BST36SS carb expert needed.

[Guest]

Hey all, I have a thread started over here http://www.thegsresources.com/_forum...od-Won-t-start

Now that it looks like the carbs are culprit, I need to figure out how to fix them and get my bike running.

Thanks!

[JTGS850GL]

Real simple... Follow these instructions to the letter and you'll be good to go:

http://www.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

[posplayr]

send them to Chef1366

http://www.thegsresources.com/_forum/showthread.php?148764-I-rebuild-carbs

[JTGS850GL]

That would be even more simple.

[yoshisakan]

You both linked me to CV carb resources, these are flatslides.

[posplayr]

You both linked me to CV carb resources, these are flatslides.

I have 4 sets of those BST36SS carbs, what kind are they again? They are not RS Flatslides, but even that doesn't matter; you seem to have a hacked mess and needs someone to straighten it out.

[akckhim]

If those are off a 750 katana they have very small pilot jets plug up very easy. Second the oil motors dont like a weak battery when dead cold. The faster it cranks the better.

[yoshisakan]

If those are off a 750 katana they have very small pilot jets plug up very easy. Second the oil motors dont like a weak battery when dead cold. The faster it cranks the better.

This is what I was thinking too. I'm going to look through the pilot circuit and replace the gas.

[yoshisakan]

I have 4 sets of those BST36SS carbs, what kind are they again? They are not RS Flatslides, but even that doesn't matter; you seem to have a hacked mess and needs someone to straighten it out.

They're from a 1995 katana 750 I guess. They are mikunis, but I thought CVs were limited to the 1980s carbs.

[posplayr]

They're from a 1995 katana 750 I guess. They are mikunis, but I thought CVs were limited to the 1980s carbs.

You can call the BST's a CV flatslide but that is close as they get to being a RS flat slide. The BST36/38/40SS was used on most all GSXR 750 and 1100's from 86-92 as well.

[chef1366]

Oil cooled carbs
I know these carbs and you really have to go through them.
PM me your contact info and I'll walk you through it.
Bill

[yoshisakan]

Thanks Chef, PM sent.

In short they are katana carbs, stock katana emulsion tubes, dynojet bandit 1200 needles and 155mains, mikuni 32.5 pilot jets, .5mm fuel air jet (Not removable) and 1.5mm pilot air jet (stock katana).

I'm wondering if the needle/emulsion tubes mismatch is causing a problem.

[yoshisakan]

After talking with Chef, he helped me determine that the needles for the bandit are not compatible with emulsion tubes from the katana. Here are the breakdown of BST36SS Emulsion tube sizes from factory pro's website:

I believe these measurements are related to the needle. Which explains why the Bandit needle is smaller than the katana needle. The site also says that all emulsion tubes are 40mm in length, so any of them should be compatible. I'm going to call today to confirm.
89-97 Katana - 3.0mm
88-92 GSXR750 - 3.0mm
96-00 Bandit1200 - 2.5mm
89-98 GSXR1100 - 2.5mm

Which ever set I go with, I'm opting for nickel plated emu tubes and titanium needles. Thanks for the recommendation here Chef. I'm hoping the bandit 1200 factorypro emu tubes are compatible with dynojet bandit 1200 needles. If so I'll just get the emu tubes and call it a day.

[yoshisakan]

After looking at the microfiche, http://www.suzukipart.com/oemparts/a...637/carburetor, I noticed that parts 6 and 9 are different between bst36's with the 3.0mm needle and those with 2.5mm needles. Will this cause a performance problem? I don't want to have to replace the piston valves if it's not necessary as they are expensive as hell. I'm thinking that it might make it draw through a little more air, but I could be completely wrong here.

[yoshisakan]

Alright, carbs are back together. The bike idles now, almost. When I hit the throttle it will rev but then promptly dies after that rev. Previously it would die as soon as I opened the throttle, I moved the clip from 2 to 4 notches down to see this improvement. I am using 155 mains, drilled out the main air jet to 1.5mm to match the bandit setup. There is definitely something wonky with my starting/pilot circuit. Currently I'm at 1.5 air jets, 32.5 pilot jets, and the pilot jet's are covered with rubber plugs. I don't see any change in engine speed when adjusting the pilot air screws. My next plan is to bump up the pilot jets to 40s. I feel like 4 clips down and 155s should be way too rich.

Cylinder 4 is not firing and I can't figure out why its not getting fuel. It really doesn't make sense. I've checked the circuits passages and jets and it should be getting fuel. It's absolutely getting spark.