Float Levels For Concentric Carbs

OK. Have completed a few maintenance tasks on my T100R: Replaced knackered throttle and speedo cables, spotted and replaced almost broken wire between the coils, replaced split rubber boot on clutch cable/gearbox cover, adjusted tappets (all of which had no movement at all (previous owner, not me!), and inspected float levels.

The floats I happily discovered to be the newer stay-ups, with new alluminium float needles, and new needle jets to boot (why don't people keep evidence of work done!) HOWEVER, the floats were higher than recommended so I lowered them to what they should be. Result, wouldn't start at all. So I re-set the float levels to where they were and she now starts. Either my measuring was rubbish or something else is at play, or maybe the stay up floats do need to be higher than the originals (although Amal dont say so. Any thoughts anyone?

 

Hmm. Good point. I think both Bonnies and Commandos were also often "upgraded" with Mikuni carbs.

I guess that 50 year old Amals are not exactly "cutting edge".

 

1972. Unfortunately the carbs don't have the drain plugs at the bottom to facilitate a levelling tube (manometer) to be more accurate with the petrol/float levels, I have to take the bowls off and try and get the levels right that way.

 

OK. Been fiddling with the carbs over the last few weeks (well, when the weather permitted). Problem was stuttering and "holding back" when accelerating. Initially I purchased a Colortune as I was going crazy trying to get the mixture right at tick over All done in 5 minutes and ticked over fine. However this didn't help at wider throttle opening of course. In the end I moved the carb needle from 1st to middle position just to see what would happen. Miraculously she now accelerates brilliantly with no hesitation or holding back. Obviously running lean at higher throttle openings. Sods law I have now done my ankle in so can't ride at the minute but in a couple of weeks or so..... Happy days.