mystery problems on my sp

[stevo400]

Hai all, I'm new here though I've spent a whole lot of time reading through posts.

I have a 91 gsxr400l sp edition, I have done a load on this bike as it was kinda messed up when I bought it as a restoration project.

Here's what I've done thus far: replace broken rocker arm, reshim and valve clearance adjustment, cleaned out carbs about 10 times and replaced all oring except on mixture screw, set float heights and synced, new oil, new coolant, fresh gas, fitted oem fuel cock, went through all wiring and found lots of damage close to the cdi, I've cut the damage out and resoldered the wires.

Now here's my problems, I don't have a tps, bike seems to cut out as an electrical issue, this will sometimes happen while idling or not, while drivin or not or sometimes it just doens start, I've found that it's electrical cos when this happens I notice there's no spark, I noticed when I mess around at the cdi it fixes it and when it's fixed and I mess around there then it will cut off, so I removed the cdi plug took all the pins out and soldered them to the cdi to avoid loose connections, unfortunetly still happens, but now it seems like when I mess with my regulator wires this happens, I'm hectic confused now, oh sidestand switch is removed and fitted a diode in its place as I've noticed the stand switch has one fitted internally. The bike when running idles a bit off but not too bad, when driving it seems like it doesn't have power going uphill, pulls nice on a flat but won't pass 6000rpm, could this be because of the cdi? Any help or ideas will be tried and appreciated!!

[Variablevalves suck]

Never knew the side stand switch had a diode, thought it simply made or broke a circuit, think there's a diode in the safety circuit but not the switch.

Fault leans towards a broken wire it the seat area,

You can open the loom up there and separate the lighting wires from the engine wires and then check these .
Reg/rec wires run here and are prone to burning out due to water ingress, they can be cut out and wired straight to the battery with an in line fuse if bad.

[stevo400]

Hai vvs,thanks for the reply, do you think it could be a short somewhere on my lighting circuit? If so I should remove all lighting circuits and see if that helps?

[stevo400]

Oh about the side stand diode, I could be wrong but if you check the wiring diagram which I also found on this site you will notice that within the sidestand switch there is a diode which seems internal to the sidestand switch..

[stevo400]

Would you know if driving the bike without the tps could cos the major flat spot or the section where I mentioned the bike won't pass 6000rpm??

[moforockband]

I would put the bike back ignition/set up wise as close to std as you can. I think w/out the tps you would run a retarded advance curve which would make it feel flat.
Nick.

[stevo400]

The loss of power up hill seems to be solved, new spark plugs and also driving the bike as an sp should be driven, I read somewhere that because of the long first gear the bike won't pull properly unless given a good amount of throttle on pull away, ill add that the up hill issue was from stand still and not giving much throttle as I wanted to keep the noise down, bike is quite loud as previous owners removed the baffle.. now next problem I want to solve, when in nuetral or in gear with clutch pulled in, I rev the bike up and it goes up perfect but then returns way below set idle speed and then dies out... could this be too large idle jet??

[moforockband]

It can be many things.
- manifold air leak (check with spray carb cleaner)
- spark plug starting to foul (common gsxr problem) tiny little plugs.
- fuel screws not correctly set. I use a infrared gun to set them. I measure temp of each header and adjust to get them within 10 centigrade of each other.
- Adjusting the back pressure in the exhaust will affect running on a small cc bike more than a large one. Try re-fitting the baffle.
Nick.

[stevo400]

Hai Nick, thanks for the input. I have checked the manifolds allready, seems fine, I like your idea of using a heat gun will check to get my hands on one. Spark plugs are new, ill check for a standard exhaust as this one is way too loud anyway!
Thanks!!

[moforockband]

£20 from Maplin I paid for my infrared gun. Also check your valve clearances and carb balance is spot on. Good luck with it.