350 GTR Carburetor Issues......... Again!

[Steve S.]

Fired up the GTR today after replacing the needle and seats with new ones.  Gas started pouring out the bottom of the cases, just like before.  I am at a loss.  I have checked and re-checked all my specs, and everything seems to be right on.
My question is:  How is everyone else setting the Float Level?  In the Bridgestone Service Letter (BSG-0003) it says: "remove gasket and hold carburetor upside down (float valve closed) measure distance between gasket seat and top of float.  Correct distance should be 15/16"

Is this correct, should the float valve be closed when taking this measurement, or should measurement be done without compressing the float valve?
Thanks.

Steve S.

[slawsonb]

I have always set floats per the procedure you described (per the manual) with the weight of the float compressing the spring and never had an issue with shutting off the fuel flow. Sounds to me like the float may be binding somehow. The other thing to check is the holes for the float pins. If they are very oblong that could affect the float measurement or cause binding.
...bert

[Steve S.]

Thanks Bert.  Just found the link to this method of setting the float height.  It was in a Service Letter dated 8-1-69
http://bridgestonemotorcyclerestoration.com/service-letters/BSG-0003.pdf

Steve S.

[Colin]

steve i have a spare set of carbs, pm me your address before I get home on the 13th June and you can have them for the price of the postage
colin

[slawsonb]

The service letter points out one thing I forgot to mention. Since 350s have dual floats, it is important to make sure both sides of the float measure the same (15/16"). Sometimes requires tweaking the float to get both sides to align correctly.
...bert

[coxy]

I bought a nos set of carbs a while back and had a similar thing .it turned out the actual float tang was a different size causing it to bind to the needle(some sort of factory balls up) it took us ages to find this out end result replaced floats with originals 

[Steve S.]

Thanks for all the replies guys.  I will try some of your suggestions and let you know how I make out.

Steve S.

[farmerdl]

I have also found a difference between early and later needle seats and valves and the needles will not interchange one to the other.  Nearly the exact same issues.  Bike even ran fairly well if you stayed on the throttle, but as soon as you stopped it would loose a small but steady stream.

[old smokey]

And I'll spin my broken record - check the brass floats to make sure there are no leaks. I have had to patch two of the 4 floats on my GTR. Once they get a hole and get gas inside, they won't float to the top and make the needle valve seat to stop the flow of gas. First one I put some solder on it, second one I smeared a little JB Weld on it. Ran great until I hit the deer.

[Steve S.]

Yes,
Smokey.  The floats were the very first thing I checked.  I could not find a leak in either one of them.
I do have the bike running without flooding at this point.  I'm not entirely sure exactly what I did.  I did straighten the tabs on the floats.  They seemed to have a strange curved shape to them.  Not sure if that was the problem or not. 
 

[slawsonb]

Glad to hear the 40 days and 40 nights are over...;-)
...bert

[Colin]

Well done, it doesn't really matter if you know how you fixed 

[Steve S.]

Just went to fire up the GTR and wouldn't you know it, fuel started pouring out the right side carburetor.  I am really at a loss as to what is going on with these carbs. 

And just so everyone knows, you cannot find a new set of carbs anywhere.  Richard is sold out and so is the secondary Ebay market.

[Mike Anderson]

Contact Steve Reed at Carb Worx he is on the site. He can make your carbs better than new.
Later Mike

[ziggy stardust]

I had the same problems with my first GTR, carbs leaking and one cylinder running stronger than the other, new carbs solved the problem. I emailed RC a couple of weeks ago regarding the spares situation on NOS carbs but got no reply.
z

[rwgibbon]

Steve,

It sounds like the float is sticking or it has a hole in it.

Check the floats before you replace the carbs.

Randy

[Steve S.]

Hi Randy,
Yes, floats were checked and re-checked 6 times over.  I could not find any leaks or deformation to them.  I even submerged them in a cup of gas and looked for bubbles.  Then I shook them.  I didn't here anything or see bubbles.
Thanks.

[old smokey]

a leaking float won't necessarily makes bubbles when submerged - mine never did but you could hear and feel the gas inside when shaken. Sounds like you've eliminated that possibility.
Could you try the old needle set?
I have no new suggestions.

[Steve S.]

a leaking float won't necessarily makes bubbles when submerged - mine never did but you could hear and feel the gas inside when shaken. Sounds like you've eliminated that possibility.
Could you try the old needle set?
I have no new suggestions.

The old needle set did the same thing, that was the reason for changing them out.  I hear what your saying about the floats, but they sound bone dry when I shake them. 
I'm still at a lost.  Wish I could get my hands on a set of NOS carbs.  I waited entirely too long!

[OldSwartout]

Check the float levels and lower them if they're not already lower than spec.  Mine would dribble gas when parked on the sidestand. I bought new float valve sets from Richard and the problem remained. I finally dropped the level about a mm and the problem went away.  I went through the same process as you, checking and double checking the floats for leaks, etc.