I've just experienced the timing issue. Mine was running rich, plenty of revs when stationary, but no 'go' when driving. On checking the static timing position of both the cam and crank, I found that they were out by a few teeth. I set the position of the cam timing mark against the head, then relieved the tension of the tensioner so the cambelt went slack. Then, I could move the crank the shortest way around until it's mark lined up on the engine block timing mark. Next I put the belt back on and took up the slack again with the tensioner. having done all this, I turned the engine round by hand a few times to check that it was fine. The improvement in running was instant, power where I wanted it.
Thanks to the previous posts and links which helped no end!