carb tuning, running rich, bad needle jets?

[elbandtioCA]

or to make matters short: does anybody know the part number the needle jets that should be on my bike (it is an american bandit with 32mm carbs)?  that way i can check myself to see if suzuki ordered the wrong size.  my shop manual says that american gsf400s have a size "0-9" needle jet, but if i recall correctly there was a long series of numbers etched into the side of the jet.  now i just have that sinking feeling that my mechanic got the wrong part and installed it.

[interfuse]

Download the manual. All the carb specs are listed, including diagrams.

Stock settings for your bike would have been
MJ 102.5
JN 5EZ74
NJ 0-9

He should be able to get it to run RICH with the jet kit installed... on the right (or wrong clip) it will foul plugs in a couple of blocks.

Does he have the air filter installed??? After sniffing gas all day sometimes you forget the easy shit... LOL.

[elbandtioCA]

hey interfuse...i'm not sure of the numbers on the jets he just installed.  if they are the wrong part, i won't know unless i (or he) opens it up again.  but lets say he put in the wrong NJs and they are too small, making the bike run lean.  would using the aftermarket needles, on the right clip position, be a decent way to fix the problem--to compensate for the leanness?  or is this just "treating the symptoms"?  if the only proper solution is to install the stock NJs (0-9) then that's what I want him to do--it doesn't seem right to try these half-ass solutions like playing with aftermarket needles.  but if both ways lead to the same result, then i guess it isn't a problem.  i just don't know enough about carb tuning to know what is right...

[pmackie]

It sounds to me like he got the wrong needle jets. If he was concerned, he should have checked/verified before he installed.

He will need to install the correct needle jets and appropriate needles for the bike to run correctly, IMHO.

[interfuse]

Yes double check the needle jets... they may just appear smaller when they aren't worn... it's hard enough to get the b4 to run well with the right parts.

[elbandtioCA]

thanks guys for the input.  here's what i've learned: my bike is a CA model with a CA specific carb.  suzuki doesn't supply the CA model needle jets any longer, but only the jets for the non-CA US model.  the part number is different, but both jets are listed as "0-9".  so i'm not sure what the difference is.  i called the suzuki dealer to ask if the non-CA jets would cause a problem in a CA model carb, and the guy basically said "no-comment."  but the bike is running lean, so my mechanic thinks that having the non-ca jets could only be a good thing, because with the CA jets it would run leaner.  i wonder what the difference is between the two parts, i.e. if they have different part numbers and yet they both are size "0-9."  maybe the problem now has nothing to do with the needle jets, but with the slightly modified airbox or the aftermarket exhaust. i was just hoping to reduce variables. 

[gsxr400 racer]

Find a dyno

[elbandtioCA]

finally the bike's running well!  whether or not the needle jets are the stock ones, the aftermarket clips (factory pro, i think) that the prev owner provided were the solution.  i spent yesterday riding around on it and it is great.  i was starting to get anxious because it was at the shop for a really long time, but in the end things seem to have worked out.  thanks to everyone who gave me suggestions on here.

[gsxr400 racer]

 

[interfuse]

Good stuff. Nothing better then riding your bike when its running well.