in the process of replacing wood in transom as original rotten so had to take engine off and noticed crystals and moisture coming out/off around the head gasket,it has been about 3 weeks since engine last run is this normal,i am in the uk so runs in salt water.engine use to start first time and tick over was spot on but now tends to cut out when put into gear(although i have noticed the tick over to be very low now)but if i take coweling off and manualy apply throttle via carb engine runs fine.also whilst taking the loom off(i do have a service manual)i noticed two extra wires with bullit connectors(wires are blue/white and green/white yet all others are single colours)in the loom but these are the only wires not in my manual diagram (engine model 507F9B-s/n1254)