daeman
+1y
+1 for your timing being 180 out. Being a 4 stroke engine there are two top dead centres for each cylinder, tdc exhaust stroke and tdc compression stroke. If you've accidently set your timing with number 1 cylinder in tDC exhaust then whatever residual fuel there is in the cylinder is igniting just as the inlet valves are opening to begin your intake stroke, which will cause backfiring etc through the carby.
If your unsure of where your at then you can either remove your top timing belt cover or rocker cover. Your camshaft sprocket spins once for every 2 turns of your crankshaft. There is a timing mark on your cam sprocket that when lined up, should see your crankshaft timing marks lined up also. Otherwise you can check via removing your rocker cover, line up your crankshaft timing marks and feel the rocker arms for number 1 and number 4 cylinders, to be on tdc compression stroke for number 1, the rocker arms should not be compressing the valve springs for that cylinder while the arms for number 4 should be slightly compressing both inlet and exhaust valves slightly.
Either way will allow you to make sure your distributor is fitted correctly.
Also as a side note. Your dizzy and cylinder head have a couple of small timing marks that make getting your timing right pretty easy. There should be a small raised bump on the base of the distributor body shaft, right near the drive gear. There will be a small indentation on the drive gear that you should line up with the bump I just referred to. Then with those two marks aligned there is a mark beside the hole where the dizzy goes in, make sure you have the dizzy marks pointing towards the mark on the head as you slip it in back in and providing you have your engine on tdc compression stroke for number 1. Your timing should be almost perfect.