Author Topic: The Mysterious Powerless Bandit?!! (Read 3200 times)

jp_bandit4 · « **on:** December 19, 2005, 01:15:18 PM »

Hi there, wonder if anyone might be able to shed some light on a problem with my bandit400 '91.

On the exit of a corner yesterday my engine suddenly slumped, lacking in power and made a more throatier sound from the exhaust. I was only doing about 30 mph with my girlfriend on the back. Now when you twist the throttle there is no real response from the engine and you have to wait for a steady build up while that noise gets worse ahhhh!!!. When idling the revs will fluctuate making its way up to 2000 and back down again by itself ???? very strange

and the irony is all last week it was being serviced and passed its mot saturday lol!

Any suggestions on this would be much appreciated
cheers John-paul

Maniac · « **Reply #1 on:** December 19, 2005, 03:42:45 PM »

Sounds like it might not be firing on all 4 cylinders. Check the plugs and make sure all of them have spark, when in doubt go ahead and replace them.

jp_bandit4 · « **Reply #2 on:** December 19, 2005, 05:37:32 PM »

thanks for your reply, yeah it seems to be the case however i dropped it off this morning at a local garage but unfortunately they cant figure out where the problem lies but they're gonna give it another go tomorrow. One of the spark plugs were wet, however the problem remained after replacing it. Could i have possibly blown a gasket or cyclinder? im guessing these sort of things can be pricey........

PitterB4 · « **Reply #3 on:** December 19, 2005, 07:38:16 PM »

Check the plug wire/boot connection on that cylinder. The B4 plug wires have a nasty habit of loosing contact with the boot. That's the easy one. The harder one is a blockage somewhere in that carb. How's the inside of your tank look? If it's rusty, that could be the culprit. A cleaning would be in order.

solman · « **Reply #4 on:** December 19, 2005, 08:23:30 PM »

Quote

One of the spark plugs were wet

Fuel wet or oily wet?

B12Teuton · « **Reply #5 on:** December 20, 2005, 08:58:22 AM »

Also check and make sure the rubber boots that connect the carbs to the intake and airbox are in good shape. At the age of your bike, it is possible one cracked and caused an air leak.

Maniac · « **Reply #6 on:** December 20, 2005, 10:25:58 AM »

You may also want to check the electrical connections to the coil, and if you have an ohm meter, check the pickup and coils themselves. A 'wet' plug indicates that the plug wasn't firing, which is consistant with the problems you've described.

Just on a whim, if you can't find anything obviously wrong (loose connections or the like) just put 4 new spark plugs in and see what happens. You may be surprised.

jp_bandit4 · « **Reply #7 on:** December 20, 2005, 01:22:44 PM »

WOOHOOO! Its fixed!

Thanks for all your help people, much appreciated.

Two wires from the battery running under the tank had aparently 'arched' and were practically touching causing a spark between the two which short the wires and meant the two cylinders werent sparking. Good news though the garage didnt charge me for it and picked it up this morning!
John-Paul

Maniac · « **Reply #8 on:** December 20, 2005, 04:49:31 PM »

Awesome!

PitterB4 · « **Reply #9 on:** December 20, 2005, 10:48:35 PM »

Sweet!