Left cylinder dead

[Dwayne_Collins]

I have a 1998 Banshee (basically stock). When I bought it in 1999, it came with Toomey pipes, boost bottle, proflow airbox, and probably the carb jets required for the Toomey pipes. It ran flawless for 3 yrs. FYI, I have just enough mechanical knowledge to make me dangerous. Approximately 3-4 yrs ago, the cyliner on the left side died. At that time, I pulled the motor and replaced both pistons, rings, and gaskets. I broke in the new top-end slowly over a 2-3 day period (running fine/both cylinders working properly). My son then took it for a more aggressive ride and the left cylinder dropped again. Needless to say, the Banshee has been sitting on a jack stand with a cover on it in the barn for the last 3 yrs. My son came up yesterday and we attempted to get it running. We changed oil, new gas, new sparkplugs. Started on the second kick. As expected, the only cylinder working is the right side. With a little throttle, the right exhaust is warm, the left exhaust blows out raw fuel !!! We checked the spark and both sides and both are sparking well. We removed the airbox to inspect the carbs. Trottle timing was indentical. We removed the reeds and did not see any cracks/chips. I do not have a way to check compression, but when I put my finger over the sparkplug hole, both sides feel equal. With it running, I removed the radiator cap to see if maybe the radiator fluid would flucuate with increased throttle, but it did not. Needless to say, I put it back together and once again it is sitting back in the barn.

 

I was told maybe the stators were bad. I was under the impression, if both plugs were sparking well the stator was functioning appropriately. Again, I'm not a mechanic. I was also told may the electrical component located under the seat could cause similar problems. I'm at a loss. All I can say is for some reason the gas is not being ingnited in the left cylider and basically blowed out the left exhaust.

 

Has anyone else had this problem? Any help and suggestions would be greatly appreciated.

 

Dwayne

[TwistedSheeRida]

Have you taken the carbs apart and cleaned them out and checked the float height. Sounds like the float is getting stuck on the left carb. But you should get a compression tester just to check out the motor also.

[fastquad02blaster]

Have you taken the carbs apart and cleaned them out and checked the float height. Sounds like the float is getting stuck on the left carb. But you should get a compression tester just to check out the motor also.

If you have fuel and spark, the only other thing missing from the equation is compression. Plus 1 on the compression test. You might have a vacuum leak on that side and running lean and melted your piston.

[Dwayne_Collins]

Have you taken the carbs apart and cleaned them out and checked the float height. Sounds like the float is getting stuck on the left carb. But you should get a compression tester just to check out the motor also.

 

Thanks for the info. Will check carb floats. What should normal compression be?

[Cali]

Any gas on the spark plug?Could be a dirty jet..Also what about the Tors?Did you try unpluging the wires that go to the black tors box under the tank?

[mxwild74]

I have a 1998 Banshee (basically stock). When I bought it in 1999, it came with Toomey pipes, boost bottle, proflow airbox, and probably the carb jets required for the Toomey pipes. It ran flawless for 3 yrs. FYI, I have just enough mechanical knowledge to make me dangerous. Approximately 3-4 yrs ago, the cyliner on the left side died. At that time, I pulled the motor and replaced both pistons, rings, and gaskets. I broke in the new top-end slowly over a 2-3 day period (running fine/both cylinders working properly). My son then took it for a more aggressive ride and the left cylinder dropped again. Needless to say, the Banshee has been sitting on a jack stand with a cover on it in the barn for the last 3 yrs. My son came up yesterday and we attempted to get it running. We changed oil, new gas, new sparkplugs. Started on the second kick. As expected, the only cylinder working is the right side. With a little throttle, the right exhaust is warm, the left exhaust blows out raw fuel !!! We checked the spark and both sides and both are sparking well. We removed the airbox to inspect the carbs. Trottle timing was indentical. We removed the reeds and did not see any cracks/chips. I do not have a way to check compression, but when I put my finger over the sparkplug hole, both sides feel equal. With it running, I removed the radiator cap to see if maybe the radiator fluid would flucuate with increased throttle, but it did not. Needless to say, I put it back together and once again it is sitting back in the barn.

 

I was told maybe the stators were bad. I was under the impression, if both plugs were sparking well the stator was functioning appropriately. Again, I'm not a mechanic. I was also told may the electrical component located under the seat could cause similar problems. I'm at a loss. All I can say is for some reason the gas is not being ingnited in the left cylider and basically blowed out the left exhaust.

 

Has anyone else had this problem? Any help and suggestions would be greatly appreciated.

 

Dwayne

 

I have almost the same identical problem, same side and all, mine had good compression on one side but the other is crap when it is running, and the pipe on the bad side when taken off has quite a bit of fluid in it and mine is runnin on the lean side as it has 200 mains and i need to be at 300s i think as the only mods to mine are dynoport drag pipes and right now pod filters and carbon fiber reeds in stock cages with stock 28mm carbs with tors removed so im at a loss as well. I can tell its not hitting on that side like it should be due to the ping of the pipe and the fact it and the head dont warm up at all compared to the other side. So im going to put new rings and head gaskets in and see what the heck that does lemme know if you come up with something different as my spark is great on both my plugs as well.

[Dwayne_Collins]

Any gas on the spark plug?Could be a dirty jet..Also what about the Tors?Did you try unpluging the wires that go to the black tors box under the tank?

 

There was gas on the plug (not dripping wet). One thing I noticed is when the sparkplug is just finger tight, there is gas bubbling around the plug while running on the left side only). Therefore I know its making some compression. I don't guess I know anything about the Tors? I'm going to have to read about what it does. Thanks for your reply