Engine Mounting...tips please!

[slimtim]

Will soon be mounting my engine on my RIB. Just wanted to make sure there aren't any issues I may encounter along the way. We have made a template to get the exact hole positions and fabricated a marine ply plate to put between the transom and engine saddle. I have choosen to keep the engine in the middle rather than offsetting it and will have it at the recommended height when on its upper mounting holes (so I can move it up if I want to in the future).

I was thinking of gluing some left over hypalon from my tube fitting over the top of the transom to give it a little padding...good idea or not? I don't see what I would have to loose.

Any tips etc on fitting engines would be appreciated.

Cheers

Tim

[Pete7]

Tim, don't understand what the marine ply is going to do for you. Also what happens if you need to lower the engine one hole because it cavitates to much in the corners ?

Otherwise okay, spare hyperlon piece should be okay, have a chat with MeMe about colour coordinating accessories and cushions

Pete

[Mark Halliday]

Tim

I would put the big bit at the top and the little spinny bit at the bottom.

Didn't they teach you anything at S'ampton Uni?

As Pete says, wots the ply for? Or is that just the template for drilling the holes.

[Jono Garton]

Tim

I have rigged 2 Shaky 520's, the engine wants to be slap bang in the middle (no offset) and very low as the hull was designed to be a longer boat, you may need fins on the engine to stop cavitation with a light engine, the 520 seems to be very stern light, and handeled better with the four stroke.

Drop me a line if you need any advice.

[slimtim]

Thanks for the advice.

We made the plywood pad as the tohatsu manual told us to...I wasn't convinced we needed it but I guess it will protect my shiney gelcoat on the transom! It will also be used as a template.

The standard height to mount the engine is with the cavitation plate 10-15mm below the bottom of the boat. This should be enough shouldn't it?

Tim

[Jono Garton]

Originally Posted by slimtim

The standard height to mount the engine is with the cavitation plate 10-15mm below the bottom of the boat. This should be enough shouldn't it?

Will be fine for the shaky

[Nasher]

Tim

The plywood pad will be a pain to keep re-varnishing every year to keep it from looking shabby.

My slant on the situation is that outboards should be mounted directly to the transom. Anything you introduce that can go soft and allow any flexing of the saddle can cause the casting to fracture.

Nasher

[slimtim]

hhmmm, good point. I was going to epoxy it though so I guess it will last a little longer than varnish.

Tim

[Hightower]

Be better with a stainless spreader plate, but direct to the transom for me and you'll never see any damage caused by the installation to the gel coat as it'll be under the bracket. Don't worry too much Tim, if you do develop little stress cracks the stainless route can be done later.

Mines had twins and at least 3 other outboards on the back Tim

[phillnjack]

Some very good advice here.
would never of thought about the ply going soft and causing stress to the brackets



phill

[Nasher]

Originally Posted by phillnjack

Some very good advice here.the ply going soft and causing stress to the brackets

That's the beauty of this forum, others can learn from those that had learnt the hard way.

Nasher.

[phillnjack]

This forum is fantastic.

Its good for newbies and those who have been boating for ages.

Im forever seeing stuff that i had either forgotten ,or never even thought about.
And so many good saftey aspecs

Brilliant forum



phill

[PeterM]

I'm confused about the ply going soft bit . BHG seem to rig all the Yamaha/avon combos with ply between the engine & boat (including mine) , and nearly all sibes have ply ( with no gel) transoms.

Does the ply in these cases take some of the shock away due to 'sqidgeniess' I wonder ?

The bigger boat is mounted with nothing as with most 'bigger' ribs/engines I see?

The question I guess - does size matter ?