Message For Ed Chesnut…

[viclioce]

Hey Ed! I think I got a bad trade here. I traded a highly sought after Super Rat kill switch for a 94 Wombat carb.

However, the needle jet has no shroud so it turns out I got sent a VM24 SH-83A not a 83B. Is this really just a paper weight? Can anything be done with it besides DO NOT USE IT?

I’ve left a message for my friend with whom I traded to call me. But if it really isn’t usable I’ll have to send it back to him.

[Bullfrog]

I'll put it this way . . . even Harry Taylor threw up his hands after multiple attempts to tune the jetting of the 83A to run properly on a Wombat.

Ed

[MTrat]

I have a 'paper weight' mikuni. Surely most of the parts must be useable?

[Bullfrog]

I don't know if "most" is the correct adjective, but yes, some of the parts from the 83A are useable in other carbs.

Ed

[viclioce]

Well that’s what I thought. Yes, just about everything is useable in an 83B except the carb body and the needle jet tube from the 83A carb. So he has an 83B he will send me. Victor

[scmark]

How do you tell the difference between the 83A and 83B carbs. I picked up an ACE 100 with a reed valve manifold and what looks to be a Wombat VM24 carb. Before I get too deep it would be nice to know which one I have to not waste time and $$$.

[dirty_rat]

Here is a photo Ed put into his article on Mikuni carburetors in the Resonator Revisited magazine (Issues V:1-3 and V:1-9).
It makes it easy to tell the two apart by looking down the throat. The “A” carb does not have the brass
shroud sticking up into the carb throat.
Hope this helps.

[scmark]

Thanks. I will check it out when I get home from this job thing I still go to.

[viclioce]

There is also a VM 24mm in the 93x Super Rats. It has a lever choke instead of the pull button choke. Make sure you get the carb correctly identified. Victor

[taber hodaka]

I would not use the 83A carb or a 22 on a reeded ace 90 or 100. I would use a 24mm or larger. ------ Clarence

[scmark]

I did check. I have an 83B. The fun will be to get it jetted for the ACE 100. I have been tearing it down and have found some interesting things about it. It came with a reed valve manifold but DPO mod is that he never put in the boost ports or the windows in the intake side of the piston. Id did have a Super Rat Piston and head on it though.

[Bullfrog]

No reeds either? In which case, it was just a switch from a round passage intake manifold to a rectangular passage intake manifold which was capable of accepting the larger carb.
Ed

[scmark]

Actually it did have reeds. They were warped and wouldn't seal the backflow. See the pictures. This was done by a guy that was AHRMA road racing.

[Bullfrog]

Well, that IS odd.
Ed

[taber hodaka]

Turn them over just kidding. Clarence