sylvester Posted November 29, 2013 Report Share Posted November 29, 2013 Hi all, Frustration with my 248. Just rebuilt with new piston, rings and rewound ignition. ran ok at first, but after around 10 mins,it just cut out. Plug saturated. Now, with clean plug, it starts first or second kick, runs for a couple of secs, then stops. Plug saturated with fuel. The carb is an Amal concentric mk.2. The float is good. Float needle fine, and fuel shuts off about 3mm below top of float bowl. Am I missing something? If I put a mikuni on, what size and jetting. Any thoughts welcome. Quote Link to comment Share on other sites More sharing options...
cvgmmartin Posted November 29, 2013 Report Share Posted November 29, 2013 Perhaps your crankcase is flooded with fuel and until your clear it of fuel, the plug will keep becoming saturated with fuel. Does the carb and inlet manifold slope down so that any overflow from the carb goes into the crankcase? Quote Link to comment Share on other sites More sharing options...
zerorev3rev4 Posted November 30, 2013 Report Share Posted November 30, 2013 do a compression test if that ok use a car strobe light and see if the spark fails when engine cuts out sounds like condensor failing ie poor spark cant burn fuel and fouls plug thus stalling ,the problem is not necessarily the carb Quote Link to comment Share on other sites More sharing options...
sylvester Posted December 3, 2013 Author Report Share Posted December 3, 2013 Thanks for your thoughts. Zerorev; that was a great idea. Just tried it. The engine starts great, then dies as before after a few seconds, and the strobe stops flashing too. The condenser is brand new, so will investigate rest of ignition. I suppose the strobe will continue flashing even if the plug is wet?? Quote Link to comment Share on other sites More sharing options...
lineaway Posted December 4, 2013 Report Share Posted December 4, 2013 I would replace the condenser again and check the grounds. Quote Link to comment Share on other sites More sharing options...
zerorev3rev4 Posted December 5, 2013 Report Share Posted December 5, 2013 as above try a new condensor but do away with one on stator ( could just snip wire through flywheel hole ) and fit one under tank an old mini mg or beatle type will do and mount to frame this way it wont over heat and pack up ,get a good make one like lucas ,,, the new stator type on the shelf today arnt much good ,i take it points look ok and the wiring isnt earthing out Quote Link to comment Share on other sites More sharing options...
chappo Posted November 28, 2014 Report Share Posted November 28, 2014 Hi zerorev3rev4, Just read your old post re the 248, having identical problems with mine, it's all listed under chappo 248 coil relocation. Read up to the last post......how did it end, was it the condenser,carb or something else. Thanks, Dave. Quote Link to comment Share on other sites More sharing options...
b40rt Posted November 28, 2014 Report Share Posted November 28, 2014 Bet it was carb ! Quote Link to comment Share on other sites More sharing options...
chappo Posted November 28, 2014 Report Share Posted November 28, 2014 b40t, Hope so , just taken delivery of a new Mikuni that's going on this weekend !!!!!! Dave. 2 Quote Link to comment Share on other sites More sharing options...
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