GSXR600 Misfire

[johnmc]

Hi all,
I have a GSXR600 97 that suffers from a misfire. I've had the carbs apart and cleaned them (I think), they've been balanced, I've played with the mixture adjusters but still haven't found the fault. I've put new plugs in and checked the condition of the spark which is strong and appears to be regular on all 4, the colour of the plugs dont give any clues.
As a last resort I thought I would try the Colourtune Kit to see if at least it would tell me which cyl. was at fault.
If there are any Colourtune experts out there please help.
When the plug is fitted and connected to the plug cap/coil using the flexible connector, the spark skips from the flex conn to the valve cover (which forms a deep hole to the cyl head). I've tried puting a rubber sleeve over the flex conn but it still does the same thing. I've phoned Colourtune for some advice but they tell me that they have never heard of this problem before and couldn't help me. If anyone out there can give me any clues as to what might be the problem either with the Colourtune or the misfire I would be very greatfull

[Rowey]

Check the exhaust manifold. Check the air-box to carb to head manifolds. Check the coils and all electrical connectors.

If it's misfiring on one cylinder. One exhaust will be cooler than the others after start up. This should help you narrow down what to check.
____________________
ZX6R C6F.
Never argue with an idiot. They'll only bring you down to their level, and beat you with experience.

[johnmc]

Thanks for that Rowey, I should hae some time to play with it this weekend.
I'll let you know how i get on.

[robocog]

can you use thicker rubber hose/tube to cover the flex connector?
It would obviously have to have a wide enough bore to see the colour of the spark though!
(old hose pipe?)

Those flexy bits are not the best quality items...usually I manage to break the crimped end and leave it behind in the plug cap

Have you "nicked" the outer insulating cover of it to cause it to be able to produce a spark to the valve cover?

If the insulation was thicker than the gap in the plugs then it may help (as it would be using the path of least resistance?)

Another vote for spitting on the exhaust headers if an infra red temp probe is not available

I have had mixed sucess using colourtune

Works great when its carbs AND good old points
Had some funny moments when trying to use it on EFI/ECU controlled fuel and spark engines
Kit car did have carbs but was an ecu controlled spark
Made my shift lights dance a bit and caused the rev limiter to kick in and out and the timing to do random stuff, which definately didn't assist me in tweaking and matching the idle mixtures

Regards
Rob
____________________
Needs a bigger garage...

[Rowey]

Easy ways to check the exhaust manifolds/seals aren't leaking is to put a strip of tissue paper near them. If they're leaking then the tissue will flap about.

Another is to use a cigarette. Meant to be good for intake checking too. Although I've never tried it and you would need fairly still air.
____________________
ZX6R C6F.
Never argue with an idiot. They'll only bring you down to their level, and beat you with experience.