Carby tuning

[parto]

I have a 92 ZXR 750 with a slip on, It also has a jet kit which i didn't put in.

It has a small dead spot around 7 so i think i need to raise the needle one click to give it more fuel.

Has anybody got some data on what works best for this bike.

Cheers Parto

[Ticketyman]

At 7000rpm I think she'd be on the main jet, so playing with needle height won't do much. I might be wrong. How many klms has it done and what sort of jet kit is in it? Has it also got an after market air filter? Check out FACTORY PRO website, drop in there carb kit and bob's your uncle.

[parto]

Yeah just got the bike iv'e restored it, 90,000kms, standard air filter, 4deg ingnition advancer, and not sre what brand jet kit

[Gosling1]

put the jet kit in first before you start playing with needle heights. See what difference this makes. The jet kit should specify which clip position is needed anyway.

[parto]

don't have any paperwork on the jetkit so i don't know where it should be

[IsleofNinja]

If you decide to put a Dyno jet or factory pro jet kit in, pay very close attention to the float settings as in >perfect< for all four carbs.

a dead spot / flutter at around 7000rpm --- as you power on mid corner???? >>>> carb synch

[Gosling1]

don't have any paperwork on the jetkit so i don't know where it should be

mmm okay, thats a bit of a shitter.....

maybe worth a google search on the US forums for jetting - do you know if its a Dynojet kit, or Factory Pro ?? Those websites could also be worth sending an email to, seperately of course - just ask them the questions about settings etc, most of these places will at least give you a starting point....

and yes the advice from Matt about balancing the carbs and setting float heights *exactly* the same is 110% on the money......its little things like this which can make a big difference to the overall success of any jetting exercises....

[Bogan]

Where do you live? What's the height above sea level?

[parto]

How is the best way to do the float levels

I live on the coast

[IsleofNinja]

Where do you live? What's the height above sea level?

Fark me --- here we go again ..................................





re floats ,:
Carbs off - bowls off - float hinge pins on the upper side - tilt carbs until the tangs LIGHTLY contact the needle pin (spring loaded) . If you just tip them on their lid , the weight of the floats overload the springs in the needle pins.
-Measure float height from the gasket base to the round section of the floats.

CVK float measurement = (insert your general Kwakka knowledge here)

[IsleofNinja]

Handy link - http://rds.yahoo.com/_ylt=A0Kjqmk5TSpLq ... ncarb.html

[J-rex]

Some good info here, like others have mentioned......
Here are the links to carb tuning on Factory Pro site.....

http://www.factorypro.com/tech_tuning_p ... gines.html

http://www.factorypro.com/tech_tuning_p ... edure.html

Float height one has quite a few pics which might help you out a little..
Good luck!

[mick_dundee]

But as a heads up, if more than 1000 metres above sea level, get a FI bike

[parto]

I live at sea level

[oldman]

I wish I had a carburated bike, it was a lot easier to tune. I used to just buy a machinists drill bit set and see which bit fit through the main jets the tightest, I would take note of the size and drill the jets out to the next size bigger and keep doing that until I got it right. The main thing that will tell you how rich or lean it is is spark plug color. White or pitted insulators indicate a lean mixture, black insulators too rich, and a nice Jim Beam tan indicates a proper mixture. You have to make a quick acceleration run a couple of times then remove whatever plug is easiest, inspect it then ride home and inspect it again. The good thing about drilling the jets is if you screw up just solder the hole up and drill it out with the original tightest drill bit. Also as mentioned before float settings plus the needle jets can make a big difference so before you change anything record your original settings so you can go back if necessary. Good luck!