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MG MGB Technical - 73 'B' won't start

Just replaced both floats and jets(and seats) on my twin HIF's to correct flooding issues. I know I got the floats adjusted right(approx. 1.5 mm) but now it won't start. I tried w/o choke pulled, with choke pulled, with gas pedal pushed in to start...and no luck. Set mixture screws halfway in...no luck....HELP!!. Car starts and drives before flooding issues came about. Thanks.
J P Wyc

It is possible that you have flooded the plugs. Remove them and let the gas evaporate off and out of the cylinders. If you know what you are doing you can use a propane burner to assist with the plugs. You will know if you have flooded it by a very strong smell of gasoline and the plugs will be blacked and/or wet.

Once dry, clean the plugs up with a wire brush and replace in the block.

Paul
Paul Barrow

Are the float chambers filling with fuel OK?
Stan Best

What about the obvious - getting spark? Getting fuel to the carbs? I've had a float get stuck after working on carbs and wouldn't allow gas in the bowl.
Mike D.

Another less obvious thing is the rotor arm. These can develop minute cracks ... so the spark (or a lot of its energy) goes down the distributor into the sump (harmlessly) instead of to the plug. Swap the rotor arm out for one that is either new or you know to be good. I always carry a new one in the glove box to be safe!

Paul
Paul Barrow

By the way folks, thank's for the comments I got my 'B' back started and running and completely synchronized. Since I replaced both floats (one is bad...fuel inside)to start with I did changed the mixture screw settings during disassembly. Happened to talk to a guy who worked on SU's and advised me to screw in mixture screws all the way in and back out a couple of full turns to get me in the ballpark for a start up.....sounds simple and does work....Joe
J P Wyc

Not all the way in, but only as far as is needed to get the top of the jets up to the top of the bridge. Then wind them back down two full turns, and that is the starting position. As described in all the manuals. All the way up then two full turns down will be weaker, possibly too weak.
Paul Hunt

This thread was discussed between 03/08/2008 and 08/08/2008

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