www.vci.net/bash-web-design/banshee1.wav

I have uploaded a sound file of me taking my banshee through the rev range. I did it at a steady pace and didn't let off until it really wound up, then I would back off a bit. It is running very poorly. As mentioned in an earlier post, I have LRD Pipes and Jet kit. The jets are 290s and 30s.

Does hearing it help identify the problem?

Thanks!

 

Yo that sound file sounds really bad sounbds like u blew 1 pistions and the bike is running on the other pistion. do a compression check.

 

sounded like a banshee at first and then a blaster. check the spark plugs too. (just hoping for a simple fix)

 

How did you get that thing even started? the plug (one) sounds so bad it probly wouldnt run.

 

That's the crazy thing, it starts right up and idles fine. Everything just goes to crap once it starts to rev.

Also, it doesn't repeat the same always. I took it to a local guy to listen to and when I revved it up, it just broke up a little, but when I ride it, it just loses power right as you get into the part of the powerband that should be making good power.

 

I just listened to your sound file it sounds like one of your pistons has a hole in the top of it OR it could be that one of your pistons has a ring (s) that is sticking in the groves of the piston causing excessive blow buy and compression loose in one cyl. Like the other guy said in the previous post do a compression test and that should be a dead give away if there is a internal problem

 

I just did a PSI check and both cylinders are right at 120lbs. with the stock heads.

I tried putting in 240s just to see if it made a difference, but it was breaking up as well. It acts as if there is a rev limiter on it, but is higher than than the 2000 rpm that someone said is caused by parking brake.

Also worth mentioning possibly. My key switch no longer works. I took it off and tested the switch. When on, it has a closed loop. When off, it is open. The four wheeler will run with the key disconnected. It will also run with the plug jumpered so that it should be a closed loop bypassing the key switch. Could this be related?

Thanks,
Scott

 

I don't know the specs on compression for a Banshee but 120psi does seem on the low side. On my 250R, stock comp is approx 170. When was the last time you put new pistons in? How fresh is the fuel in the tank? Have you checked your plugs to see if both sides are burning the same? Are you sure that both sides are firing all the time? One more thing on the pistons if you have the stock pistons with a lot of miles on them, the rings could be so worn that you are just bearly building enough compression to run the motor at idle. But I don't know what the compression should be in a Banshee. Watch your exhaust the next time you run the engine you should at least be able to tell which cyl. has the problem by looking at the tail pipes (conistant flow or sputtering) excessive smoke or a spark plug mis fire. Hope this helps.

 

I think you have an ignition problem . Do you have a timing light ? If so hook it up and observe the flywheel as the engine runs .
See if the nasty sound you hear coincides with an erratic timing light pattern . I doubt the coil is as fault , I suspect the CDI box , or stator . Let me know what you find .

 

Sanddraggin,

I think that the stock compression on a banshee is right at 120lbs. The pistons and rings have less than 20 hrs on them.

I feel that it is some kind of ignition problem, just not sure what. To use the timing light, I just take the clutch side cover off and make a mark in order to view it with the timing light?
I figured it'd be so fast by the time it starts doing it that it'd be hard to tell when it missed some.

I guess I need to trace the wires coming from the key switch since it definitely has a problem. When unplugged from the connector, it should have changed something when I left it as a open circuit or jumped it closing the circuit. Does anyone know if this problem would most likely be the coil, cdi, or stator?

I'll get back with more info after I try finding out where the key switch line makes a connection.