E: Engine Leaking carb

[danno]

Hi
The RH carb on my C Rapide is leaking fuel.
I seem to remember when I dismantled them last, I couldn't remove the base of the float bowl.
Any help appreciated.

 

[danno]

Correction - base of the carb body.

 

[Vincent Brake]

repair the leak

 

[Magnetoman]

If it's leaking from just above the ring that's at the base of the carburetor odds are pretty good the problem is with the float chamber, not the carburetor body. In particular, if fuel leaks past the needle and seat the level in the body will rise to above where it should be (i.e. to above the top of that ring) because the float is no longer setting the level. If this is the cause the solution is to use very fine (VERY fine) abrasive compound to burnish the needle into the seat so they again form a seal.

 

[greg brillus]

The other two common issues is either the float level could be too high, and/or one of the two fuel taps could be leaking. Check the taps one at a time by disconnecting the fitting off the bottom of the tap and leave a small cup like the top off a spray can under it overnight and see by the next day if any fuel is present. If the float level is too high, try rotating the complete carb on it's stub by a small amount and see if this helps. Cheers...................Greg.

 

[chankly bore]

All above is good advice. Toothpaste or Brasso on the taper of the float needle, remove float, grab needle, pull up lightly and twiddle about central to the bowl. Another advantage of using toothpaste is that following traffic will seem to smile more brightly.

 

[danno]

Thanks for the replies. I was thinking there was an O ring or washer that I needed to replace but looks like it's fuel level.

 

[Mikethebike]

If it's leaking from just above the ring that's at the base of the carburetor odds are pretty good the problem is with the float chamber, not the carburetor body. In particular, if fuel leaks past the needle and seat the level in the body will rise to above where it should be (i.e. to above the top of that ring) because the float is no longer setting the level. If this is the cause the solution is to use very fine (VERY fine) abrasive compound to burnish the needle into the seat so they again form a seal.

My rear carb leaks fuel when using the left propstand - I've tried swivelling the float chamber to place it closer to the carb, but now have to remember to shut the fuel off as soon as I stop. Anyone else have this problem? Mike

 

[tatty500]

Mikethebike,

What we have to remember is that the front carb has a bottom entry float chamber. So, even with the fuel taps off, the fuel in the front float and fuel lines keeps the rear float full. With the bike on the left prop-stand the rear mixing chamber is below the float level and dripping will occur from the bottom of the rear carb.

The fuel needs to be turned off well before reaching home to prevent this.

Tatty

 

[Mikethebike]

Mikethebike,

What we have to remember is that the front carb has a bottom entry float chamber. So, even with the fuel taps off, the fuel in the front float and fuel lines keeps the rear float full. With the bike on the left prop-stand the rear mixing chamber is below the float level and dripping will occur from the bottom of the rear carb.

The fuel needs to be turned off well before reaching home to prevent this.

Tatty

Thanks Tatty - sounds like another Vincent 'feature'! (though the front float-chamber shouldn't contribute to the problem) Mike