dirtmudnroost Posted February 11, 2005 Report Share Posted February 11, 2005 I own a 76 OSSA 250 MAR with the AMAL 627 Carb and have not been able to find any information on this Carb as most of the machines imported to Canada came with the IRZ unit. I am attempting to obtain the original stock configuration Jet sizes(Pilot, Needle Jet, Main Jet) and part numbers for various items(Needle Jet Holder, Float Needle, Float Needle Seat, Carb Gasket and O-Ring Kit)), along with the settings for the Pilot Air Screw, Throttle Stop Screw and the appropriate Clip setting on the Needle. I would if possible like to find any servicing/overhaul/parts information pertaining to this Carb in print(or digital) if available. Can anyone provide any assistance or direct me to someone that can. Please forward any information to dirtmudnroost@yahoo.ca Cheers Quote Link to comment Share on other sites More sharing options...
woody Posted February 11, 2005 Report Share Posted February 11, 2005 IRZ carbs were fitted up to '73. All of the MAR models had Amal 627 fitted from about '73 onward up to your '76 model - unless the States and Canada continued with IRZ a bit longer, don't know. All of the manuals however only list the IRZ, not the Amal. First of the Amals were bolt on fitting, then in about '74 they were push on into a rubber inlet hose (different cylinder barrells for either) Standard settings for the Aaml carb are pilot 25, needle jet 106, main jet 150 (maybe 160) needle clip on the middle groove (there is only one needle size) Float height isn't adjustable. Throttle slide number 3. There isn't much you can do in the way of servicing other than replace all of the components but there is always the possibility that the carb body itself may be worn, depends on how much use it has had over the years. If the carb is the bolt on type, new ones are available as they are still made in Spain. If it is push on, these aren't available anymore, they were unique to Ossa I believe. They are only avalable as 26mm now though, 27mm no longer made. All of the parts, or a complete new bolt on carb, are available from both Surrey Cycles and Hitchcock's here in the UK. They both have web sites and both have exploded view diagrams of the carb with part numbers - at least Hitchcocks do anyway. http://www.hitchcocksmotorcycles.com http://www.surreycycles.com The bikes do run ok with the Amal if it is working properly but an alternative is the Mikuni VM carb as these are available from the States cheaper than the Amals are over here which are about Quote Link to comment Share on other sites More sharing options...
outlaw dave Posted February 11, 2005 Report Share Posted February 11, 2005 Please contact me off line at - daverhodes@shaw.ca - I am located in Vernon BC and have some parts and info on the Ossa. Quote Link to comment Share on other sites More sharing options...
charliechitlins Posted February 11, 2005 Report Share Posted February 11, 2005 Amal carbs are made out of a very poor quality zinc alloy, and to find one that didnt have a badly worn body, would be extremely unlikely! Replacement is really the only option here, unless you can put up with poor running enigine, caused by worn carb. At least one outfit in the US specializing in British bikes is sleeving worn Amals. Quote Link to comment Share on other sites More sharing options...
jaylael Posted February 12, 2005 Report Share Posted February 12, 2005 Back in '76 I rode a "350" OSSA MAR and it had the Amal carb, stock. In '78 the Bolger "BLT" bike came out here with a mikuni on it and I must say the thing ran pitiful compared to the '76. What I mean is fluffy lean bottom and midrange and overall less power on heavy accelleration also. The airbox may have been restrictive, but I found they ran, and started better with the Amal. I also ran a works Bing carb. with choke which was given to me along with a works exhaust pipe by John Taylor (of Yankee motor co.) OSSA explorer trials/trail bikes all had the slip fit Amal here and we sold loads of 'em. The OSSA dealer I worked for set a national record for the sale of OSSA motorcycles in 1974, and the biggest part of them were explorers. There have got to be tons of those bikes still out there somewhere. One bad thing was the common flooding of the engine when the bike was laid on it's side (ahem) for 15 seconds or more. Mikuni's are friendy and easy to tune, but back then I don't think I knew as much about jetting as I do now so it is a moot point. Setup was probably the reason I liked the Amal better back then. JL Quote Link to comment Share on other sites More sharing options...
dirtmudnroost Posted February 12, 2005 Author Report Share Posted February 12, 2005 Gentlemen, Just wanted to thank you all for your help with the AMAL info your assistance is greatly appreciated. Cheers Quote Link to comment Share on other sites More sharing options...
feetupfun Posted February 13, 2005 Report Share Posted February 13, 2005 "Back in '76 I rode a "350" OSSA MAR and it had the Amal carb, stock. In '78 the Bolger "BLT" bike came out here with a mikuni on it and I must say the thing ran pitiful compared to the '76. What I mean is fluffy lean bottom and midrange and overall less power on heavy accelleration also"Even the best carbs will perform poorly when they are jetted wrongly! Here in the UK a very common mod with the old Spanish bikes, was to fit a Mikuni carb...........but I would agree a waste of time if you dont know how to jet properly. If you can get hold of the standard Mikuni carby from a Kawasaki KT250, it fits straight onto the MAR that has spigot mount carby and the jetting is perfect straight from the KT. Quote Link to comment Share on other sites More sharing options...
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