Noob to katanas.....dealing with carb issues

[Katana600-4me]

Hello all, first post
I recently acquired a 1992 gsx600f which ran fine minus a fuel leak. Discovered it was a bowl seal. I put the carbs back on and the rpms raced to 10000 on start up. Lubed the throttle cable and cleaned the carb again, now it's acting even stranger. I've taken it apart 3 times but I can't find the problem. Currently with the choke on it idles at 3000rpm then after like a minute it goes down to 1500rpm, but with the choke on its squirting fuel out one of the 2 little holes on the airbox side if cylinder #1. Then with the choke turned off, the idle slowly raises to 6000-7000rpm. I attempted to try to lean it out thinking its running rich, but even with the fuel mixture screws almost all the way in its still doing it. The throttle plates are at normal idle position so they are not the problem either. I guess this is what happens when a fuel injection person starts working on carbs lol. Any help at all would be appreciated and if you need more info just ask. Thank you all and god bless.
P.S. throttle cable not hooked up and idle speed adjuster not the problem because backed it off too far and came off lol

[shpielers]

Go to the wiki and download and read carbs 101. Sounds like you have a leaky float valve but I'm willing to bet your carbs could use a thorough cleaning too. Carbs 101 will walk you through getting them taken apart, cleaned, and put back together again. Issues idling are generally related to pilot circuits being dirty, so no shortcuts on cleaning - teeny tiny small passages in the bodies of the carbs won't get cleaned out by spraying carb cleaner through them for 5 seconds. Good luck!

[XXWoodmanXX]

Definitely 2nd taking a detailed look @ Carbs101. Same as above....sticky/leaking float valve. And, as per recommendations, take your A/F screws back to 2.5 turns, and then make sure u sync your carbs. Good luck.


I, too, was in your shoes no more than 2 yrs ago. Very 'green' when it came to katanas, not realizing just how touchy their carbs can be. Then, in time, I learned how to THOROUGHLY clean and re-assemble the carbs, knowing what to pay extra close attention to. Now my '91 600 runs fantastic. Good luck sir! Please keep us informed as to how she's running, as there is tons of informative and knowledgeable ppl here

[KatanaGSX92]

And Welcome to KR!

[Katana600-4me]

Thanks for the advice guys, ill look into that carb 101. A buddy at school was talking to me about a metering sum thing, what and where is that just so I know, and what can I use to clean those little holes? Thanks for the advice

[shpielers]

...multi meter? Volt meter? Not really sure what you're talking about there.

Berryman's Chem Dip - most auto stores carry it. You disassemble the carbs and soak them and the jets for 24 hours, then spray the holes/passages with carb cleaner and compressed air (both from cans) then reassemble them. Some people like to try reaming out the passages - if you're going to do this, don't use wire, fishing line is a safer bet. The fishing line isnt strong/hard enough to mar the metal. But after a 24 hour dip, I doubt that would help anyways, should be clean as a whistle.

[Wild-Bill]

Welcome.

Was your friend talking about a manometer? That's a multi-position vacuum gauge, used to syncronize the carbs. They look like this:
like this:
or (home-made) like this:

[Katana600-4me]

My bad, it's a metering valve he called it......but how did u make that monometer? And what is a carb metering valve

[Katana600-4me]

Ok gents your guys advice worked wonders, rebuilt my carb to carb 101 exactly off kat wiki, no longer spraying fuel out the front of the carb, but my idle with the choke off is now 3500, which is conciderably better than the 10000 I started at and the 7000 I was at. Could this be because I don't have an air box? Or could it be a vacuum leak, I spent all afternoon looking for one and half a can of wd40. Any ideas where to look or what it could be. You guys have been katana saints and I appreciate all the info.

[92xjunker]

you really should have the airbox on while tuning and syncing the carbs. The carbs actually need the (OEM type) air filter to operate correctly. was a sync done? Not a bench sync, that is just to get the motor to run.

[Stumpy]

If you don't have an airbox, what DO you have?

[Katana600-4me]

I'm currently a broke uti student lol, can't afford an airbox currently using micro fiber as a filter, the bike idled fine when I got it, but now that I fixed the fuel leak its doing this, is there a way to get it to idle currectly for the time being, until I get an airbox?

[arsenic]

Doesn't matter, if it's CV carbs without the airbox. No matter what it is, it's called an "epic fail".

[Katana600-4me]

But it idled fine when I got it, and it didn't have one.....soooo I fixed it correctly and now it's acting up?

[Stumpy]

Doesn't matter if you are a broke student or not, your bike without an airbox is simply not going to work.

Get one! Why on earth do you think manufacturers go to all the expense and time and effort to put a big hollow plastic box inside the frame?

You are a student, reading something useful hopefully - so do some research! Bernoulli, Pitot and Venturi come to mind.