Hello, I am working on an AMAL 928 for a single carb BSA A65. it has the removable pilot jet under the rim of the float bowl. I have read that this was changed to the fixed orifice behind the air bleed screw due to issues with the location of the removable jet.
How much of an issue is the removable jet, is it worth rebuilding this carb or should I look for one with the fixed orifice?
The position of the pilot jet in the float bowel area was suited to 2 stokes, the pilot bush was suited to 4 strokes but how much improvement you got from the change differed from engine to engine with Triumph 500's showing the biggest improvement. If you don't have any issues carb wise currently then leave as is.
+1 with Kommando. I would advise making the decision ref possible carb replacement based on the overall condition of the carb--not just the pilot jet position. If the carb is the original one--as it sounds as if it might well be--then look carefully at bore wear. fit of slide in body etc etc. You will also certainly need a new needle and needle jet. In figuring out exactly what you need to refurb the existing carb and how much it costs you could well find that you are close to the price of a new Premier carb-- which should solve all carb issues at a stroke (only one stroke!--no pun intended!). HTH
As Kommando stated, but before you go running off check the body and see if there is an other pilot jet pressed into the body. People add the second jet thinking it is missing. Several aftermarket manuals illustrate the screwed in jet and confuse people. Also the screwed in jet could have been screwed in after the original pressed in jet was enlarged too big. This can happen while poking to clean it out or intentionally.
Thank you for the responses. the carb is original to the bike, it had about 5K miles on it when it went out of service. I never heard the bike run. it now has a 71 tbolt engine in it.
the carb does not have the pressed in idle jet only the threaded one and as I understand it that's how they came in 68. the flange is straight, slide is a fairly good fit with some scratches but definitely serviceable. all parts are in pretty good shape.
I would have headed straight for a new carb but I already have all of the parts to rebuild this one, just need to know if it is going to give me idle and low speed problems with the screw in jet vs the pressed in one.
is it possible to get the pressed in jet and install it in this carb?
I have a pair of Amals sleeved by Mike Gaylord (Thanks Mike, RIP) back in the 1980's. They have the early removable pilot jet. No idle problems, no stalling, and the air mixture adjusts easily. Since you have the parts, I would want to rebuild it and try it. Check (measure) the pilot jet and other parts carefully before installing.
I would not recommend sleeving today - but I won't post why... you'll have to PM me for the story.
When I find a good body with little or no wear then I always fit either a chromed or anodised slide as that removes the cause of the rapid wear concentrics suffer from. AMAL's own attempt at chromed pot metal slides failed but Surrey Cycles version works as its chrome on brass.