug would foul, with some smoke from the exhaust but no actual combustion. I have completely torn down the carbs (with which I am very familiar due to jetting changes after every mod), and found no problems. I removed ALL jets, cleaned with carbkleen and compressed air, and installed new needle/ seat assys. Compression test showed 125 (L), 115® after 10 kicks, and about 150 psi max (both) with 20 kicks. My riding buddies are all professional mechanics like me (heavy equipment and automotive, not ATV/motorcycle) and we are pretty savvy. None of the guys could figure out what the deal is. Finally, I have torn down the top end and found some minor erosion of the piston crown on the left side, right looks perfect. Cylinders look great with no scoring. I am assuming that since I have not always run a race gas mix with my .080 shaved head, and the possibility of a lean mixture on the left side due to an intake leak that I have had some detonation issues finally cause damage to the piston/ ring's ability to properly seal the combustion chamber. I will be installing forged pistons with high quality rings in the very near future, and will post with the results.