GSX-R 750 Pictures of how I adjusted the carburetors float bowl height on my 1985 1986 1987 Suzuki GSX-R750 motorcycle.

The crankcase was filling with fuel. Oil smelled like fuel, more oil when I drained it than when I filled it, Oil was thin and not lubricating properly. Bad news.

I figure the floats must not be closing properly. This lets more fuel into the carbs after they are already full. The excess fuel spills into the cylinder, drains past the rings, and into the crankcase.

So I pulled the carbs, removed the float bowl covers, dumped the remaining gas into my lap, cursed and screamed and took a shower, and then went about setting the float height and ensuring proper operation and seating of the float "needle valve."

But first, lets pay some bills:

  1. First I GENTLY and CAREFULLY drove out the float bowl pivot pin with a drift and hammer.

  2. From left to right this is the needle valve seat, needle valve seat retainer screw, float, and needle valve. Then there is the pikot screw et cetera, but screw that.

    I cleaned the needle valve with carb cleaner and a rag. One needle had a sticky spring, so I soaked that one in carb cleaner overnight and that seemed to do the trick.
    Exploded carb view

  3. I put it back together and measured float height using the piece that sticks out the bottom of the calipers. Cool trick I saw on Helpful site. I measure from lip of carb bowl to top of float.
    Measure Float Height     Measure Float Height

  4. I made small adjustments to the height by bending the little metal tab on the float that contacts the needle valve. I held the float with one needle nose and pushed on the tab with the other. I did not want to hold the float and push on the tab because those little arms that connect the floats look old and brittle. and cracked. and already broken in places. And one of them is brand new and freakin expensive. SHUT UP!
    float tab adjust

  5. That looks like 14.6 mm to me.
    14.6 mm

  6. Next I sold out to make 02ยข so I can fulfill my lifelong dream of owning a 1986 944 with blown head gaskets.

    But no minivans!

  7. Then I finished my beer.

All 5 pages dissecting carbs:

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