Suzuki 2 Strokes

I bought these from Ebay knowing I should buy some Mikuni ones.http://www.ebay.com/itm/NEW-CARBURETOR- ... 23&vxp=mtr" onclick="window.open(this.href);return false;
Asked that seller who they were manufactured by and he stated K&L. Well, since finishing restoration I have had ongoing flooding problems. I removed the carbs at least 7 or 8 times adjusting the float levels a mm or two at a time. Same measurements with or without the gasket, etc. And nothing will stop them from flooding. Unless, I set them so low that a cylinder or 2 will not fire. I also reused my gaskets which seemed to been replaced very shortly before I bought my bike. They appear to be in very good condition, made of a harder gasket material. No matter how tight I adjust the screws which are allans. The bowls leak past the gaskets when the carbs flood. Can someone suggest a gasket material that is gas resistant as I would like to make my own or some other suggestions ? I'll be damned if I'm paying 30-40 dollars for 3 little gaskets. I also priced needle valves directly through Suzuki which I assume are still Mikuni and I remember why I chose not to buy them in the first place. $42.00 a freaking piece. Maybe, my original needle valve seats are worn ? Is there an attachment for these type of bowls to confirm float level on these bowls once they are filled ? I recently bought an RZ 350 and in it's manual it shows an attachment on the bowl that you can hook a clear tube of some sort. You bend that tube up around the side of the bowl once it's filled. Confirming the fuel height from the exterior of the bowl looking at the tube. I never seen anything like that. Pretty handy attachment on the RZ 350 bowl. The Kawaski's have one also. http://www.ebay.com/itm/Carb-Float-Leve ... 48&vxp=mtr" onclick="window.open(this.href);return false;

Gaskets are available at mike's XS http://www.mikesxs.net/product/20-7029.html" onclick="window.open(this.href);return false; for 4 1/2 bucks a pop.

I'm not sure if http://www.mikesxs.net/product/48-1429.html" onclick="window.open(this.href);return false; is the correct needle valve and seat though. Worth buying one plus teh gaskets and check it out.

I would also recommend running the float bowls across a flat sheet of wet and dry to get the faces flat. The tighter they are screwed down the more they tend to bow and leak. The bodies may also have distorted so that worth checking too.

Thanks, for the advice Richard. I can handle paying that amount for the gaskets. The flat upper tops of the bowls I did clean them well with a rubber rotary bit on slow speed to clean the old gasket surface off. Perhaps they are not completely flat across now as a result. I may try a very generous amount of Ultra Gray Gasket Sealant. I did torque down the allans pretty tight. So that might be an issue also. I took the bike out for it's first test ride today and it runs great, it will run better once I get the flooding under control. I assume it may help a little to bump the pilots up a size also. I'm running 117.5 mains and at 3/4 to full throttle it runs very well. A lot of hesitation at small throttle imputs with stock pilots. But, I'm sure the bowls flooding is part of that too.

I may be wrong as I've not tested this thought, but doesn't the float valve / float height ensure that at spec, the fuel level is slightly below the gasket surface? and that the gasket is there to prevent leaks when the bike is on its side stand, acceleration and braking and also to prevent air leaks?
If so, then leaking when sitting upright must mean fuel level is too high.
Just a thought, which may be incorrect in which case scratch this!
Cheers,
Mike

I believe you're correct yeadon. I don't think the gaskets are designed to be a liquid tight sealant. Like you said, I believe the fuel height would be very close to 27.5 mm below the gaskets with carbs installed. That is a lot of clearance even if a measurement of a float height is off by a mm or 2 for it to be gushing out like it is. That is the exact reason I strongly feel the new K&L needle valves are not working like they should. Because the fuel is leaking out the carbs in a pretty large amount. When its idling and soon as I come to a stop. I agree exactly with what you stated. I think the bowls are actually designed to leak a fair amount if the fuel level gets that high to make someone aware of the over abundant amount of fuel. I could be wrong about that though. I'm thinking as long as the floats are within a few mm of spec. There is no way the fuel should be consistently pouring out at idle, unless the needle valves are junk in their relationship with the old seats. Someone feel free to agree or disagree with that theory. Or add to it. Cause up to this point I tried nearly everthing but replace the needle valves once again. The good thing is, I have all 3 cylinders firing now. As opposed to only 2 before I replaced one bowl. Sometimes the arms on a float can become tweaked. Giving a different measurement depending on which lobe you take the measurement. But, I checked height on all 6 lobes dozens of times to assure that.

needle valves + info so you can figure out which ones you need:
http://jetsrus.com/needle_valve_float_b ... ikuni.html
http://www.motorcyclecarbs.com/Mikuni_F ... at_W85.cfm

Once you know which ones you need, you can get the correct genuine Mikuni needle valve assemblies much cheaper than from Suzuki. Also check Amazon & eBay when you know which needle valve assembly to get.

