motoswm Posted March 4, 2017 Report Share Posted March 4, 2017 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 Quote Link to comment Share on other sites More sharing options...
brownie001 Posted March 4, 2017 Report Share Posted March 4, 2017 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. Quote Link to comment Share on other sites More sharing options...
totalshell Posted March 4, 2017 Report Share Posted March 4, 2017 i always seemed to be filing my slides cutaway.. 3 - 3.5 was best get the stay up float as well Quote Link to comment Share on other sites More sharing options...
old trials fanatic Posted March 4, 2017 Report Share Posted March 4, 2017 (edited) 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, 2017 by old trials fanatic more info 1 Quote Link to comment Share on other sites More sharing options...
stan wellback Posted March 4, 2017 Report Share Posted March 4, 2017 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. Quote Link to comment Share on other sites More sharing options...
greevesrob Posted March 9, 2017 Report Share Posted March 9, 2017 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 Quote Link to comment Share on other sites More sharing options...
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