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MG MGB Technical - timing

I was faced with a hard starting B so with some time on my hands I decided to find out why. I checked fuel first because once it did start, it ran fine but would be hard to start if shut off. Fuel flow was great, no problems there. I then thought spark. I don't have a timing light so I checked it statically. When I check the dwell, it was off so I decided to pull the distributor and check the points. Upon seeing that they were slightly burned, I changed them out. Anyways, when I put the distributor back in the car, static timed it. Once started it would backfire and spit out the carbs. My question is if I missed a full rotation of the crankshaft, in other words, rotor pointing to #4 instead of #1 would the car even run? Since timing was the only thing I really truly messed with, I'm assuming that this is the culprit.
Keith Yarbrough(TD 1275)

You *shouldn't* be able to put the dissy in 180 degrees out, due to the drive being offset.
Dave O'Neill 2

Nos 2 & 3 plug leads the wrong way round will give you that. It's worth taking the rocker cover off and checking your TDC.
c cummins

thanks, I wasn't sure obviously
Keith Yarbrough(TD 1275)

Firing order is 1-3-4-2 counter-clockwise at the distributor. You can remove the spark plug at #1 cylinder, set the crankshaft at TDC checked by placing a L-O-N-G screw driver in the spark plug hole and gently rotate the crankshaft to TDC. The screw driver should NOT go deep into the cylinder.( If it does, you are 180 degrees out.) Then finding #1, then going counter clockwise should be #3, then #4 and lastly #2.

work your way from that point.

cheers

Gary
79 MGB
gary hansen

If you were a full rotation out, ie timing on number 4, the engine wouldn't start. I think Mr Cummins could be right in that you have number 2 and 3 plug leads reversed.
Mike Howlett

"You *shouldn't* be able to put the dissy in 180 degrees out, due to the drive being offset."

In my experience it can seem to fit there, although it won't fully seat. If the mounting plate is flush with the block, and the distributor flange flush with the plate, then it is fully seated in the original position timing-wise, regardless of the engine of distributor having been turned in the meantime. Problems after that will be in plug lead positioning - as long as the points have been correctly fitted and adjusted.
Paul Hunt

This thread was discussed between 19/09/2015 and 20/09/2015

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