Also, what shape are the floats in?
Some people use compressed air on carbs, which can collapse the floats. Doesn't take much & you'll never get the fuel level correct.

The gaskets should seal with no gas leaking out. Carbs are often mounted at quite extreme angles and the bowl must remain fuel tight. So the leak is a problem that needs to be addressed. If not, it will leak every time you stop or accelerate and that's a hazard.

Mike Y is are correct that the float level should ensure that the fuel level stays 2-3mm below the gasket surface. The question now is whether the high fuel level is caused by the needle valve leaking or the floats being set too low ie too high with the carb the right way up.

When you set the float height, were the carbs upside down on the bench or at an angle? It's a bit of a PIA to set the height because the cabs have to be gently tilted until the float tang just touches the spring loaded pin in the needle valve. If they are all the way upside down, that pin is compressed and the float levels are wrong.

The easy way to test for leaky valves is to remove the carbs and suspend them over a large enough baking tray or similar container. Connect up a remote fuel supply and remove the float bowls. Turn on the fuel and lift a float with a finger to see if it stops the flow of fuel. You could also do that dry with a very low psi air supply ( your lungs) and blow down a clean new fuel pipe.

Some people try to polish a gasket surface witch is a definite no no. Gasket surfaces must have some 'teeth' to bite into the gasket. If you polish the gasket surface, they will leak forever more.
From your description I assume you have done this. I suggest you tape down some 220 grit on a FLAT surface. 180 grit will work even better. Drag the bowls across the paper until the surface till you get a uniform surface from the paper.

tz375 wrote:The gaskets should seal with no gas leaking out. Carbs are often mounted at quite extreme angles and the bowl must remain fuel tight. So the leak is a problem that needs to be addressed. If not, it will leak every time you stop or accelerate and that's a hazard.

Mike Y is are correct that the float level should ensure that the fuel level stays 2-3mm below the gasket surface. The question now is whether the high fuel level is caused by the needle valve leaking or the floats being set too low ie too high with the carb the right way up.

When you set the float height, were the carbs upside down on the bench or at an angle? It's a bit of a PIA to set the height because the cabs have to be gently tilted until the float tang just touches the spring loaded pin in the needle valve. If they are all the way upside down, that pin is compressed and the float levels are wrong.

The easy way to test for leaky valves is to remove the carbs and suspend them over a large enough baking tray or similar container. Connect up a remote fuel supply and remove the float bowls. Turn on the fuel and lift a float with a finger to see if it stops the flow of fuel. You could also do that dry with a very low psi air supply ( your lungs) and blow down a clean new fuel pipe.

I tried both methods of setting them. Directly upside down and partially tilted. My floats aren't the greatest, but they aren't horrible either. I had to solder all 3 of them due to microscopic cracks. But, they are air tight now. One has a squirt of gas still in it. I seriously doubt that is causing a problem. But, I could be wrong. The carbs didn't leak before I soldered the floats. I was going to replace all 3 down the line as I spent so much money on the bike. It was a must do, later thing in my mind. Which brings me to another question. The Mikexs link you posted, Richard. Has 2 separate float listings for the BS carbs. One is sold out for $30.00 and the one directly above it sells for $13.50 They look exactly the same and both refer to the same part numbers. I think the one available will work for my carbs. Correct ? The rims on my bowls are pretty smooth. But, I wouldn't say they are polished.

The expensive one mentions that it is made in Japan, so maybe the other is not. The cheap one appears to be in stock and the expensive one is not so try one and see.

The extra weight of the solder and fuel inside is probably enough for those floats to float lower and therefore not close. They must be set on an angle to work.

Time for a couple of floats.

I seriously doubt this is my problem. But, I nearly tried everything else to this point so I'm buying them right now. I would have liked to call them and see if they know what the deal is with the cheaper floats. What kind of company has no customer service number you can call ? It chaps my ass that quite a few companies deal through emails.

tz375 wrote:The expensive one mentions that it is made in Japan, so maybe the other is not. The cheap one appears to be in stock and the expensive one is not so try one and see.

The extra weight of the solder and fuel inside is probably enough for those floats to float lower and therefore not close. They must be set on an angle to work.

Time for a couple of floats.

I cross referenced that cheaper float number and the only model that appears for that cheaper float is a Yamaha XS. So, I'm S.O.L. on that one. I looked around on a few sites I'm familiar with and I think I'm stuck paying 26 bucks a pop. Unless, someone can lead me in another direction.

GT550 floats from a Suzuki dealer that discounts are $14 each + shipping.
http://www.powersportspro.com/pages/Oem ... 6021160009

Edit... oops
Just noticed you mentioned BS carbs.
GT750 floats are $27 each
http://www.powersportspro.com/pages/Oem ... 6021180008

What's the difference between 550 and 750 floats. Anyone have both to compare? Oh Shoot. I do. Let me see what they look like.

I'd be interested to hear your results. Depending on your finding, I could perhaps temporarily remove those floats from my 550 and see if that remedies my problem.