My 1995gsxr 750 Has been progressively worse.
The idle is terrible and sounds like its only running on 2 cyl. Taking off from a light it terrible.
It has a really bad stumble and basically no power under load untill it hits 4k, then it takes off like a rocket.
Anything after 4k feels great. great throttle response, no loss of power. as soon as I stop the idle seems to sound fine for a few seconds then drops.
Seems to be fine if the choke is on.
I had ran in to this issue before. It was bad enough to the point where the bike would stumble then die while riding. Switched to petcock to prime and completely resolved the issue. now with the petcock on res/on/prime/ it still runs like shit.
I've tested the petcock. Flows free in prime and flows the same in res/on when under vacuum. I've torn apart the petcock, all seals are good and thoroughly cleaned
I do have a slight vapor lock with the tank but still runs like shit with cap
open.
Replaced plugs with new cr9's
Just taken the carbs apart. all seals and orings are cleaned/no nicks, not dried.
emulsion tubes are good. they seem to be stock. they are marked with a serial number.
Needles are not worn.
Haven't checked float bowl height yet. should be able to check later tonight
carbs 1/4 have 110.0 jets. 2/3 have 112.5
I have a drop in K&N filter, stock airbox. no mods/ full V&H header+pipe with a a thinner baffle/
I believe this bike originally came from Cali. I say that because it has the factory sticker on the frame stating that the bike meets the California emissions laws. And has a massive ugly as fuck canister on the left side of the bike. (4th picture down). if that is the case how can I completely remove that system.
Please help me out with this. Anything would be appreciated. if you guys need any more info let me know. will upload video of the bike running and more pics
Last edited by Adamm Bomb; 10-22-2012 at 03:40 PM.
I'm actually having an almost identical issue as you except my bike is probably at its worst, I'm on my second carb cleaning, I also have a dynojet stage 1 jet kit with 116 main jets. I can't figure it out at all, the carbs are sitting on my kitchen table right now as I'm trying to find anything out of the ordinary, even though there is hardly any wear on my jet kit. Needles have slight wear but everything else looks to be new. My bike only will idle if I have it at 2k rpm, and when I take it out it spits and sputters up to 3500 rpm and after that it will kick out of it do hard that it almost throes you off the bike. I can't find anything bad I got good spark, petcock flows like it should, and I just can't figure it out.
Same prob with my 86. I never got any answers on here about it. I still have issues with it. I am chasing down a possible vacuum leak that a bike mechanic friend said to look for. I will let you know if that works for me.
Thanks for the quick replies guys.
All floats were about 12mm. Currently now set to 15mm.
I'm going to check the pilot screws, but unable to get the brass cap off. any suggestions?
Also has anyone ever taken the extra emissions shit out of a Cali bike.
Ive looked through the manual and it looks like the only real difference is those 4 purge tubes(1 for each carb) that basically go to the canister. Then the canister has a another tube that runs and connects to the lower right rear of the gas tank. In the tank theres apparently a fuel fume seperator. I have a diagram that ill post up. hard to explain.
But couldn't I technically block off those purge tubes which will cut out the need for that canister?
Thanks for the quick replies guys.
All floats were about 12mm. Currently now set to 15mm.
I'm going to check the pilot screws, but unable to get the brass cap off. any suggestions?
Also has anyone ever taken the extra emissions shit out of a Cali bike.
That would have made your bottom end richer, having them set to 12 mm. Anyways, good thing you checked and set them right.
Like Cody said, drill a small hole into eack one, insert a wood screw, and pull it out.
Can't help with the Cali stuff...search through the archives here, I'm sure you're not the first to do this. I would say the vent tubes should not be blocked off, rather vented to the atmosphere (if it's anything like the 38 mm carbs).
Thanks guys. Worked great.
Counted when I turned them in and they were all off +/- half a turn. All currently now set to 2.5 turns out.
I'm going to rip out the all that emissions crap out tomorrow/ reinstall the carbs and try again.
Also sure its been discussed multiple times. but would you recommend DJ or FP.
Last edited by Adamm Bomb; 10-22-2012 at 11:43 PM.
When I bought my bike it had a cali motor in it with no emissions, they had crimped the tubes on the exhaust just outside the jugs, I believe that is all you will be left to deal with once you remove the emissions.
Thanks guys. Worked great.
Counted when I turned them in and they were all off +/- half a turn. All currently now set to 2.5 turns out.
I'm going to rip out the all that emissions crap out tomorrow/ reinstall the carbs and try again.
Also sure its been discussed multiple times. but would you recommend DJ or FP.
Both are good kits and will cost roughly the same.
In short, the DJ kit comes with new proprietary emulsion tubes. You replace everything with new DJ parts, but slide drilling is required.
The FP kit does not come with new emulsion tubes. You will need to order new OEM tubes to run with this kit should yours be worn. No slide driling requred.
Do a search, this has been covered extensively in the past...
Either one you decide to get, be sure to buy the Cali version of the kit...
Placed the carbs in the bike. Connected everything up, and now the bike has no electrical power. The fused connector to the solenoid was melted to the solenoid.
Getting that replaced right now and then I'm going to give everything a try. I let you guys know what happens
Purchased the correct DJ kit for my Cali bike. Have installed everything correctly and rechecked the pilot screw aswell as the float height.
I have also since replaced the float bowl gasket.
I reinstalled the carbs in the bike and am running into the exact same issue in every way(can take another vid if necessary) The jet kit hasn't made any difference at all.
Now is it possible for the coils to break down under certain rpm?
Can this be an electrical issue? Or should I keep trouble shooting the carbs?
I'm at a loss right now. Any help would be greatly appreciated.
Motorcycle: 1994 GSXR 750, finally getting proper parts painted, 1993 GSXR 750 project to rebuild
Posts: 741
Re: Bad Running 95 750
Does the bike stall when you try and start off? Do you smell gas? Pull the plugs see if they smell like gas. It really sounds like the bike is running rich and causing your bogging issues.
Just to be sure with spark have you removed the spark plug books and re sat them to ensure a good fresh connection.
You mentioned it sounds like it starts on two cylinders. Have you checked the coils with a multimeter? Or at least checked all four for a good arcing spark?
I'm leaning towards the carbs even though I've never dealt with a Cali model. I had the same issues with my 94 but I replaced everything from wiring harness to battery to plugs to rebuilt carbs etc. I just got it running perfect. You are close just start simple and go from there.
Is there anything you have done to the bike besides what you have told us. Not trying to come off like a dick or second guessing your work. Just trying to help. These bikes are damn picky! Keep at it and hopefully something I said helps!
If you know your carbs are set to the T, I would move on and look elsewhere (at least rest knowing you won't have to do the carbs again!)...
Like already mentioned, check out your ignition system next. I saw you already have new plugs, good place to start. Time to take out the voltmeter and manual...
Like JSarget said, these bikes are damn finicky. They require constant TLC to keep them running right...once they have been neglected (as most of them are), it's a bitch to get them back on their feet...
thanks for the quick reply guys. Really appreciate it.
I will take the volt meter out tomorrow and check a few things. Aswell as I'm going to hang the carbs off the bike with the fuel and vacuum lines connected. Just to make sure the pilots are completely clear.
Great communication there Adam...you are definitly on the right track to getting it sorted.
blow them dry with compressed air! 
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