2000 suzuki gsx750P carb question...

Islandstar

Islandstar

Been Around the Block
Trying to rejet above mentioned bike...it had Keihin CVK32 carbs which are turning out to be a PITA to get right. Went to Dynojet and they said they dont make a kit for for those carbs. Is their a Mikuni equivalent I can use instead? I realize that the Katana and Bandit of similar years have Mikunis instead.
Thanks
 
figuring out needle position jet size. Some of the bikes from that year came with Mikunis which I would be able to get a pre done Dynojet or similar brand kit for. I've tried different jet and needle sttings but just cant seem to get it right.
 
What are the symptoms - throttle position/revs? And are you sure that the pilot jets and main jets are correct?

There used to be a great instruction over on http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html
 
Thanks...I have that and did find it helpful. The issue I'm having is that bike ride well enough up to about 140kmh then it just feels like it has nothing left. The best performance I got was with 110 jets and 2 spacers on the needle. Some reading I've done also suggest that these cars don't respond well to airbox change/modification(read that after and can't get original airbox reinstalled). Idally I would like to know if I can change them out for a Mikuni equivalent. Some models came with BSR36SS carbs.
 
Do your carbs have a float bowl balance pipe like the ram air models have? If so, what have you done with this?
 
hillsy said:
Do your carbs have a float bowl balance pipe like the ram air models have? If so, what have you done with this?
Click to expand...
Sir....you asking me to step out of my pay grade!!! Lol. I have no idea what that looks like... :-\
 
I did some quick research on that model and it seems to be a softer version of the earlier GSXR motor with mild cams and small carbs. It didn't have a lot of top end when new, but it should go more than 140 but seems like it couldn't go more than about 180 kph and was similar to a 600 bandit performance.

Leave the needles and needle jets alone for a moment and see what changes in main jet do for the top end. 105 is stock I believe so you could try a 115 and 120 and see what they do to the top end and then work back to see what needs to be done with the needles.

A simpler solution might be a set of carbs off an SRAD 750 GSXR.

But before you go there, are the plugs new, is the ignition timing correct or has it failed and gone into limp home mode? Do the wheels spin freely or do the brakes drag? What is the compression like across all 4 cylinders?

After those simple checks find a dyno shop to run it and look at what it's doing and they can tell you what the air:fuel ratio is like across the run.
 
Damn!!!! Thanks boss...will Def give that a try. Jus got some 120's coz I thought that might be the issue. I'll let u know how it goes. Would like a set of those carbs tho...off to eBay.
 
OK....spacers out. 120 jets in. 2 turns on the screw. Seems better but still getting slight popping on deceleration.
 
Popping is usually caused by a slight exhaust leak allowing air in to ignite unburned fuel in the pipe.

Air screws on a CV carb are 180 degrees different to say a VM32 Mikuni. It;s easy to know which is which though. If the mixture screw is on the filter side of the carb, it changes the amount of air, so in means rich and out equals lean.

CV carbs typically have a mixture screw on the motor side of the slide , so it changes the amount of air/fuel mix. So on those, out = rich and in = lean.

corrected.
 
That's what happens when I type too fast....

Let me try that again. If the mixture screw is closer to the filter than the engine, opening it up make it lean (more air) and closing it makes it richer (less air).
 
Possibly, but check the exhaust for leaks because that's probably the issue there.
 
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