I recently replaced my points on my r90/6 and can't seem to advance the timing enough to get the bike to fire up. While using the alligator clip to light bulb method to set the timing initially I can only turn the plate enough to turn the bulb on about 3 cm from the S marks and on the other end the bulb lights up at the F. A friend of mine suggested i skipped a tooth on the timing chain. It's almost like the range of adjustment has moved. Any Ideas? Thanks.