1982-GS750T - Oh my Carbs!

[SamLack99]

Suzy has a flat spot.

From idle to 1/4 throttle, she's a dream boat.

But as soon as she hits 1/4 throttle, she bogs. If I keep twisting the throttle, she'll kinda get over it, but it ain't a pleasant experience.

In the spirit of starting with the 'low-hanging fruit' and building up from there, I'm in the process of stripping down and cleaning her carbs (again).

I've got a couple of questions that will follow after this photograph.



Question 1: This time around, I've made sure to check everything. And that's when I noticed Carb 3 has a 45 Pilot Jet, yet Carbs 1,2 and 4 have 42.5. The factory setting is 42.5.

Does anyone out there have a spare 42.5 Pilot Jet (OVERALL LENGTH = 14 mm. THREAD DIAMETER = 4.9 mm. 6 holes in shaft for a Mikuni BS32 (CV) Carburetor? I'm in the UK and either my GoogleFu is weak (possible) but I can't seem to source one from my usual sources - mainly cmsnl.com





Question 2: My Main Jets are all 145. But Factory settings call for 112.5 - Should I keep the 145's or replace with 112.5? Suzy now has an original exhaust instead of the noisy Delkevic 4 into 1 pipe she came with. But she still has pods. Granted they're K&N, but they're better than the one's she came with. Oh, and I've fitted Zed1015’s air correctors in the 4 O’clock position on each carb.



Thank you very much for your help in this part of getting Suzy back on the road and running great in time for Summer =)

[Katana1074]

Suzy has a flat spot.

From idle to 1/4 throttle, she's a dream boat.

But as soon as she hits 1/4 throttle, she bogs. If I keep twisting the throttle, she'll kinda get over it, but it ain't a pleasant experience.

In the spirit of starting with the 'low-hanging fruit' and building up from there, I'm in the process of stripping down and cleaning her carbs (again).

I've got a couple of questions that will follow after this photograph.



Question 1: This time around, I've made sure to check everything. And that's when I noticed Carb 3 has a 45 Pilot Jet, yet Carbs 1,2 and 4 have 42.5. The factory setting is 42.5.

Does anyone out there have a spare 42.5 Pilot Jet (OVERALL LENGTH = 14 mm. THREAD DIAMETER = 4.9 mm. 6 holes in shaft for a Mikuni BS32 (CV) Carburetor? I'm in the UK and either my GoogleFu is weak (possible) but I can't seem to source one from my usual sources - mainly cmsnl.com





Question 2: My Main Jets are all 145. But Factory settings call for 112.5 - Should I keep the 145's or replace with 112.5? Suzy now has an original exhaust instead of the noisy Delkevic 4 into 1 pipe she came with. But she still has pods. Granted they're K&N, but they're better than the one's she came with. Oh, and I've fitted Zed1015’s air correctors in the 4 O’clock position on each carb.



Thank you very much for your help in this part of getting Suzy back on the road and running great in time for Summer =)

Hi...

Sorry just had a look through my jet stash (im in the UK), I only have a size 40 with bleed holes, I can only find 1 used item on ebay:

https://www.ebay.co.uk/itm/136942061220?_skw=SUZUKI+GS1000+1980+-+1982+MIKUNI+CARB+CARBURETTOR+OEM+MIKUNI+PILOT+JET+42.5&itmmeta=01KK9R7G0FFN28ZS60JRJM71KX&hash=item1fe26206a4:g:Zu4AAeSwiyppZRv8&itmprp=enc%3AAQALAAABMGfYFPkwiKCW4ZNSs2u11xDkgBiA8QjGG%2FE%2FFpxuXcZtTygPl50l57cCDy9GDr615PNa--ALg%2FShier5K6up%2FgBk94L1QK%2BnofSxb6fqCvDYE4mTVv5WfNR%2BcRS%2BbAhdOx9MQulU%2B1aetl77IuUizKHexA3Rq1oreJiXHJXYWM6deAIrxomZUdgt6IBzwAPSZ8Tp%2BeGdVG26FU%2BNYroFCRamlO9Oiw8i0GGIPaSSjEC%2BkHTcvQNaPt8E9xLMimV5B2RT1cIcwjwkAlePM6LmipeznMUjkxzwJOLgwKWaFMEYM3qsiKRub61fNLqNB80BmmOOp%2FuWgnRspXYxH8xBXS4x0c06vaXhjR5r5yR0zQ9sDGbJwDQzeaNBMa8xzLPjh0bZUmz%2BKoSMM4rYCNr5rBo%3D%7Ctkp%3ABk9SR9SAnriaZw

as for your 1/4 bog this chart should help you out:

jet-function-range.jpg

[Nessism]

Zed says to bump one size main over stock when using his air correction jets, so that suggests 115. I'd try those and see how things go

[SamLack99]

Katana1074 - Thanks for the diagram. Once I get the pilot jet and main jet parts, I'll put her back together and see about my 1/4 throttle onwards bog. If it's still not fixed, looks like I'll be getting into the wonderful world of carb needles =)

Nessism - Thank you. I didn't know that. I shall seek out 115's

Thanks again everyone.

Time to hit up Google =)

I'll keep you posted.

[GSXR7ED]

Exciting post!

I didn't dare take mine apart...I had Steve (GS Whisperer) rebuild mine a while ago.

It's great to see enthusiasm so keep the thread going!

[rphillips]

I know nothing about air corrector jets, but back in the day, pod filters, especially with the bigger oval K&N's the mains would need to be raised quite a bit, but not near 13 sizes. I'd guess maybe125 to 132.5 would have been close. The exhaust. will have way less effect on the jetting than the pods.... That being said, if ED says 115's with air corrector jets, that's probably a pretty good place to start.

[Nessism]

Dynojet used jets with a different numbering convention. I wonder if a kit was installed by some previous owner. That would explain the seemingly huge mains.

[Rich82GS750TZ]

That's a pretty sweet looking "T" Sam. Have you every had it running well with the pod air filters?

[rphillips]

Different Co.'s use different #'s for the same size jets ???? Never would have thunk that...Wouldn't that get terribly confusing??? How could you be sure if you ordered a bike won't start at all jet, you'd get a bike won't start at all jet if some use different #'s.??? That just don't sound right.

[Rich82GS750TZ]

Different Co.'s use different #'s for the same size jets ???? Never would have thunk that...Wouldn't that get terribly confusing??? How could you be sure if you ordered a bike won't start at all jet, you'd get a bike won't start at all jet if some use different #'s.??? That just don't sound right.

Rphillips, when you type a # next to a number, you have to leave a space between them or you’ll get a funky link like I know you don’t know how to do.

Examples:
if you type these without a space you get the links to strange places:
# 145 bike won't start at all
# 146 Fork oil level?
# 147 Using LED Tail/Stop light bulbs
# 148 Fork oil Change
# 149 blinkers don't work
# 150 regulator/rectifier question?

these links all take you to threads from 2002. Why? Who knows. Just more vBulletin Fun, I guess.