strengthning transom

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smurfer69

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hi everyone ive got mayland 16.6 had 30hp mariner on just bought mercury 60-2 stroke mint condition any advice on building up transom strength and could the xtra hp and torque damage the boat any advice would be great
 
Since no one replied, I'll give it a go, though not an expert at repowering stuff.

1. Check your owners book or for any stickers in the hull saying that you can actually fit a 60hp engine. Speed, trim and weight may be a limiting factor for hull stability.

2. Check that your insurers are happy for you to fit an engine with double the horsepower.

3. Have you got sufficient fuel capacity to run that big lump for a reasonable length of time without resorting to fuel cans and lines fouling the deck?

4. As you say the transom may not be strong enough and chopping the old one out and glassing in a thicker one is serious effort.

5. Is it worth it, when a bigger hull to suit the engine is probably the most effective way to go.

6. Is the Mayland a planing hull or a displacement? If the latter, you will burn double the fuel for a couple of knots difference in speed.

Selling your existing boat complete with engine should fetch in enough cash to buy a bigger hull sans engine.
 
Cheers mate there r no figures on hull or anywhere on boat to indicate weight of boat and engine hp ,question if the transom is 20" and engine mount is 20" to cavitation plate can the engine go on transom if it is strengthened
 
smurfer69 said:
Cheers mate there r no figures on hull or anywhere on boat to indicate weight of boat and engine hp ,question if the transom is 20" and engine mount is 20" to cavitation plate can the engine go on transom if it is strengthened
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Dunno, as outboards are outside my sphere of knowledge. I thought outboards just came in short shaft and long shaft models for tenders and deeper hulls.

It must protrude below the transom enough for the prop to run in clear water unaffected by turbulence from the hull.
 
smurfer69 said:
hi everyone ive got mayland 16.6 had 30hp mariner on just bought mercury 60-2 stroke mint condition any advice on building up transom strength and could the xtra hp and torque damage the boat any advice would be great
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Welcome smurfer
Are you sure the boat is a Mayland?
There were a few manufacturers making similar types at one time
Another make called Dejon made a very similar vessel
However back to the engine upgrade
All the 16ft Maylands I have ever encountered have had no larger than 30 hp and seemed quite balanced at that.
Would be good if you could put a piccie up

If it's the 16 an a bit ft Mayland I,m thinkibg of, not sure if I would want a 60 on the transom even if it was strenghthened to suit!
 
so u think engine would b to powerful for boat i think ur right what think would happen any ideas on that n pics i put tomorrow then u def c
 
Yes, if You post some piccies, I or someone else will be able to guide you a lot better.
I,m thinking the extra weight of a 60 might not a good idea ref the 'trim' angle etc.
Plus if it's the hull I imagine, I would say about 18 kts in a calm sea would be about enough. Let's see what your piccies tell us!
 
Yep, that's helped as hlb said.
I would not recommend a 60hp on your boat.
If you intend to keep the vessel and you have found a bargain outboard as well.
I would try and do a deal for a really modern state of the art 30 hp two stroke .
Something like an Evinrude 'E Tech' or similar.
The latest technology two stroke outboards are really efficient.
 
cheers kawasaki pretty much the information i didnt want to hear but safety first cheers mate think i rather service the mariner 30 and new impellor put it back together sell it and get a better boat without engine and put 60 mercury on that.............
 
I think you are on the right track
The Mayland is ok but an 'estuary' boat if yer gets me drift.
Have a look at 'Orkneys' and the like if you want to 'go to sea'
Keep that 60 if it is a good un
They are like rockin horse manuer second hand!
 
had the boat 4 years ur right the boat came of the river ause and i use it for sea fishing all the time , the mercury is 60hp 2 stroke tilt and trim electric start 1997 when i say mint condition thats understatment after 14 months a little tinkering started and purrs, was on fletcher speedboad and roller coaster trailer also mint a little work all for £525 i sh-t u not
 
Can't tell for sure the vintage of the boat. Late 50's early 60's maybe. The transom's weren't generally built to handle the torque of modern engines. New engines are lighter for the horsepower, but you would need major strenghtening to be safe. From the picture it looks like there has been some crushing of the transom.

I have a 40hp Yamaha on my rb tender that has a rating for 30hp / max 40. The 30 and 40 are the same engine with different carboration. You might see if that can be done to your Mariner. Personally, I think a 60 would be an overkill for your boat. I would worry about the stability at WOT.
 
once had a 235hp johson on the back of 16ft fletcher..
had the boat 9yrs no prob's with insurance
went like hot snot!!
why not drop the 60 on it and see how she handle the power just take your time with it..dont give it the beans straight away just increase steadly.
re-enforce the tamson with supports and steel plates..

the little norman 20 would take a 135hp outboard!
 
and i run a winner wildcat 17foot boat with over 340hp.
boat was rated for something like 170hp still no prob's with ins.
or handling or strength of transom..
the point i'm trying to make is you will never no until you try..
just do it sensibly..
 
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ok nice nice advice all positives i just had marine engineer looking at it tonight and says basically no problems just strengthening of transom will do fine like u say take it steady build up slowly jobs done ,cant wait to get it sorted , 2 weeks back in water back on the fish ,,,, cheers guys great advice ta
 
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