Starting up my buddies banshee that i store for him for the first time this year. Started up fine (3 kicks) stays running fine, but when given throttle one of the exhaust pipes backfires (only the left side) Why? Bad plug?, Bad valve?, Bad Fuel (its from last year)? 1st & 2nd gear have almost no power and the pipe backfires, 3rd gear and up sees no power loss and no backfiring. Any ideas as to what the problem is?

 

Bad valve.[img]i/expressions/face-icon-small-wink.gif[/img]

Pilot jet is clogged. Pull that carb off and clean it. Make sure to pull the pilot and clean it very good.

 

how do your CPI's work. My buddy has the in-frames and they're sweet. However he has burned himself on them several times and there is stuff on the pipe now (burned pants + gloves) any way to get that stuff off?

 

CPI's are awesome. I have the same problem because I TT race and ride way forward on the bike. I have just switched to shearer inframes because I picked up a few HP on top vs. the CPI's.

 

I have the exact same problem as you. Mine either backfires or does not fire on one side no matter what I do. cleaned the carbs, sync'd the carbs, new gas, new plugs. The only thing I have left to do is to replace the CDI. Please let me know what you do to fix yours, mine is keeping me from riding and that pisses me off.

 

The ignition problem you are having could be caused by the resistor caps on the plugs ( the caps on the end of the coil wires)... These are resistor caps and have been known to cause ignition probems... I took my stock caps off and threw em in the trash.... I replaced them with (NGK 0 resistance 14mm plug caps) ( NGK part#LBER ) And I run ( NGK BR9ES resistor plugs )....

 

Are you saying to replace the top cap of the plug or the plug wire where it connects to the plug itself? I have never thought about replacing the plug wire and did not know it could be a problem. I thought that I would have to replace the CDI to replace the plug wire. Here is some more info to fill you in to date. Sounds like you are a long time Banshee owner. This problem has been going on since I have had the bike. 6 or 8 years. It is why the guy sold it to me cheap in the first place. Anyway, the first thing I did was clean, sync, new plugs and try new jets. didn't work. Then I put on a single 34PJ. still doesn't fire in both cylinders all the time and pops and spits out of one when it does fire. I then put on a 2into1 exhaust and just rode it that way. It would run and keep up with LT250's and 250R's but was not impressive. Obviously, I would constantly foul plugs in one side. But I could tell when both cylinders were firing, it would run better, but only for a while. I then pulled the motor and bored, pistons, rings, thinking this would fix it. No better. Now I can't seem to keep up with well tuned 250's. So I put the stock carbs and exhaust back on and am trying to fix my problem and this is where I am. Is there a test for the CDI? Does this sound like the right direction to go in. Can't take it to the dealer. too much pride. need help

 

Don't take it to the dealer,they charge too much.After all you've done,The cdi and plug wires is about all it can be I think.Call around for prices.The dealers will probably charge too much.
Hey AlkyburninX could you tell much difference when you switched pipes?

 

My 96 Banshee did that when it had a bad spark plug in one of the cylinders.
Another prob could be the old gas, or a jetting issue.

Start with the simple things first
1) Gas
2) spakplug
3) Clean the carb/re-jet if necessary

4) Do a plug check at WOT to check the main jet, and 1/2 throttle to check the needle settings.

 

Speed005, yes the plug on the end of the wire.... You can get the parts I mentioned at (www.sudco.com).... Use the part#'s in my previous post...... If you change to 0 resistance caps , make sure you run resistor plugs...... Like the one's I mentioned.....[img]i/expressions/face-icon-small-smile.gif[/img]