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Ossa Mar Carburettor Identification And Set Up.

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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

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. 

I think my 74 Explorer has a 627 Amal- it is all original and very low miles, from original owner

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 by fourex

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