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Old 13 June 2008, 17:25   #1
mdt
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Chopping transom

I am looking at sticking a short shaft motor onto a long shaft hull.....

What would be your weapon of choice for chopping the transom down to take a short shaft? I am thinking that making up a pattern and using a router ?

After one has taken the brave pills and has done the chopping would I just need to re-glass bits of transom back up to a thickness similar to the rest of transom ?

any one out there with some photos of how they have done this?
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Old 13 June 2008, 17:44   #2
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I would think long and hard about doing this. A search on here will bring up many stories of people trying to build their transom back up because of water spilling over the top and their outboard getting swamped etc.

If its just because you happen to have a short shaft kicking around you might be better to trade it in.

Cutting the transom down is easy, building it back up with strength is a monumental task!
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Old 13 June 2008, 17:50   #3
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Quote:
Originally Posted by mdt View Post
I am looking at sticking a short shaft motor onto a long shaft hull.....

What would be your weapon of choice for chopping the transom down to take a short shaft? I am thinking that making up a pattern and using a router ?

After one has taken the brave pills and has done the chopping would I just need to re-glass bits of transom back up to a thickness similar to the rest of transom ?

any one out there with some photos of how they have done this?
Is it a sib or rib boat ?
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Old 13 June 2008, 19:08   #4
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depending on weather or not yours is rib or sib you may have to go a bit deeper than anticipated ,i once lowered a transom on a long shaft humber 16 sib to fit a short shaft, it went ok straight but would airiate or cavitate on turns , the reason was the inflatable keel profile ,we had to take off another 3 inches to get around it ,cured it in the end but the engine was really low in the water and when at anchor water would slop in but sibs are wet boats anyhow in general.
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Old 14 June 2008, 06:14   #5
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If I were you, I'd definately look for a long shaft engine. Otherwise you should use a jackplate; in order to lower your engine. The problem that will arise then is that your engine is almost below the waterline when you're off the plane and with heavy waves it will dive under now and then, so probably you'll get water in you're carbs and that sort of nasty stuff.

But if you do it: DON'T SPOIL YOUR TRANSOM and USE A JACKPLATE.

Extra nice feature of a jackplate is that you can easily try out different engine heights in less time than normal, and without spoiling your transom.
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Old 14 June 2008, 07:03   #6
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Yep - definately look at a long shaft engine. You'll encounter no-end of problems by cutting the transom down, water gettting in - in a following sea, cavitation, etc.

I assume you must have found a 'mint' standard shaft engine that has swayed you to consider this rather drastic option. Bit like prying the engine out of a Porsche Cayenne so you can stick in a lawn-mower 2-stroke to improve fuel economy!!!
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