Shee wont spark, tried everything and still no spark.

[93dakman]

Hi, I have been working on a guys banshee for the past month or so on the weekends and have ran into problems every step of the way. it really was a real piece when i recieved it. THe skirts were broke off the pistons, the jugs were already on their last overbore and WAY over specs for just a ring job, the cool head had no o ring, just gasket material, the tors had been broken off, both carbs leaked about a quart a piece every minute and most every engine bolt was missing. Well I rebuilt it and cleaned a fixed everything, got it back together and went to start it, sweet, it started second kick. ran rough but a carb sync and new plugs would fix that. so i put the plugs in it and tinkered around with the carbs. I got it running and it cut out still and bogged over half throttle still then all of a sudden it backfired and died. after that I could not get any spark from it at all. I might get a week light blue spark every thirty kicks. so I got on here to learn how to disconnect the tors stuff, only two places did i change, the black box and the carb tors connectors. i went to check for spark again and i still have nothing, so i pulled the left cover off and checked the wires. then a pulled the flywheel and checked the rest of the wiring, all for proper resistance and cont. then i noticed that there was no flywheel key. anywhere. not on the magnets, on the floor or int he engine and i didnt remember hearing it drop either. I dont know what could be preventing spark. the ohms seem right for everything and the coils good.

 

also I can not figure this out, since i did not find a flywheel key, im assuming when it backfired it really through the flywheel way out of time. but what i can see is even if the flywheel is 45 degrees off, it should still make spark right? just not at the rigth time right. thank you all in advance.

[J.J.]

Welcome to the HQ!

 

I think you found the problem.

It's not going to run too well with a 45Deg timing advance/retard. More than likely it's the timing that caused the backfire.

 

You should also confirm the gap for the pick-up coil.

 

You have a shop manual?

[Bansh-eman]

it doesnt matter how much you advance it... it should still a strong spark. Alot of guys refer to the ignition on these as dumb ignitions. Both plugs fire on both strokes. The timing only has to do with making the plug spark when the piston is near TDC so you get the power stroke. It has nothing to do with if you will or will not get spark.

 

I am not all that good with electrical stuff, but I can refer you to Snopczynski. he is very good with electrical systems. My guess would be something with the coil, but like I said I'm not electrican.

[ryskie22]

Hi, I have been working on a guys banshee for the past month or so on the weekends and have ran into problems every step of the way. it really was a real piece when i recieved it. THe skirts were broke off the pistons, the jugs were already on their last overbore and WAY over specs for just a ring job, the cool head had no o ring, just gasket material, the tors had been broken off, both carbs leaked about a quart a piece every minute and most every engine bolt was missing. Well I rebuilt it and cleaned a fixed everything, got it back together and went to start it, sweet, it started second kick. ran rough but a carb sync and new plugs would fix that. so i put the plugs in it and tinkered around with the carbs. I got it running and it cut out still and bogged over half throttle still then all of a sudden it backfired and died. after that I could not get any spark from it at all. I might get a week light blue spark every thirty kicks. so I got on here to learn how to disconnect the tors stuff, only two places did i change, the black box and the carb tors connectors. i went to check for spark again and i still have nothing, so i pulled the left cover off and checked the wires. then a pulled the flywheel and checked the rest of the wiring, all for proper resistance and cont. then i noticed that there was no flywheel key. anywhere. not on the magnets, on the floor or int he engine and i didnt remember hearing it drop either. I dont know what could be preventing spark. the ohms seem right for everything and the coils good.

 

also I can not figure this out, since i did not find a flywheel key, im assuming when it backfired it really through the flywheel way out of time. but what i can see is even if the flywheel is 45 degrees off, it should still make spark right? just not at the rigth time right. thank you all in advance.

one more thing is i have ran into is that both plug wires half to have plugs in them or they will not fire so if u got one wire disconected and the other with a plug in it, it wont spark. just make sure that the wires have plugs in them and grounded. i would just leave one plug in the cylinder and the other laying on the top and kick it and see what happens. this may not be your problem but its food for thought.

[93dakman]

i do not have a shop manual because i was assuming (i know..... a** outta u and me!!) that this thing would be easy just like every other two stroke ive built. but now im running into this.

 

thats what i thought, it should still spark no matter where the flywheel is but not at the proper degree of crank rotation. I also did not know that you will not have ANY spark if you pull one plug out of the cap. what is baffling me is that if i kick till im worn the heck out, i will get one faint blue spark. this makes me want to think the cdi box went on vacation. i still cant figure out why it ran great, then backfired and quit for good, unless the cdi box just up and died and realeased all of its energy stored in the capacitors (causing it to spark at the wrong time therefore backfiring). and not a sole in this town has a banshee to swap boxes with!! ha. oh well i will get to the bottom of it.

 

i have read different posts about tors. I dont want to buy a block kit for it till i get the machine running. so far i disconnected the black box above the left pipe. Disconnected the two carb connectors and cut the wires coming out of the throttle. i do not have a parking brake. from what i understand thats all i need to do to disable the tors system.

Edited March 3, 2009 by 93dakman

[sleeper06]

Are you sure you didnt shear the key off,just buy a woodruff key and try it,check pick-up coil gap.I have had keys dissappear before on diffrent bikes that came through.I highly doubt your cdi is bad although its possible. Is your crank marked up around slot.take a pic and post it because with no key in there it would explain intermitant spark

[AKheathen]

check the black wire on your coil for good ground to both the engine and the frame, and replace the plug caps. at the cdi, check that the black wire gas good ground too, and the black/white wire has no continuity with the kill switch in run. next, shake your flywheel to see if it rattles. what kind of puller did you use to remove it?

[R. Rollins]

My sons ATV had a good CDI but bad coil that I found defective all of a sudden.

 

It did just as yours did, every now and then it would have a faint blue spark.

I replaced the coil and it ran fine.

 

 

Could this be the problem ??? is it a possibility??

 

[93dakman]

Hi every body, i just got a chance to work on this bike again. i picked up a flywheel key, had to gring on it to fit, it was the right width just too long, cleaned every connection on the bike and tested continuity and resistance on everything....EVERYTHING. there was a few problems, first off, im sure the flywheel key was number one, then the fact that i only had one plug on the bike, and one plug wire removed, then i was testing resistance through that removed wire and cap and the resistance blew WAY up, so i replaced the cap, new plugs and installed the flywheel and it started right up!!!!!! thanks every one

 

Now heres the recent problems. I have disconnected the tors system but the guy that owns it does not have enough funds to afford a tors removal kit. the two knurled screws on each tors is missing, looks like they are broke off. i have no idle adjustment so it makes it hard to start for a couple of reasons. I know the carbs are spotless because i cleaned them THOROUGHLY!! I have the filter off and to start it I have to put my hand over the air box filter opening to get it started. then it wants to bog down real fast if i dont crack the throttle, THEN when i do give it gas, it winds up REALLY high and doesnt come down very fast. Sounds like an air leak to me somewhere, Ill find out where its sucking in later, unless you think it could be the carbs some how. I jsut quit working on it tonight, its 2 am. Just an update. thanks