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Discussion Starter #1
Can anyone tell me the center to center distance of the mounting holes of the carb mounting flange?

Don't have my parts or bike nearby to measure it myself.

Thanks.

jb

 

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Discussion Starter #3
Not center to center but edge to edge = 2 7/16 "
Thanks, Tony.

2.4375in = 61.912mm

I think the holes are 8mm in diameter, but am not sure. If I subtract 4mm from each side I should get the approx. the center to center distance.

62 - 8 = 54mm

Not exactly the number I was hoping for, but it will give me something to go by.

I'm hoping to find a plug and play solution for that BW carb...still not liking the duct tape. ;)

jb
 

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If you click on the picture to magnify it you can see the white lines I drew. The measurement is right edge to right edge which should equal center to center.

I did it again in metric. This time it is left edge to left edge.

The left side is 51mm. The right hole measured to the left edge of the hole is 113mm. 113-51=62mm. Left edge to left edge, or center to center.

P4251301.JPG

The bolt hole looks to be 6mm.

P4251303.JPG

I even stuck a 1/4" bolt in the hole for reference .

P4251302 (2).JPG

I just finished painting the under side of my XT350 tank and it came out pretty bad but who cares? Plus it is raining -- can't believe rain at this late date. Oh well......Tony
 

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Discussion Starter #5
...left edge of the hole is 113mm. 113-51=62mm. Left edge to left edge, or center to center.
Tony
Thanks Tony,

That makes me a little more hopeful for a bolt-on solution, other than the stock TW flange.

There is a flange for the Mikuni that the holes are 60mm on center...may be close enough... but may not even be necessary.

Just trying to find all the options.

jb
 

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I have a 2JX mounting flange here. The holes themselves measure .275 inches, not quite 8MM. Center to center measures 2.425 inches or about 62MM.

The metal face to the engine measures 1.10 inches or 23MM. O ring inside is 1.390- 35MM and outside is 1.560 - 39MM.

Carb side rubber opening is 1.30 inches or 34MM. Keep in mind this is a used old style carb mounting flange.

GaryL
 

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Discussion Starter #7
Thanks, Gary,

I'm just gathering info to determine if there are existing ready-made parts that will work to mount the Chinese Mikuni carb to the TW without modification.

It may turn out to be a dead end, or my curiosity about things mechanical may kill me first. ;)

jb
 

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You might contact Macbig2k1 in Germany.
Very knowledgeable Guy.
 

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Thanks, Gary,

I'm just gathering info to determine if there are existing ready-made parts that will work to mount the Chinese Mikuni carb to the TW without modification.

It may turn out to be a dead end, or my curiosity about things mechanical may kill me first. ;)

jb
Yeah JB, you and I went to different schools together and I know what you are thinking. Old and new style TW carbs take different boots and I would bet there are other bikes in the Yamaha line up that might have just the right boots for this application. Finding the real specs of all the various mounting flanges and boots could be a hard search unless you have the parts right in front of you. Go on eBay and you might find friendly sellers with various flanges and boots willing to do the simple measures we need.

GaryL
 

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Not sure if this helps but the top two here fit the tw. 60mm hole to hole. I purchased the second one because of the larger intake than stock on my pumper carb. I got it when I was working at cycle gear so it only cost me $12 but I'm sure you can find something similar elsewhere or order this one from any bike shop.

 

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Discussion Starter #11 (Edited)
Not sure if this helps but the top two here fit the tw. 60mm hole to hole...[/QUOTE]

Thanks PSC,

It's good to know that the 60mm center to center will fit.

They are more common than the 62mm, although I found 2 Mikuni flanges that turned out to be the same as the one on the TK CV carb. They aren't of any benefit since the Chinese carb's manifold diameter is 2mm larger. Might as well keep the stock manifold.

I followed your TW build (and Mr. Bracket's) experiments with different carbs with great interest.

The objective here is not to find a high performance alternative to the stock carb, but to find a low cost, bolt-on solution that will perform adequately for those with carb problems who can't afford (or don't want to pay for) a new TK.

CNC200 has the alternate carb working, but I would prefer a less "cobbled together" look.

Thanks for the input, and I would appreciate any insight you have gained from your carb experiments.

jb
 
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