Amal premier float spindle

Just fitted a set of Premiers, both set the same, ignition on and started first kick. However, after letting it run I checked the plugs and found the left plug clean as whistle and the silencer hot to the end, the right plug totally black and the silencer just starting to warm.

On stripping the carbs, I have noticed that the float spindle does not sit correctly in its recess and is thus a little proud of the surface of the float bowls and has actually left indentations in the gaskets, I can find nothing else wrong in the carbs.

Anyone else noticed this?

My thought is that if that area of the float bowl is not sealed correctly there would be the air leak either from within the carb in the direction of the spindle to the area above the float, or rearwards to the outside of the bowl at the rear, and cause it to run lean as the pilot circuit would not get a proper 'lift' of fuel from the bottom of the float bowl.

It is the carbs, this I know as I cleaned it all up and fitted the old set Amals recently overhauled by Surrey Cycles. it ran nicely for 5 mins and the plugs were the same colour when checked.

The float spindles sound normal.

the fact that one side is fouling that plug and the exhaust is quite cooler than the other side to me could mean you have an electrical problem

by that I mean the cool side plug is is not getting spark or hot enough consistent spark and so it fouls the plug, maybe that plug's electrode wire's gap is closed?

you could start by simply swapping the plug wires after cleaning or replacing the fouled plug and see it the problem switches to the other side

I would have thought that, but with the exact same set of plugs and leads, with only a clean of the plugs they run the same colour on the recently refurbished old carbs. On either set of carbs there is no spitting, popping, crackling in the exhausts.

I have an old set of Amals in the loft, I will strip these and see if the spindles are proud of the float bowl.

I will contact Burlen to see if they consider it the norm, as their website suggests otherwise on the strip and rebuild pages.

Ive had problems with these new premiers, mine being the idle jets constantly blocking. Some days it runs fine then another day it will pop and bang until I remove the idle jets and blow the passages out then all's ok.
The fuel system is clean and there is no sign of any foreign bodies in the filters.
When I fit the old worn out amals back on there is no problem.
Ive made myself a small right angled screwdriver so I can remove the idle jets without removing a carb.
The ignition and plugs are ok.
I sometimes think I should have bought wassels or mukini`s as amals just don't seem to be of the same quality nowadays.

Confirms my suspicions, sadly they won't get off lightly - I live 35 miles away from them and they're going to get a visit. I shall let you know how I get on.

If you just fit an old float bowl assembly on to the "faulty Premier" and it runs properly then you will have no doubts.
sam

blacklav said:

Ive had problems with these new premiers, mine being the idle jets constantly blocking. Some days it runs fine then another day it will pop and bang until I remove the idle jets and blow the passages out then all's ok.
The fuel system is clean and there is no sign of any foreign bodies in the filters.
When I fit the old worn out amals back on there is no problem.
I sometimes think I should have bought wassels or mukini`s as amals just don't seem to be of the same quality nowadays.

Click to expand...

If the idle jets are blocking there has to be dirt in the system that is not being filtered out.


Glen

I had problems with the new "stay up" floats. When I set them as per AMAL recommendations they appeared OK....but the fuel level was 8mm higher than with the old floats, so they leaked fuel into the engine when the motor was off. Worth checking that the fuel level is the same in both carbs