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Discussion Starter #1
Ok, the problem isn't getting any better so I better do soemthing about it. I think my ignition/coils are bad. Do I need to replace everything? Just the coils? Is it better to go with a hotter ignition than stock. I know nothing about this stuff so all comments welcome.

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That don't fix it? Get a bigger Hammer
1993 GSXR 1100
 

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May have missed something earlier, but what is the problem you are having with your bike? Is it missing out at a certain speed? How many miles? Had plugs changed recently? I just had a problem with my F2. I took the tank off to remove the air filter to clean it. I put it all back together and it barely ran! I thought I put something back together wrong. It acted like it wasn't getting any gas. It popped, and bogged and was lucky to do 30mph. I checked fuel flow from the tank and it was good. Finally, I drained the tank and put fresh gas in. I then drained all the float bowls on the carbs and poured some fuel system cleaner in the tank. Ran it for a few miles....like new now. :D :D :D

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Thomas

To ride or not to ride? What a stupid question!
 

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Discussion Starter #3
The bike is shutting down at about 8K rpm. Runs fine until then, but once it get's around 8 grand it acts like it hits the rev limiter. The tach falls off, backfires, then goes again. This is a constant thing. If I try to rap it up and hold it, it just happens over and over again. I was told it was probably the coils or the box. I don't know anything about these things. I'm told I should go with "hotter" coils. How do you check the coils, and/or the box?

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That don't fix it? Get a bigger Hammer
1993 GSXR 1100
 

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Almost certainly not the coils - If you had one bad coil the chances that it would misfire enough at 8k to produce backfires & limit rpm, but function properly at any lower rpm are pretty slim. Start with the cheap stuff - are your ignition pickups tight & properly gapped? Are all connections tight? If both of these are true, then you probably need an ignition module, and the only way I know to verify this is by replacing yours with one that you know works. If you have a good relationship with the people down at the salvage yard, maybe they'll let you try one before you spend any money. Or if you have a friend with the same bike. Good luck. I hope this helps.......

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PS Heth, to test your coils, when the bike is cold, take some water and wet the exhaust pipes about 8 - 12" from head. Start the bike, quickly run it up to where you have trouble. Shut it down. Look at the pipes. Do you see or feel a difference in the heat radiating from pipes 1 & 3 as opposed to 2 & 4? If the water evaporates too quickly, use a few drops of engine oil. If either set feels significantly cooler than the other, then you have a problem with just one side of your ign, possibly a coil. Free, quick test. Hope this helps.

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Discussion Starter #7
Well, talked to a couple guys at the shop and they both suspect the box. First question was, "Have you jump-started your bike or charged the battery?" Damn. I think I charged the battery not long before the problem started. And nope, I didn't disconnect the battery first. They said this can send too much juice into the box and burn it out. They recommended getting a Vance&Hines box instead of a stock one. It will probably be cheaper and it is adjustable.

Has anyone ever used one of these before?

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That don't fix it? Get a bigger Hammer
1993 GSXR 1100
 

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Seems somewhat unlikely that a coil would work at one rpm and not another. Connections on the other hand, are subjected to different amounts of vibration and may cut out at the same frequency repeatedly.

Also, the amount of fuel engine needs is probably always similar at 8k. Gunked up carbs could be limiting fuel flow or fuel pump that cant provide more juice than that.

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