Eric; transfer to exhaust timing relationship?

[jaguar]

hi Eric. Can you please tell me how the two relate? Is their perfect timing dependent on being 30 degrees apart? (90 exhaust, 120 transfers). If someone wants to change the porting for more top end power then do they need to raise the transfers as well as the exhaust port? What is a good generic timing in degrees for these two if the engine is being setup for motocross? thanks!

 

[Rich Rohrich]

Eric doesn't get much chance to hit DRN during the winter busy season. Best bet for a question like this would be to pick up his book, or one of the other good two-stroke books that cover porting. The A.Graham Bell book and John Robinson books are very good.