Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 175 & 200 Talk => Topic started by: Motogary on November 09, 2022, 10:21:12 PM

Title: Mach II SS carb kits
Post by: Motogary on November 09, 2022, 10:21:12 PM
Anyone know where I can source carb kits for one of these? I need 2 kits for the Mikuni VM17-18 carbs on this bike.
Title: Re: Mach II SS carb kits
Post by: farmerdl on November 11, 2022, 07:57:32 AM
Check with Sudco.   
Title: Re: Mach II SS carb kits
Post by: farmerdl on November 11, 2022, 07:59:14 AM
They have had every Mikuni part I have ever needed.
Title: Re: Mach II SS carb kits
Post by: TMX_Maverick on November 14, 2022, 12:34:57 PM
Sudco won't have a "kit" for that specific VM17-18 carburetor, because it was a Bridgestone-modified carburetor (for lack of a better description). However, certain parts (certain gaskets, for instance) are the same as on the current VM18 carb shown on their web site documentation.
I called Sudco a couple weeks ago, and the rep who called me back couldn't find any cross-reference information to my general Bridgestone inquiry.
Your best bet (like mine) is to compare the exploded view of the VM17-18 carb (available in the part catalog downloads on this site) with the VM18 exploded view on Sudco's site, and order the parts you need that look "the same." YMMV
I'm about to take a gamble and buy the VM18 float valve and seat from Sudco, and hope it's the same as the VM17-18 Bridgestone version. (Fingers crossed)
Title: Re: Mach II SS carb kits
Post by: cknight on November 14, 2022, 01:01:21 PM
You might check with HVC Cycle in Lincoln, NE. They had carb floats for my 350GTR and some other fuel system related items.
Title: Re: Mach II SS carb kits
Post by: moonpup on November 14, 2022, 01:47:37 PM
https://www.ebay.com/itm/152876890682?epid=1426789056&hash=item23982c3a3a:g:F90AAOSwYEFhQLsE&amdata=enc%3AAQAHAAAAoDa3ikqBKnozFgURYcTw31LU3Y0PdTfGTm2z3byqG6NAr8%2BU1nfq6fxxkl%2FF%2BrlBA7%2BSnGg58wWiIxw3n9KupKfB9X2b8fUjVyg8QH7CAzgbJ9AZ30lAgeDn4Nr7ozkUbTGjrG%2FkvLA7jwaNDYpI38qNVl9jui7xExPUZ6OZjcIhDIWYFpUlZ1JubkYBxK36IWjLXBxPN7YEXjSsf2MGgpo%3D%7Ctkp%3ABk9SR-DJqfeOYQ
Title: Re: Mach II SS carb kits
Post by: OldSwartout on November 14, 2022, 04:55:04 PM
The Bridgestone carbs were modified by shortening the inlet horn to fit inside the side covers, however I believe the internals were identical to the normal VM18.
Title: Re: Mach II SS carb kits
Post by: TMX_Maverick on November 15, 2022, 12:44:54 PM
The Bridgestone carbs were modified by shortening the inlet horn to fit inside the side covers, however I believe the internals were identical to the normal VM18.

Thanks; I'm hoping that's true for the parts that Motogary and I need. There are visible differences when comparing exploded assembly views, though. Obviously the top slide cap is different on the Bridgestone's VM17-18 (for two cables, instead of the VM18's single cable and separate lever-operated "starter plunger"), and the needle jet looks different. The BS VM17-18 has the oil-injection port, and the float bowls (and therefore float-bowl gaskets) are different. The float, washers, springs, and (maybe) the needle valve assembly look the same. I copied a post from (the original) member disc_valve, around 2015, which suggested that the internal thread sizes may be different than current carbs, so that could throw a wrench in the works.
Makes things exciting!

Title: Re: Mach II SS carb kits
Post by: OldSwartout on November 18, 2022, 09:40:31 AM
I forgot about the change over the years that Mikuni made that affected several of their models.  If you search here, there are suggestions to use the later parts.  I believe the biggest issue was the idle jet.  Someone else may remember other issues; if so, please post.