Longshaft 200 HP on a short transom?

[Jungleboat]

Hi,

My boat is 23 ft long by 8 ft wide, with a shallow V hull.

Today should have been a special day, as all repair work on the fiberglass was done and the mechanic was supposed to be picking it up from the shop, taking it to our boat club and fitting my refurbished Evinrude 200 V6.

Instead I get a phone call, seems the transom is "2 inches" too high (edit - too low!)

My (vague) understanding is that such things come as 15, 20 or 25 inch, so I'm not sure how it could be 2 inches off?

I've done some searching and sniffing around but all the threads on this topic seem to be about small engines, where a bit of alloy does the trick.

What would be needed to hike this very heavy engine up a bit? Replacing the engine is not an option, as I'm on Borneo and had to have had the thing rebuilt.

So I guess my questions are:

1. What real-world difference would a 2 inch low cavitation plate actually make?

1.b. What real world difference would a 5 inch low cavitation plate actually make, presuming the mechanic measured it wrong?

2. I'm now entirely out of budget for this boat, so what is the cheapest means of fixing this issue that remains safe and sea-worthy?

I'm not interested in making anything adjustable, just need to know what would be a safe alternative to fitting a new transom or spending nearly as much on a factory "jackplate"?

Could we just bolt a stainless plate on there? How thick would it have to be? Bolted to the front or the back of the transom? Something else?

(As an aside, this boat really has lived up to the Bring Out Another Thousand adage, with the fiberglass people, the engine people, the trailer person and even the boat club people all getting in their "Ah, problem you see, need more money...?"

More money.. always more money...

I'm sick to death of coughing up more money for the same damn boat - not to mention the number of "tomorrows" that really mean "Maybe next week", the "Already done, no problem lah" which really means "Maybe next week" and the "Yes, yes, I'm doing it right now", which really means "Maybe next week".

The "maybe next week" thing has become 3 ^&%$ months now and my budget is dry, so please, I don't want to hear about your friend's hydraulic jackplate with his twin 350s, I just wanna know, can we just bolt this 200 V6 onto a metal plate or something?

Thanks!)

I'll attach a pic...

It looks messy in that pic but much of the fiberglass has been replaced/repaired and the existing transom wood appears to be solid.


JB

 

[steely51]

Re: Longshaft 200 HP on a short transom?

If I am not mistaken, that 200 is mounted to the transom by means of bolts, it seems to me where ,the transom top sits in relation to the bottom of the transom mount on the engine makes not much difference. you can put a nice piece of wood accros underneath the transome mount for a little more splash protection and if the transome is stong enough to hold the weight there should be no problem.
you might double check my answer, but I heink this is correct.

 

[Jungleboat]

Re: Longshaft 200 HP on a short transom?

Thanks Steely.

Unfortunately we can't go by the holes in the transom, as they have since been filled in and were the mounting holes for the old 150 HP engine.

I never saw that engine, just bought the boat as a restoration project. Managed to find a 200 HP engine for it but only today (after a few months and $4500 on rebuilding it) got told by the mechanic that the transom is too low.

Have continued reading other threads and other forums; seem 2 inches below the hull is going to seriously degrade both performance and fuel consumption. Still not sure what to do with it.

In the US or UK I could have bought a virtually brand new boat for less than the cost of repairing and refitting this thing but here you just have to repair what's available.

 

[Chris1956]

Re: Longshaft 200 HP on a short transom?

Normally a boat of that size would have a 20" transom (longshaft) or larger. All that aside, 2" is not a lot to make up. A lot of motors have the ability to be raised up 2" or so. I know my '98 Johnny 150HPV6 has that must adjustment on the mounting bolts. Hopefully that will work for you.

 

[steelespike]

Re: Longshaft 200 HP on a short transom?

The mount has adjustment holes to raise the motor; has the mechanic raised it all the way.
Ive seen smaller motors raised 2 or 3 " just by raising it and putting in the bolts. The top of the bracket doesn't
offer any support so doesn't need to be in contact with the top of the transom.The top bolt needs to have enough transom for support.
You could add a metal angle iron or plate across the inside of the transom to spread out the stress.Maybe a 3/8" or 1/2" metal plate across the inside of the transom might allow you to sneak the top bolts above the transom with a piece of white oak to fill the space between the bracket and the plate.

 

[j_k_bisson]

Re: Longshaft 200 HP on a short transom?

Need more information.

The boat transom is for what size of motor? 20" or 25"?

The motr is what length? 20" or 25"

An Evinrude motor can be raised or lowered by a total of 4" in height by the hole in the mounting bracket. Yes it does make a huge difference on the these motors if it is either too low or too high in the mounting. Too low will cause resistance when the motor housing it hitting fast moving water on plane. Too high and the prop will cavitate.

Ideally you will want the motor to be mounted about 1 1/2" above the very bottom of the keel to the top cavitation plate on the motor. Check out the bayliner rebuild link in my signature. I have somewhat of this same problem.

 

[Slow Ride]

Re: Longshaft 200 HP on a short transom?

I know you said you were out of money but the best and SAFEST fix it to purchase a manual jackplate. They are relatively cheap (under $200.00). I found this one in 2 minutes. http://www.ebay.com/itm/Jack-Plate-..._Accessories_Gear&hash=item43a6c58b98&vxp=mtr Everything else is a patch job in my opinion and will lead to other potential problems such as stress on the transom. Do it right the first time or be prepared to Break Out Another Thousand

 

[Jungleboat]

Re: Longshaft 200 HP on a short transom?

Hi Slow Ride.

I checked the postage to Borneo for that and other jack plates - $160+

That's not a typo, $160 for postage (in fact the example you showed is still there and $170 for postage)

A 'bodge' was attempted and I've already spotted a hairline crack in it, so will save my pennies and have the entire transom replaced, rather than any further fiddling around.



JB

 

[JB]

Re: Longshaft 200 HP on a short transom?

Ahoy, jungleboat.

Have you thought about making your own setback/jack plate? All you need is 4 pieces of 4x4 aluminum angle and a few 1/2" SS bolts.

 

[Jungleboat]

Re: Longshaft 200 HP on a short transom?

Hi JB (hey, same initials!)

I would consider that but considering everything else *except* the transom has been either replaced or repaired or at least inspected and considered good, I may as well solve the height issue and enjoy a new transom at the same time.

The current transom still seems rock solid but who can say for how long? I say this because in places it's very wet.

Drilling to fit the auxillary bracket resulted in water dribbling from 1 of the 4 holes. Tapping with a rubber mallet shows no difference in sound between this area and anywhere else. Also I noticed that there was no drain plug, nor any kind of tubing, just a hole. You could put your finger in there and feel soaking wet wood, and yet that wood is still as hard as iron, suggesting it's some form of tropical hardwood, possibly even the famous Borneo 'ironwood'.

Or it could be some cheap ply that will be rotten in a few months...

One of the things I like about this boat is that it has virtually no stringers, just shaped fiberglass to create its strength. The one big wooden bit is the transom and its causing problems and keeping me awake at night, so I think I'll just change it.




JB