Airhead Mikuni Owners Thread

Discussion in 'Airheads' started by Uncle Pollo, Oct 2, 2012.

  1. blaine.hale

    blaine.hale Long timer

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    Man, if I could have just a solid piece running from the clam shell to the carb, i'd be a happy man. There's a whopping SIX hose clamps just to secure this set up. Definitely isn't pretty.
  2. Kai Ju

    Kai Ju Long timer

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    Here is a FWIW, despite SS's concerns.
    I'm running VM 38's using the stock intake rubbers in the front and the stock elbows in the back.
    The elbow is sealed inside the bellmouth, verified with propane.
    The jetting sure feels spot on and there seem to be no atomization issues with the elbow in the bellmouth.
    Mind you, I haven't tried it any other way, but the results speak for themselves.
    Better power and better mileage than the Bings. Easy starts, lighter throttle pull are a nice benefit as well.
  3. Airhead Wrangler

    Airhead Wrangler Long timer

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    [​IMG]

    As always real world results win out, but at least in theory, I'd agree with SS that there'd be reason to believe that sealing the intake runner on the inside of the carb mouth would affect airflow to the two air jets seen in the bottom right of the mouth. Keeping those unobstructed is critical to good atomization for both your idle and main circuits. I'd at least try another way to see if it makes a difference.
  4. Kai Ju

    Kai Ju Long timer

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    Look at where the openings are located, they are in about 2-3 mm from the ID surface. The stock elbow ID is bigger than the OD that would be described by the circle that the openings are in. Also, the bellmouth on the VM 38's is deeper than how far the elbow sticks into the bellmouth. (Man, I hope that made sense)

    The only way for me to try something different would be to get another set of elbows to play with. I don't want to be stuck with something that doesn't work as well, when I already have a solution that does. As you already pointed out, real worls results prevail.

    I'll gladly accept donations in the interest of furthering the knowledge base :D

    BTW, read your TDF thread last night, epic, awesome, jealous are just a few words that come to mind.
  5. supershaft

    supershaft because I can

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    I think I said that they seem to run alright like that but it is a concern of mine. I still think plumbing pipe reducers is the best route but that way works. I have just seen setups like that letting a lot of dirt in. I haven't seen pods letting a lot of dirt in but I sure have seen the stock clam shell and square airbox setups letting a lot of dirt in time and time again. Modified to fit and properly oiled K+N filters keep square airboxes spotless.
  6. Airhead Wrangler

    Airhead Wrangler Long timer

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    Um, no they don't. It's 58mm. Scratch that.
  7. blaine.hale

    blaine.hale Long timer

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    No update here yet. Still sorting out air leaks.
    So far, still running like garbage, richening and leaning the mixture has no effect because there are still air leaks to hunt down, duh.

    One of the reasons I'd like for that silicon elbow piece to work out :D

    Maybe I can render and print something with ABS.
  8. Kai Ju

    Kai Ju Long timer

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    Airleaks on the airbox side really shouldn't influence the way the bike runs, unless they are massive.
    Airleaks on the engine side on the other hand will completely mess with your metering.
    Please verify that the instake stubs are tight and sealed to the head before you waste a whole bunch of time trying to jet the carbs.
  9. blaine.hale

    blaine.hale Long timer

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    That's what I'm currently doing. I went with the stock intake rubber there and just clamped it down a lot on the mikuni...that's probably causing mega leaks. I really need to do what Airhead Wrangler did and size that tube down with another, smaller one for a snug fit.
  10. Kai Ju

    Kai Ju Long timer

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    so you're obviously not running 38s, are you ?
    The 38s are essentially the same size as the 32 Bings.
  11. blaine.hale

    blaine.hale Long timer

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    34s. Vurrry loose in the intake boot so I had to clamp down pretty far. Definitely potential for a leak.
  12. Kt-88

    Kt-88 I like everything.

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    I'm running 32s and my bing hoses do just fine, no leaks. Of course, they are brand new, if that matters?
  13. blaine.hale

    blaine.hale Long timer

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    According to the carb cleaner AND propane test, I'm leak proof everywhere.
    Hmmm. Sure wish these Mikunis had a place for me to hook up my balancer.
  14. supershaft

    supershaft because I can

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    I would put a vacuum take off on them before I installed them. I did on my Dellorto's. Dellorto's have a very handy unused mixture screw boss to turn into a VTO. Maybe those Mikuni's have something similar? Bing and Dellorto make VTO kits.
  15. Kai Ju

    Kai Ju Long timer

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    Me too, on the vacuum pick ups. I'm going to figure something out tho.
    Both carbs are the same and there is a lot of acreage on the left side that could accommodate a vacuum port. That will make it easy access on the left but a bit of a pain on the right. I'll let you know what I come up with.
  16. blaine.hale

    blaine.hale Long timer

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  17. SVARTH

    SVARTH reset and go further

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    Hi there...

    sorry to bother,

    I have a pair of 38 cv Mikunis off my 900ss Duc (i replaced them with Keihins..:evil) and I am thinking to use them on my 100gs PD.....

    has anyone tried this conversion (CV mik not VM...)

    thanks

    and fly low...
  18. Kt-88

    Kt-88 I like everything.

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    Well, now my results will be useless for anybody. I am now using R100 pistons and cylinders on r90 heads, with vm32s.


    This is a pretty unlikely setup.
  19. Kai Ju

    Kai Ju Long timer

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    How does it run ?
  20. Kt-88

    Kt-88 I like everything.

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    Well, I'll let you know today. So far fantastic but that's less than a mile of testing.