Mikuni Carbs

[Vince Lupo]

Hello -- Has anyone out there had any experience fitting Mikuni carbs on a CB77? I'm in the process of investigating this option and would like to know what kind of trouble (or not?) I might be asking for if I follow through down this road. Right now the 'specialist' at Sudco has informed me (my mechanic, actually) that he'd be able to determine the best configuration as long as we provide him with the various measurements he requires. Sooo....we'll see what he comes up with and hopefully this won't cost too many jillions of dollars. Any suggestions would be most welcome! Thanks!

[kustommusic]

Vince, Ther was a discussion on that subject in the e-mailed newsletter. Mabey you could ask there. Steve Greer

[Vince Lupo]

Thanks for your reply, Steve. I e-mailed Michael Stoic regarding this newsletter, and hopefully he might have a copy of it. Is there some other place I should be looking for this newsletter????? Sorry, I'm not as much a veteran of this website as others are.....thanks!

[kustommusic]

Vince, I should have called it by it's correct name. It's the:" 305 mailing list". I think Mikale will know what your talking about though. you should just sign up, I did and there is alot of interesting info passed back and forth. Iv'e yet to contribute there but it's fun to read.Steve Greer

[Vince Lupo]

Hello Again -- well, we finally have some news on the ol' Mikuni carb situation. We managed (my mechanic managed with his brain and hands, I managed with my wallet, hence the collective 'we') to install 26mm Mikuni's to the 1966 CB77 beast. What needed to be done to accomplish this task was to have mounts custom-machined to be able to attach them to the engine -- apparently the new-fangled carbs don't attach the same way as the sensible ancient ones. The only thing that 'we' had to watch was the petcock, and the mount on that side had to be made in such a way so that that carb wouldn't hit the petcock. Other than that, the only other thing is that now I have two separate choke levers to deal with, but the bike is now 99.9999% complete -- just the jetting has to be sorted out a little bit - and that's something 'he's' doing and not 'we'. So, bottom line, it can be done depending upon your level of expertise or the thickness of your wallet - or level of irrationality!

[wombat200]

Curious as to the outcome of this?? I have a few 26mm Mikunis lying around, may be worth considering if the performance warrants it??

[Vince Lupo]

Well -- It seemed that things were progressing in a good direction. HOWEVER, things have not worked out as hoped. The bike worked fine up to about 1/4 throttle, and then it would break up. The best that could be obtained was approximately the same performance as the Keihin's, but with some hesitation here and there. Apparently, Keihin and Mikuni measure the internals of their carbs differently (Keihin by flow and Mikuni by actual diameter of the hole), and we haven't been able to properly cross-reference the measurements of the needles, nozzles, jets, slides, etc. Plus, SUDCO, the Mikuni supplier in the U.S, has not been very helpful. I think they are reluctant to give out any information for either fear of liability issues or they don't know the answers because they don't have an 'off the shelf' application for the CB77 -- either way, they only seem interested in selling carbs and not hearing from you again. So, the Keihins are back on the bike. What I need to find is someone who races this stuff (any Team Obsolete folks out there???) and who knows the magic formula to go from Keihin to Mikuni. Both are 26mm, and everything else (air filter, engine internals) is stock. The only addition is the electronic ignition. Any suggestions out there??????