while doing a leak down on my 150 i could hear leakage coming out of the spark plug holes #1 would leak into #3 #3 into#5 #5 into #3 1,3,5 where around 35-55% does this mean its a leaking head gasket? if so would that cause a lost of 1000 rpms cly 2,4,6 were all around 12-20% with no...