Can anyone identify this carburetor?

[traderyoda]

Greetings all,

I have a 1970 vintage ETS 250/1 G5 motor with a carburetor I cannot identify. It's BVF and stamped 30M4G and is in very good condition overall. It similar to a 30KN but it has what I understand is a starter jet port (which has no mechanism attached), does not have a choke, and has a different cap. I'd like to know more about it and understand how to adjust it and find jets should I need them to tune it. The motor is installed in a Rickman frame. I've attached some pictures below. Many thanks for your guidance and advice!

[Puffs]

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[traderyoda]

Puffs - thanks! Yes, BVF is stamped on the body and the float chamber. Fortunately there are no missing parts, except for that open port which I understand is a starter jet port. It was like this when I purchased the project and can't tell whether someone removed a part of it was always like that. I've seen later carbs from BVF with a similar port but never one with a side float. Not clear why you'd need a tickler and a starter jet.

Appreciate the tip about Jikov carbs - closest thing I've found so for to this carb. I suppose it's perfectly feasible that BVF made carbs for Eastern Bloc consumption either making the design of other manufacturers or having others build units they designed. Your tip led me to http://cvkustoms.com which has a ton of info on Jikov and other Russian carbs.

The bike is historically significant and I need to preserve it. I won't be racing it but I do want to get it running. The engine was hand-built for U.S. motorcycle racing by the MZ factory and shipped to England to be placed in a Rickman frame. The paperwork from the MZ factory lists it as a 1970 MZ ETS250/1 which it their ISDT motor, but it's ported differently and has this larger 30mm carburetor.

[traderyoda]

So the mystery hole is for a "starting piston" (Startkolben)... which I assume is a spring loaded primer with a plunger you push to give the motor a couple of shots of fuel before kicking it over. I see these on other BVF carbs, but never on one of the older side float units. Anyone know if these starter piston things were a common size? Wondering is something newer fits something older... a long shot I know.

[Puffs]

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[breakwellmz]

So the mystery hole is for a "starting piston" (Startkolben)... which I assume is a spring loaded primer with a plunger you push to give the motor a couple of shots of fuel before kicking it over. I see these on other BVF carbs, but never on one of the older side float units. Anyone know if these starter piston things were a common size? Wondering is something newer fits something older... a long shot I know.

Hi.

This is your unique Rickman MZ i assume? It`s about time for a full bike photo of this bike!

Cheers

[traderyoda]

Sure thing!

[traderyoda]

Puffs - yep, I going to try and breath life into this vergaser. As I mentioned, I cannot find any side float BVF carbs like this on any MZ or any other motorcycle... at least not yet. The closest I've found was the lead to Jikov carbs but they do not have a starter jet either. Perhaps this carb wasn't on a motorcycle at all and was used in a car.

Clearly the gaping hole where the starter jet should be needs to be either filled with the correct parts or sealed off. On this front I have no idea how the bike was equipped since whoever had it before me monkeyed with it and there's no way to tell. One hint is that I believe the starter jet is cable operated and there are no indications of anything other that a throttle cable running to the carb.

What do you think of just sealing off this port? From what I can tell MZ's around this time with side float BVF carbs didn't have starter jets. The factory equipped this with a larger 30mm carb probably to match the tuning and porting they did on the barrel. It might have had just a rubber stopper over the port - it would be easy to make it so without damaging anything.

[breakwellmz]

Hi.
Thank you, it looks lovely!
I would be surprised a bike of this type and era would have a plunger type enrichener let alone a cable operated one. I would expect a simple `tickler` that holds the float down to give a rich mixture for cold starting like i had on old Jawas and CZs with Jikov carbs.
Keep up the good work!
Cheers.

[Blurredman]

I would maybe say it could be from the RT125, but those inlet/outlets look pretty big!

[Puffs]

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[traderyoda]

The fact that is has both a tickler and a starter jet suggests to me that it was probably not from a motorcycle. I did search around for Trabant and other autos of the period but didn't find a match, but early models did use side-float carbs. I can only imagine the amount of tinkering that must has went on back then. Today, if engine doesn't start with the touch of the key I get miffed.

The idea that having both a tickler (for the mechanic) and cable-operated starter (for the driver) makes perfect sense and lends credence to this not being a motorcycle carb.

I agree that it's likely the starter jet was never used on this machine, so I'm going to go ahead and seal it tight with a rubber plug.

You folks have been enormously helpful - thanks so much for your advice on this. I've got a long way to go getting this machine back together, but it's all there and just requires a lot of polishing and rebuilding of the carb and dynamo. I'll post progress and pics as I move along.

[Guesi]

I already put the questions of traderyoda on the german MZ Forum.
But no answer yet.
I have never seen this carburetor before.
I own an ETS 250/G, but my engine has a different carb.
It is a 30 mm carb. but different to the one that is asked for.

Here is a manual of the ETS/G. Maybe this can help.

[Blurredman]

Gucci, can I add that to my ftp ?

[Puffs]

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