Author Topic: Mikuni BS-29 CV  (Read 9900 times)

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aquaholic

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on: August 25, 2013, 11:59:19 am
HI

I'm having trouble getting the float height setting for this carb.  Anyone know what it is.

Thanks


DanB

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Reply #1 on: August 25, 2013, 05:00:25 pm
The spec is in the owners manual. I don't have it at the moment, but believe its 17 or 19 mm. Honestly, between those two numbers and the carb runs nicely, IMHO. What's the problem?
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tooseevee

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Reply #2 on: August 25, 2013, 06:14:20 pm
The spec is in the owners manual. I don't have it at the moment, but believe its 17 or 19 mm. Honestly, between those two numbers and the carb runs nicely, IMHO. What's the problem?

            I've sure never found it in the owner's manual that I have.

             It's not in Pete Snidal's Service Manual either. He goes through the BS-29 (except for a good exploded view) pretty well, but never mentions a float level height.

              I've never found it anywhere & if you want good tuning info on BS-29s you've gotta Google Suzuki or another that used these carbs back in the '80s. And read all other Mikuni BS CV sites you can find online. I've never found ANYthing on BS-29 specific to Royal Enfield except some useless mixture screw info mentioned in the Owner's Manual. Maybe the Factory Manual has it, but I don't have one.

          There's also a lot of BAD info on BS carbs in a lot of the online forums. Mostly involving the mixture screw & which way is rich, which way is lean.

           Aquaholic - Why do you believe your float is a problem?
RI USA '08 Black AVL Classic.9.8:1 ACEhead/manifold/canister. TM32/Open bottle/hot tube removed. Pertronix Coil. Fed mandates removed. Gr.TCI. Bobber seat. Battery in right side case. Decomp&all doodads removed. '30s Lucas taillight/7" visored headlight. Much blackout & wire/electrical upgrades.


DanB

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Reply #3 on: August 25, 2013, 08:36:45 pm
Your right 2CV. It's not in the owners; it's in the factory manual. 17.1mm is the factory spec.
Suppose I were an idiot, and suppose I were a member of Congress; but I repeat myself. ... Mark Twain
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tooseevee

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Reply #4 on: August 25, 2013, 11:43:41 pm
Your right 2CV. It's not in the owners; it's in the factory manual. 17.1mm is the factory spec.

             Thanks for that  :) At last I know. I haven't had any float issues yet, but might some day.
RI USA '08 Black AVL Classic.9.8:1 ACEhead/manifold/canister. TM32/Open bottle/hot tube removed. Pertronix Coil. Fed mandates removed. Gr.TCI. Bobber seat. Battery in right side case. Decomp&all doodads removed. '30s Lucas taillight/7" visored headlight. Much blackout & wire/electrical upgrades.


Superchuck

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Reply #5 on: August 27, 2013, 02:35:14 am
How do you adjust float height, and when do you need to?  If experiencing 'running out of gas' issues at full throttle?


t120rbullet

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Reply #6 on: August 27, 2013, 03:31:03 am
How do you adjust float height, and when do you need to?  If experiencing 'running out of gas' issues at full throttle?

I would check to see if you are getting enough flow out of the petcock before I started messing with the carb.

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Superchuck

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Reply #7 on: August 27, 2013, 05:06:19 am
Not having this issue... just curious.


D the D

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Reply #8 on: August 27, 2013, 06:14:52 am
How do you adjust float height, and when do you need to?  If experiencing 'running out of gas' issues at full throttle?

If the bike has been running fine then develops a problem due to floats, it is usually flooding conditions caused by deteriorating floats getting waterlogged with gas, falling apart, or developing holes in the can type.  The floats then don't float as high and the needle/seat deliver too much fuel before closing.
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palawan

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Reply #9 on: April 22, 2014, 05:21:29 am
I have UCAL-Mikuni BS29 on a Bajaj Rouser 200. Fuel spilled out from the overflow after a local "mechanic" adjusted my carb, and my readjusting the float level stopped the overflow. How is the 17.1mm measured? Is the factory manual mentioned available online? Jon in Palawan, Philippines
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DanB

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Reply #10 on: April 23, 2014, 12:10:35 am
Welcome Jon.

There's lots of good visual examples on YouTube. Search for Mikuni and float adjustment. Find one that is close to the BS29. There is not a perfect match for the carb, but the concept is the same.

Are you sure your float is not leaking?
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palawan

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Reply #11 on: April 23, 2014, 04:16:56 am
I shake the float and no liquid is inside. I'm pretty sure the mechanic incorrectly set the float level, and I want to put it back where it belongs.


tooseevee

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Reply #12 on: April 24, 2014, 01:31:09 pm
I shake the float and no liquid is inside. I'm pretty sure the mechanic incorrectly set the float level, and I want to put it back where it belongs.

           Watch 5 or 6 of these Youtube videos & they will help your confidence. All the videos for BS series CV carbs are similar to your BS-29:

            http://www.youtube.com/watch?v=0ogUMEpKERM

            You won't find hardly anything on the BS-29 specifically, but the other BS CVs are pretty much the same. It seems to be an orphan carb that was only put on a few bikes including the AVL Royal Enfields to get them to pass U.S. Federal emissions by starving the engine.   
RI USA '08 Black AVL Classic.9.8:1 ACEhead/manifold/canister. TM32/Open bottle/hot tube removed. Pertronix Coil. Fed mandates removed. Gr.TCI. Bobber seat. Battery in right side case. Decomp&all doodads removed. '30s Lucas taillight/7" visored headlight. Much blackout & wire/electrical upgrades.


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Reply #13 on: April 24, 2014, 02:39:57 pm
The reason you don't find much about this carb is because it is a UCAL BS29. It is a knock-off of a Mikuni carb, much like the Mikarb is on the Iron Barrel models.
Do a search for UCAL BS29.
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