Topic: '71 836 kit smoothbore fitment issues

[klp]

Not sure where to start here but I am struggling getting the carbs to fit on this bike. It was modded back in the day with the entire catalogue. Cam of some sort, 836 kit, dyna, smoothbores, Kerker with zero baffles, different coils and fancy shocks. I know how much everyone loves pics - I will get some later I promise.

When I got my hands on it the 2 and 3 carb boots were mounted backwards and when the carbs came off it looked like a funhouse - none of the boots lined up. If I line it up so they are all straight the spacing is way off. The head spigots are 36mm and the carb throats are 34.

I bought some 4into1 boots and they seem to present the same issues. Over the length of the rack the boots seem short by 1/8". That I think I can deal with the real issue is spacing between the carbies. With the boots aligned like they should be 1 and 2 carbs are off by like 1/4".

I will go out now and measure carb center spacing.

[MauiK3]

Is the rack stock? Seems like it couldn't be.

[seanbarney41]

As far as I know, you need special carb boots to mount vm29s.  They are shaped different to correct the spacing.  I don't know if new ones can be obtained, especially after the re-organization of Sudco.  I have at least one set.  I know there are other members here who have them.  I don't think I would sell mine.

[klp]

OK with my crude measuring calipers I seem to have 77mm centerline on the outboard carbs and 98 or so in between 2 and 3. I think I have the wrong rack - wondering if maybe these are racked for a z1 Kawi.

Does anyone know if these carbs will fit in a oem 750 rack?

[seanbarney41]

I think all 29 smoothies were spaced for the Kawi's.  That is why you need the special adapter boots.  I have heard rumors of some specially racked for cb750 but have never actually seen them.

[klp]

Pic as promised. Thanks for all who replied, unobtanium boots and I am good to go it seems.

[seanbarney41]

Wow...lots of cool old parts there.  I have not seen Smoothies with that elaborate fuel rail/ feed set up...ensuring ALL the gas is there for the voracious sucking!  Put up a pic of what boots you have.

[seanbarney41]

Also, member here Don R. has recently bought a set.  I am surprised he has not  yet chimed in here.  Anyway, he may be willing to share how he found a new set.  Also a want ad in the high performance/racing forum may get you some.  If that does not work, hit me back up, that bike deserves some more vintage hipo goodies.

[seanbarney41]

And one last thing!   Guard that Kerker emblem with your life.  They tend to want to fall off when least expected, rendering that beautiful pipe a lot less beautiful and those old emblems are impossible to get.  Don't ask me how I know!

[Don R]

 I got a set of carb isolators from Z1 Enterprises but it may have been the last or next to last set. They are the rubber ones.
 I already had a set of UPP brand carb insulators sold by Sudco, I believe they are polyurethane. I have carbs for both of my sets though. I've also not seen the elaborate fuel feed lines on those 29's and one of my sets was on a GS1100e four valve engine. I'm thinking backwards Honda 2-3 rubbers can work on the ends but not the middle.

[Don R]

 These are the good ones but sold out since I got mine a couple years ago.
https://andrewsmotorsports.mybigcommerce.com/honda-cb750k1-k5-cb750-76-cb750f76-cb750-sohc-vm29-manifold-kit-005-026/

 If Andrews could get UPP to make some I'd buy another set. I prefer the urethane ones, who knows maybe they were 3D printed? There might be one or two more of us that would buy a set.
  Z1 Ent. does have other VM29 parts listed.

[newday777]

Pic as promised. Thanks for all who replied, unobtanium boots and I am good to go it seems.

Very cool parts.

[klp]

Thanks again to everyone! I have reached out to Z1, fingers crossed. The fuel delivery system is wild - I am thinking it was more for show as I can't imagine it was starved for fuel. The feed lines did run well below the bowls though so maybe they had issues. I plan to just sweeten up the routing with new lines/clips and call it good.

I will get some intake boot pics later, they seem oem as they are numbered but I don't know if they are from this bike originally.

[MauiK3]

Looks like a Kawasaki setup.

[klp]

Couple of pics of the boots that were on it originally. The 2 and 3 boots were mounted backwards but that wasn't much help for fitment.  They are 36mm on the head side, 34 on the carbs.

[Stev-o]

  I have not seen Smoothies with that elaborate fuel rail/ feed set up...

I have not seen a setup like that either, custom...

[BenelliSEI]

I got those manifolds for my Carlini Chopper Project. They worked properly. Nothing else would fit. Keep trying for them.

[Tim2005]

I'm interested in finding a solution to this too, I have a set of VM29s and a nice flowed early head to go on a 836 motor sometime

[Don R]

 I sent an inquiry to UPP to see if they are interested in making more of the urethane Sudco type 005.026 connectors, hopefully they still have the patterns and with sudco gone would be willing to make me/us a few sets.

 I can see it now, it's the Donco carb adapter, it's not a slicer, it's not a dicer, it's genuine plastic so don't accept imitations! Order soon and get two sets for double the price! Just add shipping! 

[Don R]

 Bill at UPP Racing e-Mailed me and said they can still make the carb adapters and there is no minimum order!
 Bill at UPP racing 541-832-2139    uppracing.com

[seanbarney41]

Don is a straight up hero!

[klp]

Well now that is great news! Thank you Don and everyone else who contributed.

[Medyo Bastos]

Yeah, too bad i sold off every set of vm29’s i owned


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[Don R]

 I also posted on the high perf section, Bill at UPP asked for application information since Sudco never told them what they are for. I listed what I believe to be right there.

[klp]

I reached out to Bill and he at first didn't know what parts I was referring too. I did not know he made them for Sudco. We eventually figured it out - he told me they are working on putting them on the website.

While it is not a no I was hoping he would ask for CC info and shipping address lol. I reached out to Z1 - they no longer have any.