Carburetor Problems - Mikunki SBN

[seapoo]

I'm installing a new SBT engine in my 1997 GSX, so I decided to rebuild my carbs too.

When checking the pop-off pressure I noticed that I have a leak between the carb and the fuel pump. (of course all of the seals are new cause i just rebuilt it) Does anyone have any idea how to fix a leak like this? Both surfaces are free of debris and corrosion; both surfaces look perfect. There is one flimsy diaphragm and a conic filter between the pump and the carb.

I'm tempted to try and seal the parts together with high tack gasket sealer....
Any better ideas?

[Technical Support]

Re: Carburetor Problems - Mikunki SBN

DO NOT apply sealer! If you can't get the surface mahcined, you'll need a new carb body.

[seapoo]

Re: Carburetor Problems - Mikunki SBN

ok, no sealant. Any idea how far I should hve the machinist take it down? .001" or more?

[Bill O'Neal2]

Re: Carburetor Problems - Mikunki SBN

There should not be an air leak unless you have either a gasket in wrong or pinched or some other fixable problem. You can use a flatplate with sand paper on it to rub the cover across to see if it is warped.
You can put a rubber gasket ( supplied in each kit) in there over that oring area. It is the same gasket you put under the fuel pump diaphram. It is called a diaphram dampner.

[Bill O'Neal2]

Re: Carburetor Problems - Mikunki SBN

Do not machine it.

[seapoo]

Re: Carburetor Problems - Mikunki SBN

I don't think it is the cover. I used the cover from another carb set and still had the same problem. I have also tried a variety of other gaskets included in the kit and the leak got worse.

[Bill O'Neal2]

Re: Carburetor Problems - Mikunki SBN

Did you try the black rubber square diaphram dampner gasket ?

[Technical Support]

Re: Carburetor Problems - Mikunki SBN

I have no idea - until it's flat.

[seapoo]

Re: Carburetor Problems - Mikunki SBN

Yeah, I tried it by itself. I tried it with the flimsy diaphragm. and I tried with two flimsy diaphragms. No luck.

[Bill O'Neal2]

Re: Carburetor Problems - Mikunki SBN

If all esle fails, use a very tiny amount of GASKETCINCH along that edge of the carb. Just enough to seal the leak. It is only susposed to hold 4 psi.

[seapoo]

Re: Carburetor Problems - Mikunki SBN

4PSI, im confused by that. I was testing the pop-off pressure and had 12 on the guage when it started to leak. If I pump quickly it will go all of the way up to 32PSI and pop. The other carb pops at 34PSI.

[Technical Support]

Re: Carburetor Problems - Mikunki SBN

WTF are you talking about? The surface pointed out in your pic has nothing to do with pop-off, Bill is talking about fuel pressure in the housing.

How exactly are you testing?

[seapoo]

Re: Carburetor Problems - Mikunki SBN

hehe I'm a newb. I placed one end of each tube onto each of the fixures labeled in red to equalize the pressure. I then applied a guage and pump onto the fixure labeled in blue. I used wd-40 to lube seat assembly. Covered the seat assebly to sheild from spray and started pumping.

[seapoo]

Re: Carburetor Problems - Mikunki SBN

...perhaps this method is the problem?

[Technical Support]

Re: Carburetor Problems - Mikunki SBN

Read the tech article on it and watch our videos.