81 GS450E - How/Where to Measure Float Height?

[pete]

Guys, I am completely confused.

Carbs are freshly cleaned and mostly back together, but I'm having no joy in getting the float height set correctly as per the spec's.

They should be set between 21.4mm and 23.4mm from the gasket surface with no gasket.

However, at what part of the float or float arm do I actually do the measurement?

The only information I can find so far indicates to me I should be measuring at the top of the float, but this just doesn't seem to be right when actually measuring.

I bent the tang on the left carb tonight to try to get closer to 22mm, got it to 24mm, and the floats are getting quite close to the carb body. If I compress the needle spring, they contact the carb body. That just doesn't seem right.

This is how I'm doing it now with my fabricated measurement tool. It's not spectacular, but it should do the job. It won't measure 0.4mm of course, but if I can get around 22mm I'll be happy.



So, can anyone shed any light on either what I'm doing wrong or if there's something I'm missing? I don't have much hair but I'm ripping what's left out rapidly here...

[Steve]

Keep your hair, you're doing a fine job.

.

[pete]

Cheers Steve, I'm trying anyway...

[bluewool]

Hey Pete,

I went through this last summer. It's a pain. To confirm heights when I was completed I fabricated an external gauge by drilling out an old float drain plug and attaching some clear tubing to it. With the carbs level I filled them with rubbing alcohol and held the tubing to the edge of the float bowl to confirm the correct level. It was nice to have the confirmation, although it was a further pita. 1 carb at a time..

[pete]

Cheers Bluewool, that's a pretty cool idea actually.

If I knew where to measure mine I could put that into use too...

[pete]

Just remembered I downloaded the Mikuni 1977 - 1988 VM Carb Guide from somewhere quite a while ago, and I found the attached diagram on page 85.

So, I guess this answers my "where to measure" question, however I'm still concerned with them touching the carb body with the needle jet spring fully compressed.

Any comments on that?

Also, given these are BS34SS carbs, the 22 - 24mm height specified in the table indicates that I'm at the high side of the tolerance right now and I should drop them another mm.

[SVSooke]

You are over thinking this buddy.You are in spec,it's fine.

[pete]

You are over thinking this buddy.You are in spec,it's fine.

It ain't the first time I've heard those words! I do tend to over think things sometimes...

I'll get them both to 23mm and be done with it