Stromberg MB1 carb-good for anything or is it a paperweight?

[Bill Dizer]

I have a friend who is offering me the major parts of a Stromberg MB1 carb. It is not complete. It is missing the choke swivel part, it is missing a cap of some type over the center of the float cover, and there is an open port on the upper side of the carb, near the throttle shaft. The mounting is vertical with a horizontal throttle shaft, with the throttle stop screws on a small attachment, but no throttle lever to attach a throttle rod. It is a decent looking carb, looking rebuilt. I have not taken anything apart since I don't own it. The fuel line appears to go in the center of the base of the float bowl, but there is no elbow or anything to attach it to. I do not have anything that I would adapt it to because I just have two stock T's! Looking for information as to usability, parts availability, etc. It is a brass or bronze body that is very clean. I will try a photo post but have never had any luck! Tried photo,,said it was too wide and too high, by a lot, and since this is an iPad Air two I have no idea if or how to change it!

[Mark Gregush]

Float bowl cover nut are pretty much the same on the Strombergs.
viewtopic.php?f=5&t=199
The open port next to the throttle could be the vacuum port for vacuum fuel pump.

[BuddyTheRoadster]

I would pick it up if I were you. The MB-1 is a rare Stromberg and apparently popular with the Fronty guys as you can mount it directly to the head. A choke butterfly wouldn't be hard to fabricate, the cap over the float needle C in the diagram is often missing and can be made, and if you're missing the angled plug just above the throttle butterfly, a grub screw will do: that's where you'd tap vacuum to run the vacuum tank. If you're missing the idle needles A and B, that would be more concerning.

Even if it won't suit your needs, one of the speedster guys will be interested.

[Tim Williams]

The MB's run good with the Frontenac head.

Tim

[Bill Dizer]

Thanks for the information, it's a big help. I am buying the carb just to get it back in circulation! I will be watching for the top bowl nut, and a choke assembly, if anyone knows of those! I will post in parts forum! I need to find a way to post photos. I don't have anything to run it on so it will be moving on!

[Scott_Conger]

I make those Float bowl nuts. Two photos showing comparison of mine vs original:

[StanHowe]

MB-1s are fairly popular on Speedsters. Ralph Ricks swore by them on his Great Race car. They were stock carbs on Cleveland and several others. Simple carb with no economizer but with an accelerating well/venturi.

I sell a couple a year if I have them to speedster guys. I have two on the bench right now I thought were going to be done this week. Didn't happen.

Without some photos to see what is missing I'm not only not a buyer but also not an appraiser.

They are neither terribly rare or valuable, especially if parts are missing.

I'm with Scott. I make those float caps by the handful. Piece of 1/2 260 brass hex, drill it, tap it 1/2 24, part it off, diameter reduce the side and taper the end. Clean up any tool marks, run it over the sander, throw it in the drawer. I dunno how many I've made but it has to be in the hundreds. About the only thing I use 1/2 inch hex 260 for. Missing from probably 75% of the Stromberg at least. I also make the early style for the cast brass float bowl covers. Not much demand for them.

[Bill Dizer]

Thanks again for the information and help! I am ordering the bowl cover nut from Scott. I am keeping an eye open for the choke assembly and the fuel inlet bolt and banjo. As I said, I am planning to move this on to the next deserving user, and having no idea what a mostly complete carb is worth, I am hesitant to sink a fortune in it! Not trying to make much of anything on it but would prefer not to lose much either! I am still trying to figure the photo problem out.