GS450 float level help!

[Guest]

1982 GS450LZ

Carb floats are round brass type (no "step" on them, great shape/no leaks). Clymer manual (and Basscliff's website carb specs) shows float height for this bike should be 22.4mm +/- 1 mm.

Clymer manual states: "The correct float level for all models [referring to GS400s] is 25.6-27.6 mm (1.01-1.14 in.). The correct float level for GS450 models is 21.4-23.4 mm (0.84-0.92 in.)."

Problem is that when I adjust floats to about 22mm (to "raise" them), they are "bottomed out" on the top of the float chamber. This doesn't seem right. I've got them set at 22.5 mm (was trying to raise them to address lean condition, to no apparent effect), and they will bottom out (or "top out") without fully compressing the needle spring (they do shut off fuel flow).

I'm wondering if I have older carbs / carbs off of a 400, or if the floats were replaced? Anyone know what the floats on 1982 450LZ should look like, or have any insight?

Bonus frustration: Why, with no intake leaks and the floats set as high as they go in the bowl, am I still running so lean???

[JTGS850GL]

Go here:

https://www.ebay.com/itm/1982-Suzuki-GS450T-Twin-S652-1-carburetors-carbs/352875455949?hash=item52290425cd:g:S0YAAOSwmtRd1rIE

This is what they should look like. Never seen stock 1982 floats that were brass.

[mrules]

Thanks for that link. My carbs are subtly different (have larger drain screws & different choke mechanism). Floats look exactly like these aftermarket floats (from ebay), which looks like the floats in the parts fiche for an 82 450L. Not sure how I would figure out the float height specs on them if they are not the same size as OEM: s-l500.jpg

I can't imagine they are a whole lot different.

[Steve]

Some time during the '82 model year, they changed the carbs. The earlier ones were, indeed, round and brass. The later ones (like the ones shown in the link) were black plastic and considerably "less than round".

In your case, you should be SURE to use a clear tube against the side of the carb to check the actual level of the fuel. Specs call for 6.5mm ± 0.5mm.

.

[LAB3]

The floats on my early production run 1982 450txz where brass if that helps any.

[Nessism]

A fuel level check is the best way to go. It doesn't matter what the float height is if the fuel level is wrong.

And when the float needle springs get old they can't hold up the weight of the float, and when that happens the fuel level is likely to rise relative to when the springs were stronger.

If you decide to change the float seats w/needle you can typically find the real deal Mikuni parts on Amazon. I haven't looked up the part number for the 450 seats but I know you can find the larger bike parts there for good prices.

[pete]

Just to be clear, the official 1980 - 1982 model year (which means up to probably June 1982 is my guess) carbs do indeed have the brass floats, and every single carb spec I have seen posted on here, in the Clymer/Haynes, and on BassCliff's site have been for the later 83 model year and onwards. My 450 has a manufacturing date of 10/81 and it is the latest version of the 450 model line up, which is confirmed by a different colour in the wiring harness (orange instead of red somewhere from memory), 15 bolt valve cover pattern, two piece clutch pushrod setup, and the clutch pushrod seal that can be replaced without splitting the cases and is held in by the retainer.

It sounds to me like you have the correct carbs for the bike model, and I will endeavor to remember to read my genuine manual and get the float heights for you, although I'll second Ed's comment above that fuel level is the best check indeed.

With respect to your lean question, firstly we'll need to know what your intake and exhaust situation is. All stock? Air filter cleaned and oiled?

[pete]

Wow I remembered! Here's a photo of the relevant page from the factory manual. As you can see the previously mentioned fuel height is the right one, but the float height is quite different:

IMG_4203 by starpoint73, on Flickr

[mrules]

thanks for that Pete! I'm going to set the floats per that manual and check the fuel level as you, Steve, and Ed suggest.

Intake, exhaust, etc. all stock. Air filter clean, oiled, and seated well. All new rubber from the airbox to the intake o-rings Had a small exhaust leak at the crossover pipe, was causing popping on decel. Still has slight leak, but popping is better after new exhaust gaskets & reinstalling. In hunting for the leak, i think i did something that caused it to start running lean (such as adjusting the float levels). Not sure what to do next

[pete]

Too easy, hope it helps!

Hopefully once you get them all adjusted you can have a better idea on solving the lean condition as well.

[derwood]

upsidedown?

[mrules]

I did try flipping them over when I was measuring and they are definitely not upside down; float bowl only goes on if they are in correct orientation (the lever arm is too off center).