Tuning a Mikuni carb for in-line-4 GSXR-250R

[paul_bfree]

Hi all,

I have searched hi and lo and cannot find a manual for a GSXR-250R (in English) for my CJ73A model. Plenty of stuff on the CJ72 model, but they use a dual carburetor. Mine uses four carbs - don't know the type or how to measure the size.

I have rust deposits in them and am cleaning the carbs now, but I want to know how to tune them after. The beast near stalls at about 6000rpm, then screams (under main jet?). I have access to a sychroniser for balancing, but need advice on how to get past the 6000 rpm problem.

Any experts out there??
_bfree

[daaatomic]

you have the slingshot carbs, i think the same as on my katana.mine has 4 mikuni 29mm flatslide cv bst carbs. thats about all i can tell you, other than i personally would leave the tuning to a pro.

[F5 Dave]

Welcome to suzuki & their dubious tank rusting issues. You will need to blow through all the jets, never poke wire. Disassemble, easy enough. Also look under the float jets, the valve will need removing to clean, often there is a filter there too. Chances are they will be 'tuned' fine but the debris was causing the issues. My old suzis were prone to this, only thing that stops it reoccurring is to seal the tank.

Creem make a good tank seal but so do POR. Most shops should know. It is a nasty job, but easy enough. Just wear gloves when handing the chemicals. . . . Including the sealer paint stuff, as I sit here typing with stained hands having done a tank this weekend. Then after properly dried one must find how the tank breaths & open those holes & the small hole under the tank filler just visible when you remove the cap & look hard. The tap will have to be blanked off with a piece of metal & some gasket paper.

to requote myself just in case you were thinking that a filter would work
"My old suzis were prone to this, only thing that stops it reoccurring is to seal the tank."