April 26, 20188 yr Hi All, Does anybody know carburettor settings for a Sherpa 198 with a L2627 Mk 2 Amal? It's current setting are Slide No1, Needle 2B1(clip is fitted in the middle) , Pilot jet 20, Main jet 150, Needle jet 106 and the pilot screw is 1 and a half turns out. The bike is really boggy at low revs and won't respond to quick throttle movements, Has anybody got any ideas where to start? Thanks Andrew
April 26, 20188 yr I don´t know about Bultaco Amal settings but a slide with no 1 opening.......That sounds incredibly rich. I think something between 2,5-3,5 would be normal. Throttle opening comes into effect just above idle and flattens out at approx 1/4 of opening where needle and needle jet is more important. I see Inmotion list thottle valves with 2,5 to 4 openings.
April 26, 20188 yr Author That was my first thought when I took it apart. The early Sherpa fitted with a Mk1 Amal had a 3.5 slide fitted going by my manual but I can't find any settings for a Mk2, probably because most people change them for something better.
April 26, 20188 yr Andy - Standard slide is #3 cutaway. Of course, any carb. tuning (on this or any other bike) should be the last step in an overall tune-up - you must first ensure that everything else is OK..........
April 27, 20188 yr Have a close look at the hole in the needle jet. It should be round, but they wear oblong. That jet and the needle that rubs on it (the slide needle) wear very quickly and cause the symptoms you are describing, hence why people are telling you to buy a proper carburettor Edited April 27, 20188 yr by feetupfun
April 27, 20188 yr The Amal will work fine if the needle, needle jet[106] and slide[3] are all in good condition, these need to be replaced regularly depending on how much the bike is used. It is basically impossible to get the bike to run correctly if the needle jet is worn as feetup said .Pilot should be a 20/25 and main 140/150. The Bings and Amals are particularly prone to wear whereas other carbies- dellortos, mikunis, keihins aren't Cheers Greg
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