I have a stock 202 in my HQ, all I've done is put a electronic distributor, 9mm eagle leads and Bosch super sparks gapped to 1.5mm as that helped it run like a dream compared to the normal .7-.9mm, I have timed it to 8 degrees and tuned the carby with a vac gauge to the highest vacuum which is 23 if I remember correctly, but it runs rich when revved high as black smoke comes out of the exhaust at say over 4-5krpm and the spark plugs are black not the tanish colour they should? As I said it is stock besides the work above, I put a new balancer so that isn't a issue. I do use the choke when starting up which richens it a lot, but I always let it run without it