biffco Posted June 22, 2015 Report Share Posted June 22, 2015 I have an Amal carburettor with the number 627 cast into it and 429 stamped into it. Is this the standard mar carburettor? The main jet is a 140 and the needle jet is a 106. Are these somewhere near correct? My new (to me) mar has apparently come from Italy if that might make a difference Quote Link to comment Share on other sites More sharing options...
biffco Posted June 22, 2015 Author Report Share Posted June 22, 2015 It would seem my carburettor is off an ossa mar 350 http://www.milanuncios.com/motos-clasicas/amal-ossa-mar-350-627-429-151672636.htm Should I re jet it? Is this a period upgrade? Or has the previous owner fitted the wrong carb? Quote Link to comment Share on other sites More sharing options...
dave_t Posted June 23, 2015 Report Share Posted June 23, 2015 Some Ossa Mar's did use Amal Concentric 627 carbs, 627 means 600 series, 27mm bore. the 429 stamped on it relates to the original set up by Amal (Jet sizes, slides etc) I had a list some years ago but it was lost long ago. I actually have a new 627 carb body and 2.5 slide bought years ago and never used. Could do with Woody reading this, he will probably know the best set up as he has had several Ossas. Quote Link to comment Share on other sites More sharing options...
lotus54 Posted June 28, 2015 Report Share Posted June 28, 2015 I think my 74 Explorer has a 627 Amal- it is all original and very low miles, from original owner Quote Link to comment Share on other sites More sharing options...
fourex Posted July 1, 2015 Report Share Posted July 1, 2015 (edited) Here's a couple of links to Amal UK with the original jetting specs for MAR's 71/72 and 73/74. http://amalcarb.co.uk/carbspec/carburettor/spares/id/5503/ (627/416) http://amalcarb.co.uk/carbspec/carburettor/spares/id/5504/ (627/422) As others have stated, the 429 designates what jetting Spain installed and I can't find it on the Amal UK site. I would jet to 422 specs for a MAR 250 and work from there. Edited July 1, 2015 by fourex Quote Link to comment Share on other sites More sharing options...
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