Originally Posted by wallot

another attempt to tune the engine. no luck at all. the engine does not seem to respond to any needle movement (rich, lean, HSN, LSN no mater what we did engine just bogs on straights). idle is ok. acceleration is great but top speed issues continue. The only thing I can think of is an airleak in the engine itself as I tried two carbs but it does not sound like an airleak.

//edit - got possible cause identified will let you know if fix helped