1992 GSF400 Carb Conundrum

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Variablevalves suck
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Bike owned: GSXR Carb o'ring kits supplied
Location: Stoke-on-trent
Re: 1992 GSF400 Carb Conundrum

Post by Variablevalves suck » Wed Jan 06, 2016 9:30 pm

Yes only three adjustments on the mikuni.

Obviously a vacuum adjuster is most accurate but standard bench tune is to do the adjustment and then open the throttle stop until you can slide something under the throttle valve, usually a small drill bit and feel the gap at each carb, readjust etc.

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Re: 1992 GSF400 Carb Conundrum

Post by lknbandit400 » Thu Jan 07, 2016 2:48 am

Variablevalves suck wrote:Yes only three adjustments on the mikuni.

Obviously a vacuum adjuster is most accurate but standard bench tune is to do the adjustment and then open the throttle stop until you can slide something under the throttle valve, usually a small drill bit and feel the gap at each carb, readjust etc.
Agreed. That's basically why I did. I used a wire maybe .030" thick.

I plan to buy a sync tool once I get the bike at least in manageable range of operation for sure. Thanks for staying tuned. My carb parts from Partzilla come in tomorrow so I hope to post up pics of how far I get in reassembly with new parts and o-rings.

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Re: 1992 GSF400 Carb Conundrum

Post by lknbandit400 » Thu Jan 07, 2016 10:38 pm

First predicament with NOS parts has arisen. Some parts were back ordered but I did receive a partial order. Please let me know what you think of the following:

First, I'll say that I'm aware the Dynojet kit requires the small plastic ring under the needle clip be drilled out.

Here is a picture of the new needle ring on the left and the old on the right. You can clearly see that the ID of the new ring, is much smaller than the old. Too small maybe.

It is number 10 in the part fiche. A picture of the part number is below also.

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Well here's the predicament: with the new jet needle, the ring only goes a portion of the way up the needle before it wedges itself and gets stuck. Here's a picture of how far up the needle it goes. For reference, the old spacer will go all the way over the needle, even over the thickest part. Certainly that's not how it should be. I'm confident the part numbers are right. The needle P/Ns are identical between the California model and regular import, and the ring spacer part numbers are the same as well, so I'm pretty confident I got the right thing...

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lknbandit400
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1992 GSF400 Carb Conundrum

Post by lknbandit400 » Thu Jan 07, 2016 10:41 pm

Just a thought: is this a press fit? Do I need to force the ring up into position right under the clip?
Last edited by lknbandit400 on Fri Jan 08, 2016 1:32 am, edited 1 time in total.

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Re: 1992 GSF400 Carb Conundrum

Post by lknbandit400 » Fri Jan 08, 2016 1:32 am

That must be it - if I apply force to it, it will slide and stretch up the needle. Not sure what kind of resin that's molded out of.

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Re: 1992 GSF400 Carb Conundrum

Post by lknbandit400 » Sun Jan 10, 2016 9:06 pm

Well this happened today...

Another 1992 joined the stable - this one in not as good of condition. But for a straight trade for a Yammie Enduro I had, I considered it a good deal considering its more or less complete, and came with a lot of extras like a Pingel, extra set of carbs with tons of carb parts, extra CDI, K&N filters that won't be used most likely....etc.

Now I at least have a parts bike :)


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Re: 1992 GSF400 Carb Conundrum

Post by SevenThreeSeven » Mon Jan 11, 2016 12:18 am

Interesting... where did the new addition come from?

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1992 GSF400 Carb Conundrum

Post by lknbandit400 » Mon Jan 11, 2016 12:33 am

About 20 minutes down the road - dumb luck. The last time one came up, it was a year ago. Popped up about a week ago and so happened that he was interested in a trade offer.

I have some investigation work to do with the carb parts he gave me. It came with some needles that aren't stock and aren't Dynojet either. I wasn't aware there were other kits out there.

In other news, all my carb parts came in from Suzuki except two needles which are back ordered nationally. Guy said it could be a month.

The carbs on bike #2 are stock (no kit) and just cleaned, but the PO said the bike started and ran much better on fresh plugs and the ones he has in there are quite old. I'm going to throw some new plugs in tomorrow and see what happens before stealing the two lacking needles from that bike.

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1992 GSF400 Carb Conundrum

Post by lknbandit400 » Mon Jan 11, 2016 9:58 pm

Can you gap multi-electrode spark plugs? Everywhere I have read says they come pre-gapped and not to touch it. But in that case why would the manual include a spec?

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1992 GSF400 Carb Conundrum

Post by lknbandit400 » Tue Jan 12, 2016 3:07 am

Gents, I was able to ride my first GSF400 tonight and boy, why a blast! It's quite the little rocket ship and its plenty of bike for me. I'm not a madman on these machines.

Still getting used to the clutch feel, but o got a video. Hope this link works. Sorry for the lack of light.

http://s904.photobucket.com/user/greyro ... t.mp4.html


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