I have a Banshee I am having a problem with. The bike developed a low-rpm "bog". When idling (which is no longer likes to do), when you try to rev it, it acts as if the choke is on, and is boggy and doesnt rev crisp. It also will shoot a blue flame out the right side silencer. I swapped coil wires to the plugs, and have the same result. This is an indication to me that the electrical portion of the bike is ok. (If you have any ideas otherwise let me know) I have had the carbs apart twice, and no luck there. However, when the bike is good and warm the choke seems to help the bike rev correctly, and doesn't kill the bike like it normally would when the bike is hot. My guess is an air leak on the right bank. Any obvious places, that would also cause it to backfire out the exhaust? I am kinda stumped here and any help would be appreciated.

 

Check to make sure the choke tube that connects the two carbs is connected. You also might want to try to disconnect the two wires that go up to the clutch lever. If you leave the e brake on and try to rev the bike it runs really bad... it's a safety feature on the banshee. You also might need new reeds on the right side. Could also be the air screw on the right side. I really can't think of anything else right now... it's been a really long day.

 

You need to make sure that the carbs are in synch.

That sounds like the problem to me....But it could be anything from a bent/worn needle to an air leak...... Start the wheeler and mist some water artound the air boots..You will know in an instant if there is an air leak....

Look down the intake to the carbs and check the level of the slide...They should have full movement and be even on both sides.

 

OK, now here is some more info on the same subject. I messed with it for hours today. Here is what I have done. I put a new set of coils on the bike, same result. I rigged up a duraspark ignition in place of the yammy CDI, same result. Switched the carbs around, problem still on the right side. Replaced the stator, same result. I did a pressure test and a compression check and they both check out fine. The right side cylinder just isn;t firing like it should. You can put your hand in front of the exhaust on the right side and just feel air come out, except for when you put the choke on and the cylinder will start firing again. This is what I think now. The flywheel is screwed up! The reason to my thinking, is this, the coil fired on every TDC and BTDC of the piston stroke, so when on is up and fired like it should the other is down and the plug is also firing. Now, with a correct mixture of fuel and air, the mixture is not enough to light off. With a rich mixture (choke on) it fires off, although not where it should at TDC. Does this make sense? and account for the choke making a difference in performance? I'm thinking the flywheel is now non-magnetic at the area responsibl for lighting off the coil for TDC of the right side cylinder. The left side fires fine and actually keeps the bike running even with the right side wire pulled from the plug. Thanks for any info on this!!!! Later

 

may seem like a long shot, but if you've switched the carbs, the problem may be with the reeds. have they been checked? it seems unlikely that the flywheel would get itself out of whack. how old is the machine, and is it stock?

 

I guess it could be a flywheel...But I somehow doubt it.... If you have checked the reeds....and made sure your compression is about the same in each cylinder...(It could be rings on one side).

Then it could be more of an internal problem (like flywheel)

 

I have checked the reeds and see nothing visually wrong with them. They are the carbon fiber type. I really don't think it is a problem with the right side cylinder, when I rev it up fast enough it will fire, and seems to have the same power, kind of hard to tell. It's an 87 and I assume the original flywheel, and the flywheel is kind of nasty looking, looks like a bolt came loose and was getting banged around before I got it, but it ran fine for 4 months now. I just rebuilt the engine about 2 months ago, and it has maybe 15 hours on the new pistons. I had another idea about the flywheel that I am going to try when I get home today, and see if I can find something wrong with it. If it checks out, then I'll swap the reed cages left to right, I doubt that is the prob though. I can't be very far off from the problem now, nothing left to mess with. Later

 

On my 97 banshee i recently removed the parking brake line and the parking brake lever on the handle bars. When I took off the lever at the handle bars there was this button that would normally be pushed in with the lever on. When the button was out it idled but when you gave it any gas is was like the chocke was on. When the button was in It ran fine.
I dont know if this is the problem but worth a shot ??
I dont know if you have it on a 87 tho

 

Ok well, i have finally found the problem. This damn thing ran me in circles for like a week now, as you can tell by the previous posts. But anyway, I had the carbs off 3 times and cleaned them through this whole oreal, and I finally sat down and figured out exactly what port ran to which other ports. I went over the whole thing the last time and blew out two ports that i didnt really know the point of beforehand. They happened to be the pilot air feed and the main air feed, one of which or both had something lodged in them...It works fine now, but thanks for all the responses...damn carbs..lol...