I have decided to replace the AMAL 627 on my 76 MAR and go with the Mikuni VM Carb mod, what I would like assistance with is has anyone out there done this mod and what size Carb did they use and what size Jets did they select. The other question that I have is what setup was used for mounting to the Barrel and to the Airbox. Any and all assistance and recommendations will be greatly appreciated.

Cheers

Glen

best bet would be to obtain a kawasaki kt 250 carb make sure it comes with the slide etc as its hard chromed! from a previous post someones mentioned its a straight fit no need to alter the jetting at all?

best try ebay or phil at on any sunday motporcycles as he broke a few KT's a while ago or try ellastone offroad? this is the way i'd go if i needed a carb conversion for a Mar.

If you're talking about a new Mikuni VM from Allens they may have jet sizes already sorted from people who have converted previously. If they haven't ask them to jet it as per a 250 Bultaco (they have the jet sizes for these) as the Ossa and Bult use the same jet and slide sizes in the 627 Amal. Also make sure that they supply the carb with the rubber tipped float needle and housing, because if they don't I can guarantee that the carb will p*ss out fuel at every opportunity. Mine did until I fitted that needle and housing. I can't give you jet sizes as mine was for a reed valve engine which is jetted differently.

Being a 76 model yours should have the carb that pushes into a rubber inlet hose rather than bolts on. The Mikuni will fit straight into the hose, no problem. The plastic hose from the airbox to the back of the carb won't fit the Mikuni though as the Mikuni inlet is bigger than the Amal. I use a rubber inlet boot from a 98 GasGas which fits pretty well.

If you're talking about a used Mikuni another option from the KT carb, which I've no experience of, is to use the carb from an RD250 Yam but make sure it is the one from the pair with the choke lever. These are supposed to work straight off with the Yam jets.

I'm one of the people with a 250 MAR (MK II) fitted with a standard KT250 carby and it is still working very well.

A riding buddy of mine has a Mk I MAR fitted with the standard Mikuni carby from an early 1970s TM125 Suzuki MX bike and it runs well too.

Anyone changed a Montesa 200 Cota from Amal to something else? if so what and what jets etc? many thanks, Gary,