March 4, 20179 yr Building a Francis Barnett with a 32A motor and seem to have starting issues from cold. Motor has been totally rebuilt, new piston, crank, mains, seals etc and is fitted with a new Electrex world ignition and new Amal concentric carb from Villiers services. Running a Villiers service front pipe and Alan Wright WES silencer. From cold it doesnt seem to be getting enough fuel, but when you check the plug its fouled. Once hot, it runs and starts fine. Can anyone confirm the best plug to use with this set up and also what pilot jet should be in the Amal. Cheers
March 4, 20179 yr Hi, I've found this on a Fanny-Barnett forum which might be of some help, with a 32A engine used the following settings which gave easy starting and trouble free running, including a reliable tick over. Amal Concentric Carburettor setting for Villiers 250 Trials Engine Bore - 1 1/16", Pilot - 20, Cutaway - 3.5, Main Jet - 400, Needle Jet - 0.106, Needle Position - 3.
March 4, 20179 yr i always seemed to be filing my slides cutaway.. 3 - 3.5 was best get the stay up float as well
March 4, 20179 yr 8 hours ago, brownie001 said: Hi, I've found this on a Fanny-Barnett forum which might be of some help, with a 32A engine used the following settings which gave easy starting and trouble free running, including a reliable tick over. Amal Concentric Carburettor setting for Villiers 250 Trials Engine Bore - 1 1/16", Pilot - 20, Cutaway - 3.5, Main Jet - 400, Needle Jet - 0.106, Needle Position - 3. Close to what i am running but Main Jet 400 ???????? I'm running a 120 If they are running a 400 it must be on Methanol or something. My settings are 26mm carb, 20 pilot, No 3 slide, 120 main jet, Needle 106, position 2 if its of any help. Re the plug i normally run an NGK BP5ES Oooops forgot to say i'm running an Amal Premier carb. Edited March 4, 20179 yr by old trials fanatic more info
March 4, 20179 yr I have had same running problems caused by stale fuel. float level should be 4.33 to 6.35mm below top of float chamber. check if the carb has a pilot bush fitted. these are equal to a 25 pilot jet. a smaller pilot jet will work as it should, but going larger than 25 will not. the bush is visible behind the pilot adjusting screw. if you need to go larger drill through with 2mm drill.
March 9, 20179 yr Check the carb is a 2 stroke one not a 4 stroke i got one brand new and it was sent wrong. Happen to a couple of people
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