engine shaft length

[killertrance]

hi,i have a cjr 14 fishing boat and just aquired a standard shaft engine for it.the length of the engine from transome bracket to middle of prop is 24 inches,the length of my transome is 23 inches,the prop is just below boat.....is this ok??????????thanx for ure help in advance,regards,jeff oh forgot to add,the cavitation plate is very very near the bottom of the transome,not half way up or anything

[marshmat]

The only measurements you need to care about here are:
Transom height, measured vertically from the hull bottom to the point where the motor bracket would hook over
Shaft length, measured vertically from the inside corner of the motor's mounting bracket to the antiventilation plate (the big one above the prop)
Standard lengths are 15", 20" and 25". The plate should be level with the bottom of the hull, give or take an inch.
Too long a shaft will cause very sluggish performance. Too short and the prop (and cooling system) will suck air when you accelerate.

[Frosty]

hey killer, Where yer going to launch that --Stanah car park? or little Bispham.

[killertrance]

both i think......lol

[fish is a fish]

I know this thread is old, but I found this site http://www.smalloutboards.com/shaft.htm to be helpful when I had the same question.

[ted655]

The cavatation plate on the motor should be flush with bottom of hull, plus or minus 1"
A long shaft CAN be run on a short transom boat IF absolutely necessary. A short shaft CANNOT be used on a high transom.
A jackplate may aid in a "perfect" installation + help get the hull on plane faster (if it's a planing hull).