Hello, I'm having trouble setting the float level on my mikuni carb. The carb is off a 1985 yz 250. See attached picture. According to the clymer book I have, the float should be set at 27.0 mm.

1. Keihin Carburetor Manual

The book says to 'Measure the height of the float arm above the carburetor body without the float bowl gasket. Hold the carburetor so the float arm tang is just touching the float needle-not pushing it down.' Also according to the book the model # of the carb is 'VM38SS' The trouble i'm having is that when I set the level @ the specified 27 mm; I don't get any gas when installed. I'm confused as to where exactly to take the measurement from. The measurement from the carb body to the center-line of the pin holding the float is only 21.2 mm; therefore, when set at 27mm the float arm is at a heavy incline and not even close to level.

Any help on this would be greatly appreciated. I snapped a couple more pictures of the carb. Zoomed out view to see the overall style of the carb. Oddly enough, my intake/exhaust ports seems to be reversed compared to the VM manual. The difference between the very top of the carb intake and the bottom of the carb body is about 3 mm. I've been measuring from the carb body so adding the 3 mm I should be in a range of 20 - 23 mm to top of float.

Even after adding the 3mm my floats still bottom out on the carb body. I noticed that the little 'plate' appears to have been cut/modified.showed this in the last picture. Can you tell me what purpose this little plate serves? This has really frustrated me so I really appreciate any and all help.

Thanks for the replies! Trane xb80 service manual.

Keihin Carburetor Manual

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