Mikuni BS40 CV carb infomation, GT750

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tz375
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Mikuni BS40 CV carb infomation, GT750

Post by tz375 »

The page on carbs has been updated to include SUDCO part numbers for jets plus a better explanation of the difference between BS type pilot jets and regular VM style pilot jets
http://pinkpossum.com/GT750/carb/BS40carbs.htm

Not sure where the right place is for this.
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Re: Mikuni BS40 CV carbs

Post by oldjapanesebikes »

Nicely done - thanks ! :up: I would probably have put it in the 'Repairs' section, but really it doesn't matter.

I see on MikeSX site he also has other parts which seem reasonably priced and might fit - viton tipped float valves for example. He also shows a choke lever that looks a lot like the original one in the Suzuki's under his part number 48-0777. Wonder if it would fit ?

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Re: Mikuni BS40 CV carbs

Post by Suzsmokeyallan »

If its like the one in the photo, its the exact part for the buffalo CV carbs.
Two strokes, its just that simple.

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Re: Mikuni BS40 CV carbs

Post by oldjapanesebikes »

Suzsmokeyallan wrote:If its like the one in the photo, its the exact part for the buffalo CV carbs.
The photo is off the MikeSX web site - it does look the same as Suzuki used doesn't it ?
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Re: Mikuni BS40 CV carbs

Post by tz375 »

Early XS650s used BS series carbs in 38 and 34mm. Later BS carbs are different in too many ways, but the early ones have some parts in common. And at those prices, it pays to experiment.

I have Z-6 needle jets and while in theory they are significantly larger than GT Z-0 jets, the matching needles are also fatter but with a different taper, so there is scope to tilt the fuel slope slightly for different pipes and filters.
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Re: Mikuni BS40 CV carbs, GT750

Post by Coyote »

The step leading to the pin looks way too deep. I have a BS40 choke lever here and the step is 3mm. That looks like 6 or 7mm. Maybe more. I seriously doubt it would fit. I sure would like to have that bushing though. :(
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Re: Mikuni BS40 CV carbs, GT750

Post by tz375 »

I hear you Chris. I have a lever nicely re-plated but no stepped bushing and I'm missing that small link that goes on teh choke rod. I'm thinking that I'll have to grab a piece of steel and fabricate one
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Re: Mikuni BS40 CV carbs, GT750

Post by Coyote »

tz. Here is a drawing I made up for a replacement bushing. This might help. I am going to try to get this made at the machine shop I used to work for. Maybe I should get 10 made as this is a very common lost missing link.
The choke lever is formed from 2mm steel, so the .090 land will allow you to mount a retaining washer and still have about .010 play.

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Re: Mikuni BS40 CV carbs, GT750

Post by tz375 »

Cool. Thanks for that.
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Re: Mikuni BS40 CV carbs, GT750

Post by Bluesmokebaz »

I have fitted the Yamaha lever but had some stainless steel choke rods made 5mm shorter and all was good cheers BAZ.
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Re: Mikuni BS40 CV carbs, GT750

Post by Suzsmokeyallan »

Mikes XS has the eight hole choke assembly gasket as a separate item, item #48-2011

As mentioned already Mikes XS has the choke lever assembly, I stand corrected it does have a slightly longer stepped collar and a deeper standoff, but it has the knob thats usually missing, item #48-0777
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Re: Mikuni BS40 CV carb infomation, GT750

Post by Suzukidave »

Youtube carb video http://www.youtube.com/watch?v=Cukul7Tq ... 687CE68076" onclick="window.open(this.href);return false;
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Re: Mikuni BS40 CV carb infomation, GT750

Post by Vintageman »

Wow!!!!!!!

I just realized for th e GT750 with Cvs the pilot jet is a BS30/96 not a VM22/210
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Re: Mikuni BS40 CV carb infomation, GT750

Post by rngdng »

Vintageman wrote:Wow!!!!!!!

I just realized for th e GT750 with Cvs the pilot jet is a BS30/96 not a VM22/210

Pilots for the BS carbs are very different, but they are numbered the same. Confusing. Ask Coyote about the effect of getting them mixed up. Lots of us have learned that lesson the hard way.


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Re: Mikuni BS40 CV carb infomation, GT750

Post by Suzukidave »

Looks like we have a intruder :shock:
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