longshaft shortshaft

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skyetoyman
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longshaft shortshaft

Post by skyetoyman »

I have a crescent 42 (14ft) boat with a 20" transom. My outboard is a century longshaft 23" bracket to cavitation plate. Will it be too deep in the water.
LLS c 1961 on a crescent 42 boat c 1980 + wspcl c 1976 + 102 SD8561 c 1944 + 102 ACR 1948
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Todd
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Re: longshaft shortshaft

Post by Todd »

Probably not. The official line is, with your boat loaded normally, the waterline should be within a few inches of the bottom of the exhaust tube or clamp bolt (holding the lower unit onto the drive tube). Your choice.

The issue is the potential for difficult starting if the exhaust tube is sunk too deeply into the water. Causes too much back pressure - in fact,providing some back pressure relief is the reason those two little holes were drilled in the exhaust tube.

But in reality, I've never seen any difference in start-ability with my 'Gulls placed a good deal deeper than that. Perhaps a really clapped-out example would suffer if mounted improperly.
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billyboy
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Re: longshaft shortshaft

Post by billyboy »

the too deep starting problem was more about the 102's i believe. with a century the only worry about too deep is the reduced performance due to the unnecessary extra drag. if the water is about 0 to 2 inhes up the exhaust tube you should be fine. just make sure the shaft hangs straight down
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skyetoyman
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Re: longshaft shortshaft

Post by skyetoyman »

picture of boat and outboard on trailer is now on General Topics --- your boat & motor pictures
LLS c 1961 on a crescent 42 boat c 1980 + wspcl c 1976 + 102 SD8561 c 1944 + 102 ACR 1948
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