Need help for Float height on Mikuni Carbs

[Tweeker]

On my 1981 GS450T It says float height is 22.4 +/- 1.0mm . But when I try to get them to that height , the float bottoms out.

I am measuring to top of float and from the gasket seat with the gasket removed just as the spring pin in the float needle starts to move.

I have them off the bike and turned upside down.

Any help will be greatly appreciated. I have no manual , so I am relying on any info from you guys/gals. I hope someone has this info.

Thanks for your time.

[Ghostgs1]

Are you measuring to the top of the float, as you look at it upside down? Sounds like you may be looking at the underside, which would make the float set way too low. Ray

[Tweeker]

Can I post a picture on how I am measuring it? I could label the float so I know which point to measure from.

[Tweeker]

I am measuring from point "A" , should I be measuring from point "B" , which is the bottom of the float?

[BassCliff]

Check it out

Hi Mr. tweeker,

See it this info helps:

http://members.dslextreme.com/users/bikecliff/images/carbspec_float_height.html

Thank you for your indulgence,

BassCliff

[Tweeker]

In my thumbnail , I have inserted the letter "A" and Letter "B".

Frim the link you sent me, it looks like I should be measuring from Letter "A" to the gasket seat minus the gasket.

But when I try to get 23 mm it seems to bottom out the float.

I have included another picture to show what is happening. On the left side of the Photo, that is a brand new float I never measured but just bent tab down for theoretical purposes only.

On the Right side which have the letters " B, D " I am trying to adjust the float to 22-23mm .

As you can see at point "B" ( which you can see the tab is in the bent up position) I am bending the tab up to get the correct measurement of 22-23mm, in which case it lowers the float into the carburetor at point "D" Its getting closer to the side walls of the carburetor. ( I hope the picture is clear enough to see it). My measurement as of now is 29 MM. If i go lower to say 25mm , the float will be resting on the Carburetor side wall, which can not be good. Any insight to this will help

Thanks again for the quick responses on this problem.

[Tweeker]

Just checking if anyone can tell me if the pictures look clear enough to view..thanks

[Houdini]

Tweeker,

Here is a link to an on-line manual for your bike:

http://search.ebscohost.com/

Type in Library for user ID and password.
Go to small engine repair, motorcycles, suzi, then
GS400-450 CHAIN DRIVE, 1977-1987

Assume you compared the original & replacement floats and they appear the same.

If all else fails, as a crude rule of thumb, many times when floats are adjusted correctly the float arm is level / parallel with the float bowl mate / gasket face.

If this info does not make sense to you, and you are still having carb adjustment / engine tune problems, I would say "what we have here is a failure to communicate"...might want to consider looking up a member close to you that you could take the carbs / bike to for assistance.

Don't give up, you can do it with a little GSR help.

[Tweeker]

Thanks allot Houdini, I did just that. The site is awesome for reference. On Sat. morning I will be putting these babies back in the bike and see how it runs. Appreciate the post, would be nice to meet someone local to recheck what I have done, but I think I will give it a shot and see what happens.

Thanks again Houdini !

[Suzuki mad]

I know you are working on carbs for float height here but I have a question for you. Are they the origin al carbs for the bike?

Just those float are from the late 1970's and not the later black type which I would thought your GS would have been running. (1981??) These metal type were prone to leaks and it could also be why you are having problems getting the adjustment.

Suzuki mad.

[Tweeker]

Hi Suzuki mad,

The floats are new. I ordered them through Suzuki and they sent the original floats for my 1981 GS450T. The old ones did have some pin holes in them, thats why I replaced them.

So to inform everyone that was watching this thread, I have the carbs in and working 110% !!!! The bike runs like a well tuned machine !!! I cant believe how well it runs.

Everything that I replaced on the carburetors I replace on both Carbs. The Floats, gasket for bowls, the O-rings on the air screw and choke + needle jet o-ring, I replaced air idle jets, Needle and valves with the washer and screens, and new t-Nipple for the main fuel line that connects both carbs.

I took it around the block to see how well it was going to perform and it ran like a charm. I decided to take it for a longer trip and drove it to town to fuel it up with some new 91 octane gas and reset my odometer to see how my MPG was. That went so well I decided to take it for a longer trip out in the country and put about 60+ miles on it. AWESOME RIDE !

It has sooo much power now, I cant believe it! Its instant power when I throttle it. It doesn't spit and sputter at stop signs any more and in 6th gear I have so much power.

So Thanks everyone for your input on my problem and appreciate all the advice and tips !!!!!!