J-Bird487

well i just replaced my front coil on my 2000 superhawk and now the back isnt firing. but if i pull the plug wire off the rear, IT RUNS GREAT!!! no back firing or anything, great throtle response and everything. How can it run so good on just one cylinder??? i can even put it in gear and hold the front break and just smoke the tire!! but how on just the front cylinder???
and it sounds dumb but how do these bikes fire? at the same time or every other time like a harley does. do the front and rear fire at the same time? Thanks

L8RGYZ

Geez...that's weird.

I know it's not symetrical... I think they fire 270 deg. apart. Not sure if that means they fire @ 90 & 270 or not though, as I'm not the mechanical whiz.

J-Bird487

is there something that could be frying my coils? i replaced the brain box and the cdi already.

dustinwild

Check your regulator. I know it doesn't sound related, but mine went, and it fried my coil because of the high voltage getting through. If your CDI was pooched it wouldn't run.

J-Bird487

thanks dustinwild for the input. i tested the voltage to the battery and it reads a constant 13.8 volts through out the entire rev. its weird because if you heard it idleing, you wouldnt know that it is only runing on one cylinder. and another weird thing was that i used the rear coil to test the front one and it worked then. (the rear) and then when i replace the front, the rear one goes bad.

hawxter996

still think you have carb probs.

what is it doing to make you think only one cylinder is firing?

loserbaby

I'm Game...

re-install the rear plug lead and disconnect the front... does it run?

Then try replacing the coil you "thought" was good with the one you thought was bad... Does it run?

How are you determining which cyl is cold? You can use your hand, but it gets hot fast if it fires at all, so use a cheapo screw driver(plastic) handle and touch your header near the cyl. The cols cyl will not melt the handle as fast and will feel sticky as you drag it around, it's pretty obvious. Don't melt too much, you will have smell it as it burns off.

If your still stumped, plugs are next, but really you should swap them as soon as you determine which cyl is actually cool.

then reply.

Blam

J-Bird487

Hawxter996 my rear coil dont fire a lick. but before i installed a new coil on the front cyl, it was working fine.

J-Bird487

loserbaby i am testing the coils by swaping them with the one coil that works like say the front is working and the back dont, i swap the back with the front. and as far as grabing the rear headpipe, i already did that. lol not hot at all. i have a plug tester that you plug in the plug boot and then ground it to the motor and the rear is just dead. i think i am going to go ahead and buy a regulator like dustinwild suggusted to do. I had a friend with a gsxr-600 that his regulator went crazy and he had to replace the brain, 2 injectors, a coil and a set of gauges. i am going to try that just to be safe. by the time i get done ill have a hole new electric system!

gboezio

I guess there is a harness issue, need to check for conductivity between ignition CPU and rear coil.
Good luck with that electric gremlins sucks

J-Bird487

any ideal how to test that?

hawxter996

so when you take your rear coil and try it in front ,still no fire?

try both coils on front before deciding on a dead coil.

may be an open lead that attaches to coil.

J-Bird487

yep thats what i did. i checked the bad one with the good one. still nothing.

loserbaby

Sounds to be in your harness then, do you have a multimeter? You can "ring" from the CDI box (plug) to the coil plug, then ring the coil to ground. Realistically you should have less than two ohms or so, you will need a buddy (or your wife) to wiggle and bend the harness while you do this to look for changes in your reading. Both coils share a common ground, but there is a splice, I'm not sure where.

Blam

gboezio

Like said, take a multimeter, set it on the smallest reading (usually 20 Ohms) put the two leads together, this is your base reading (close to 0). Then measure between CPU wires and coil, measure the ground from the chassis, if all good, it' still possible that under load the contact goes bad that's tougher but if it's the case write back. The wires should be detached at both ends since you are testing the wires themselves.

hawxter996

jason

was tinkering around with my bike this evening and found.
that my coils were bad also.
out of couriousity i pulled off the boots and found that the coils were ok.
inside of the boots there is a resistor and spring.
i found that the seat the spring rides in was no longer conductive.
apparently they develop a build up from arcing inside of boot.
check yours that may be your prob also.

J-Bird487

well i dont know if my boots were bad and didnt check them since i had already orderd another new coil and it runs great again. it might have just been the boots all along. i have also heard of a guy taking the resistors out and using a piece of dowel rod in there insted of the resistor. i havent tried it since i think there is a reason the resistor is in there. but thinks to everyone for the advice and the help on trying to figure out my electrical problem. those problems really work your brain over but even after all the new parts i bought, i still saved more money than taking it to the shop!!

8541Hawk

The resistor is in there to cut out stray RF that the ignition system generates or another way to put it is they are in there so people around you, listening to their AM radio won't hear you through their speakers. I pulled the resistors out about 9 yrs or so ago and replaced them with a machined piece of brass. Did it make any changed- not really but it didn't hurt anything either.