1972 Triumph 65HP<br />MDL#65273S<br />SER#J017641<br />engine runs well, however when shifting into fwd or rev eng will die. advancing the throtle up will allow a hard shift and then will pick up RPM ( SPEED ) and operate normaly. what would be the starting procedure for trouble shooting the fault?<br /> Carbs are clean ,fuel is supplied in sufficent quantities, battery shows 12.8 V avaliable, primerbuld is stiff and plugs are clean with spark at all three cyls. No adjustments have been attempted ( electricaly or mechanicaly) 