Amal 289 Float Height

[youngjohn]

The front Amal 289 on my Rapide is dripping from the join between the main body and the union nut which screws on to the bottom of the main body. It has been ultrasonically cleaned and has a new needle valve and fibre washers throughout and the float is good so I suspect it is the float height. It's always dripped now and again but up to now I have put up with it.

By my reckoning, there are 2 ways to adjust the float height, either twist the carb round on the manifold to raise or lower the float chamber in relation to the body, or add more fibre washers between the float chamber and the union nut to lower it.

Is this correct and is it common to have to make this adjustment? I seem to remember doing a bit of carb twisting on a Velocette KSS in an effort to stop drips.

Incidentally, is there a specific float height measurement for the 289?

 

[greg brillus]

You need an old float to carb body banjo bolt and modify it by drill and taping a hole in the bottom, then fit a tapered brass fitting which you can slide on a small diameter piece of clear tubing. If you hold this tubing vertically alongside the carb body with the fuel turned on and the bike sitting level on flat ground, the fuel level should be just at the base of the mixture adjusting screw. This seems to be the accepted method of checking these floats on all these remote type Amal floats, and will work on the 276/289 series of carbs. If all the parts are in good condition then you shouldn't have too much trouble getting the level correct. These carbs will always drip if the bike is on it's prop/side stands to some degree. My Rapide has a more modern Kawasaki Side stand which holds the bike more upright than the original prop stands, and the original 276 carbs never drip, even with both fuel taps left on.....Cheers for now......Greg.

 

[Albervin]

Is that cylinder running rich? Usually a sign of your float being too high is petrol seeping out of the pilot hole and the cylinder running rich. I have found the washers take some time to bed in and the nut needs to be nipped up a few times before a good seal is achieved. Another one of those PITA jobs.

 

[passenger0_0]

There is no real reason for 276/289 carbs to drip. Sometimes the seat is defective and needs slight lapping. I set up my float levels by removing the small blanking bolt located at the float bowl banjo and screw in a simple fitting that takes a length of clear hose so no need to drill and tap any holes. Greg has given a good summary above and I think of this topic has also been covered in previous discussion threads. As an aside, I adjust the float height placing a shim under the float needle clip. There are many benefits in getting this seemingly insignificant adjustment right. Good luck.

 

[youngjohn]

Thanks all - both cylinders are a little rich - I'll make up a 'level adapter' and check it this weekend.