Ok, at the lake last time out and shifting went out. At this time, there was a rather large puff of smoke come out of the exhaust as the engine revved up due to the loss of shifting. We have replaced the transom, getting ready to put all back together. One of the exhaust flappers is melted, have already bought a new one and replaced. I know this is typically due to overheating, but the boat never has been above 160. My question is, can that flapper melt by any other cause besides overheating? Could it melted quickly due to the high rpms experienced when the shifter went out? And is this likely what the black smoke was from? Coupler, impeller, drive and ujoints all are good. Also, any advice is more than welcome at this point.
