Where to measure float xs1100 sg

[vedgar]

The carb body has a rib running the perimeter of the body base or you can call it where the the gasket seats. Should the float height measurement be from the top of the rib or the base of it ( flat surface) . I may be splitting hairs, but the difference is about .35 mm.
Vance

[bikerphil]

It shouldn't really matter, as long as you do them all the same way. I myself measure from the base.

[jetmechmarty]

It's the flat surface..

[MPittma100]

Float eight

If you use a dial caliper, the depth "foot" will sit right on the flat part of the carburetor body. I also measure from here.

The Yamaha manual gives you a variance to set the height. You have a minimum and a maximum rather than an exact number - i.e. 25.7 + or - 1mm.

The raised line on the body is designed to keep the gasket from moving when the bowl screws are tightened. Measuring from the line or the flat does not matter. All floats do need to be set the same from either position.

MP

[bikerphil]

Plastic float setting (80-81) is 23mm.

[Schming]

Hi vedgar, here's a thread that may be of interest to you:

http://www.xs11.com/forum/showthread.php?t=41073

[natemoen]

The Yamaha manual gives you a variance to set the height. You have a minimum and a maximum rather than an exact number - i.e. 25.7 + or - 1mm.

That +/-1mm causes a big change in carb operation though!

[MPittma100]

Float Height

That +/-1mm causes a big change in carb operation though!

Interestingly, the spec for the newer floats is 23 + or - 0.5mm instead of + or - 1mm for the older floats?

Nathan, what performance change have you seen in the 1mm height difference? Which height performs best - higher or lower?

Mike

[natemoen]

Significantly richer to significantly leaner.

[mack]

Best way

[vedgar]

Thanks to all

Running great at idle and 1/4 throtttle up. Gotta figure the low end bog. May be a little lean , cause it is slow to warm up and gets better as it warms up.
Vance

[mikubuilder]

Just a suggestion, you wanna mess with carbs on a warm engine. ..hence the "fan at front of it" suggestions

[MPittma100]

ALL Four

Running great at idle and 1/4 throtttle up. Gotta figure the low end bog. May be a little lean , cause it is slow to warm up and gets better as it warms up.
Vance

Make sure all 4 pipes are hot during warm up. Check with heat gun, spray water bottle. If real brave, use the hot finger test. Some of these bikes are just that way. I have a 1980G that is stubborn when cold and a 1981H (with same jets) that warms up quickly and is ready to go?

MP

[vedgar]

better than box fan

Have a carpet cleaners (air mover) for tuning and keeping bike and me cool. It really puts out a good column of air. It is better than a box fan.

[Schming]

X2 I agree, but the level shown looks low, should be up to the body side of the gasket surface, might be just the pic.


I have found the rulers, digital calipers, etc. too cumbersome for accuracy so I made a gauge from an old gasket:





Just leave a BCH loose to account for the embossed bead on the gasket surface: