86 VFR Carb rebuild.

Discussion in '1st & 2nd Generation 1983-1989' started by midias, Jul 28, 2014.

  1. midias

    midias New Member

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    Recently my 86 VFR 750 has started leaking a lot of gas while running. I thought it was the fuel Ts but it turned out to be a float bowl gasket. So now I have a couple of questions.

    After getting experience with my other V4 (82 Magna) I have learned a few things.

    1, The fuel Ts are weak and they can and will break. They are expensive to replace.

    2. The diaphragms can rip when the cover is removed. If the plunger has some drag when pushed up they are probably good.

    3. Syncing these carbs can suck.

    Now some questions.

    1. Would you bother removing the carbs from the pletnum to replace the fuel T o rings and take a chance breaking a hard to find part?

    2. Would you take off the diaphragm covers for inspection?
     
  2. squirrelman

    squirrelman Member

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    1. Remove plenum ONLY if fuel tube O-rings are leaking. Huge PIA ! :sour:

    2. No, cuz it's sometimes hard to get diaphrams reseated properly. To check if diaphrams are intact and slides are working, remove tank and air filter, see that both slides move equally in response to throttle movements. Or blow air into the elliptically-shaped holes in carb upper intake side.

    Tubes that are ready to break turn a lighter greyish color than the were originally. Dark is good, not fracture-prone.:eagerness:
     
  3. MiddleTBabb

    MiddleTBabb New Member

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    Agree with Mr. Man. Plenum and tube gaskets are...not easy to reinstall. If you can redo the float gaskets with the carb on the bike, its worth a shot. Im going to try this soon as well.
     
  4. Bernieswanson

    Bernieswanson New Member

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    Suspect T tube O rings first. That was my problem but jacked around with float bowls and other crap before I realized it was 15 cent o-rings.
     
  5. midias

    midias New Member

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    Got it all back together last night. I took them apart and off the manifold, replaced every O ring and bench synced them. I also replaced all the screws, thermostat and fuel filter.

    I found a nice universal duralast filter (FF3419DL) that fit so I could ditch the old EMGO one.

    Started ASAP and ran well, I adjusted the idle and it held steady at 1100 RPM. Carbs felt good, no flat spots or stumbling but then it started pouring so more testing soon.

    [​IMG]
     
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