Needle jet length

[Bikertucker]

New old member here. Working on a friends 1982 GS1100G. Have found aftermarket jets in the carbs and have sorted that all out. My question is can anyone be kind enough to supply me with the OEM length the needle jet protrudes out of the bottom of the slide piston on the Mikuni carbs. Engine floods out at w.o.t above 4000 rpm and I end up with gas in the air box. Just wanting to eliminate someone severely raising the needle as part of the problem. Have tried researching but have grown dizzy from reading and have not found my answer. Thanks in advance.

[Nessism]

Gas in the airbox is caused by float valves that are not closing, allowing the float bowl to overflow. The Needle Jet has nothing to do with that.

https://gsarchive.bwringer.com/mtsac/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

[Bikertucker]

Thank You for your response, but it does not answer my question.

[Nessism]

You might want to remove the needle and look for yourself. This carb rebuild tutorial provides details on what to look for. I say that because it seems unlikely that anyone here has a spare set of 1100G carbs laying around that a slide can be removed from.

https://gsarchive.bwringer.com/mtsac/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

[Bikertucker]

Am looking for just the stock length, did Suzuki never publish the stock length. Could you verify the correct needle as a (5D58) part #13383-49200. I’ve not wanted to disassemble the slide piston for fear of breaking dried out fragile plastic old parts. If I can verify correct needle I would try to dissemble one and make sure added washers under the needle are not there.

[Nessism]

Needle height is not affected by washers under the needle. Height is controlled by the spacer thickness on TOP of the clip.

Regarding fragile plastic, there is no plastic under load in that system. The only part under load is the C clip.

[Bikertucker]

None of these carbs have the rubber pilot jet plug. What problems are caused by these plugs missing?

[rphillips]

You got to have those plugs... My opinion from what I saw 40 yrs ago, on a "80" GS1000E. Mechanic left them out, started bike, revved it, rode across parking lot to st, pulled out on st and the thing just wouldn't go. He limped back in and said aw sheet, and pointed at these 4 little plugs laying on the bench. Took it all back apart, installed plugs and all was well.

[Bikertucker]

I think we’re onto something. Will try the pencil eraser trick as a plug for a test. That’s the trouble with working on something so many others have worked on too.

[Bikertucker]

Received the rubber plugs in the mail yesterday and installed. No more bogging down at 4000 rpm till it stalls if kept at wot.
No longer has black sooty plugs. No longer getting fuel into the air box. Nice smooth solid pull from low rpm till 9k. Friend stated he hit 90 mph while just in fourth gear. So… if those rubber plugs are missing from all four carbs it can cause all the above problems. Thanks rphillips for your practical response. Let me know I was on the right track.

[rphillips]

I'm amazed my memory had lasted that long. Glad all is good... 90mph. in 4 th, he must've been taking it easy, thinking it should've easily done that in 3 rd.

[Bikertucker]

Breaking in a new set of rings per manufacturer. I’m just glad that after two years of ownership he’s finally having fun with it. Was riding a very nice Yamaha 250 street bike that could out preform his poor Suzuki. He said 90 mph was half throttle fourth gear. Suggested he come back in a few hundred miles and we’ll check compression and carb sync again.