The carbs don't sit level in service on the bike and I think you measure at the forward edge of the bowel.
When I got my premmies from Burlen the float tops were level with the top edge of the bowel. I lowered
them a bit.
I could be wrong about this so Ill await correction by those who know.
That right there looks good to me.Approx 5mm fuel level on one of mine, this puts it in the middle of the fuel level range given by Burlen, the float sits fairly parallel with the bowl top and about 1-2mm proud
View attachment 9560
Post#10
you show only a muffler.
What is the exhaust system?
850 balance pipe? Carb tune is different than individual 750 style pipes. Air cleaner affect it too.
I run BP6ES in my MKIII. Same plugs for over 3 seasons. Runs like a top
wow, this is a real problem to solve
I will take one more shot, maybe maybe the choke slides are not fully retracted and are letting in enough of a richer mixture to cause the fouling?
question: it is possible the choke is left on too long after cold start?
The filter issues previously reported were NOT to do with poor air flow through the filter, but something to do with where the rubber interfaced with the carbs for mounting, or disturbing air flow into the carb itself, it will take you all of 5 minutes to run the bike without the filter unit on to see if this is the problem.
An Amal is a fairly 'blunt' instrument and quite amenable to running considerably out of adjustment without the symptoms you describe.
Hello Lineslinger
Just a thought but I wondered if the new throttle slides are too tight in the carb bodies.
This will cause rich running.
I had this problem with refurbished slides which the carb reconditioner had fitted with not enough clearance.
The references I have seen, e.g. extract from John Healy doc attached, indicate a 3.5 to 4.0 thou clearance between throttle slide and carb body.
Probably worth comparing with your old slides and measuring slide OD and body ID or gap if poss. You can get an indication of the gap using a feeler gauge (I used 0.1mm).
Andy
A good strobe shot on the ignition wouldn't hurt, either. Good way to check the advance curve.
Just my opinion here Danno but I think once the mechanical AAU is fully advanced, the only source of erratic would be from the cam chain and pinion drive in the timing chest. Beyond say 1,500-2,500 the AAU is pinned full advance.
Sophistication of a stone ax.
Jim Comstock once stated that the Commando (maybe race Commando) responded well to a little bit less ignition advance at higher rpm; this is relative to mid range advance.
Just my opinion here Danno but I think once the mechanical AAU is fully advanced, the only source of erratic would be from the cam chain and pinion drive in the timing chest. Beyond say 1,500-2,500 the AAU is pinned full advance.
Sophistication of a stone ax.
Jim Comstock once stated that the Commando (maybe race Commando) responded well to a little bit less ignition advance at higher rpm; this is relative to mid range advance.