correct height of outboard on transom

ian mcconnell · 26 July 2007, 09:39

Ive got a very proven & tested combination of 5.4 searider & 90hp 2st Yamaha, but i fear ive upset its balance by putting fancy consoles & jockey seats on it.

typically with 60ltrs fuel in the main console and with a spare body as ballast on the rear jockey, i'm finding it very hard to trim up at speed without the prop losing its grip on the wet stuff, as the fuel goes down it does get better!!

Also if i intend to do a few tight turns I need to trim the whole way down to stop the prop losing grip.

The outboard is fitted on to the original points on the transom & unless i cut a section off the top of the transom it can not get any lower!! HOWEVER the cavitation plate is a good inch above the water at speed.

Is it worth me lowering the outboard to suit my setup or do all similar seariders suffer the same.

Hugh Jardon · 26 July 2007, 10:29

if this was me i would have a few bags of sand, say split into two bags for each bag of sand

you could put them on the boat and move them around, a bag of sand is around 1£ in the diy places,

drive around moving the sand to different places etc

you can dump overboard any sand not needed and just thro in the bin the plastic bags

it might be that some ballast towards the rear might get things back how they were

worth a try for £5 worth of sand and a bit of time

nikster · 26 July 2007, 11:41

5kg bags of sand in tesco £1.40 in nice thick plastic bags - exactly as hugh says tho - :-)

ian mcconnell · 26 July 2007, 11:49

your probly right guys, only i live in Oxford trust me theres no bags & sand left!!

Hugh Jardon · 26 July 2007, 11:54

i have a few for my flood defences here!!

nearly got caught out !

Hightower · 26 July 2007, 14:45

Go to Wicks and buy a couple of 20kg bags of sand.

genoa · 26 July 2007, 15:15

Quote:

Originally Posted by ian mcconnell

only i live in Oxford trust me theres no bags & sand left!!

But when the summer arrives tomorrow everyone will be happy if you take a few of their hands.

Why does the room still look red? Are those rose tinted glasses still on?

Downhilldai · 26 July 2007, 16:51

Quote:

Originally Posted by ian mcconnell

your probly right guys, only i live in Oxford trust me theres no bags & sand left!!

If you're inclined to go and pinch some, at least you can use the Searider as a getaway vehicle.

ian mcconnell · 26 July 2007, 20:00

i would not dare take them, the local tinkers have been taking the sandbags then they sold them back to the locals in abingdon.

any way does any one reakon i should lower the outboard on the transom to help me with the slip from the prop?

Chris · 26 July 2007, 20:13

Ian, where is the cavitation plate in relation to the bottom of the transom?

Chris

Spike · 26 July 2007, 20:18

Do what all the big boat boy's do when they have the same problem ie; Sunseeker/Sealine/Princess ect ect all put Lead gun shot 'inside' the bathing platform mixed with resin to keep it in place. You can buy it in bag's (not sure where from but Google will know) move em around until you have got it right then when you have you can mix it up with resin (coloured to match the boat's hull if you like) & bond it in & flow coat it to hide it....simple

Spike · 26 July 2007, 20:21

To stop 'Prop Slip' try a stainless four blade prop......worked for me grip's like brown stuff to a blanket!

ian mcconnell · 27 July 2007, 11:37

Chris the cavitation plate is at a very similar level to the bottom of the transom, i guess logically thats about where it should be.

Spike i have got a stainless titan prop, the slip is only when the tank is full or when doing hard turns, the extra weight on the transom seems the only option

thanks everybody

Chris · 27 July 2007, 16:56

Ian, if weight is the problem why not hang an auxilary engine on the transom (if there is enough space)

A Yamaha 4 or 5 HP weighs about 25 KGs.

Or why not fit another fuel tank in the back perhaps under the rear seat pod. I am sure you could get a bladder tank to fit in there.

Then have a fuel switch that means you can use the front tank first then the rear.

Chris

ian mcconnell · 28 July 2007, 08:26

That sounds logical chris, i am having a new stainless aframe made which will be a lot wider than the old one (could not get into the rib by standing on the cavitation plate from the water,to narrow) i guess an auxillary is far better than a bag of sand

The rear seat pod carries 20ltrs already as a reserve.

thanks again

Chris · 28 July 2007, 09:21

Ian, if you can, fit the aux to the transom, its not much use hanging off the A Frame when you really need it!!!

Heres how I have mounted mine. I made up a bracket from the a frame that stops it from swivelling and a strap to the sadlle that holds the engine down tight. It takes less than 10 secs to remove both and have the engine in the water ready to start Yet I happily went wave jumping a few weeks ago with no ill affects to engine or mount.

http://rib.net/forum/attachment.php?...1&d=1181567523

Chris

David G · 28 July 2007, 10:54

Quote:

Originally Posted by Chris

Ian, if you can, fit the aux to the transom, its not much use hanging off the A Frame when you really need it!!!

Heres how I have mounted mine. I made up a bracket from the a frame that stops it from swivelling and a strap to the sadlle that holds the engine down tight. It takes less than 10 secs to remove both and have the engine in the water ready to start Yet I happily went wave jumping a few weeks ago with no ill affects to engine or mount.

http://rib.net/forum/attachment.php?...1&d=1181567523

Chris

Hi Chris,
Have you got any more/better images?

I have an old Osprey Sparrowhawk and have never been convinced there is space to fit an auxilliary without fowling the main.

Cheers,

Orve.

ian mcconnell · 28 July 2007, 11:15

Chris i would only mount to transom unfortunatly with its current aframe i would be luck to squeeze a pencil through the gap.

I guess i will start hunting for a 4/5hp on ebay.

Chris · 28 July 2007, 19:41

Ian dont know whether you want a short or long shaft (probably long shaft) but all these below give you an idea of whats on ebay.

Short shaft
http://cgi.ebay.co.uk/Yamaha-4HP-Out...QQcmdZViewItem

Short Shaft nice condition
http://cgi.ebay.co.uk/Mariner-4-hp-O...QQcmdZViewItem

Nice and perfect as an AUX but will probably fetch £350 or more.
http://cgi.ebay.co.uk/5-hp-long-shaf...QQcmdZViewItem

Tatty 5HP longshaft
http://cgi.ebay.co.uk/5-hp-long-shaf...QQcmdZViewItem

Chris · 28 July 2007, 19:49

Orve

Don't know about the other Ospreys however mine is fairly wide and there is plenty of room for the Aux. The only time I have to be careful is when the main is tilted up and down as if it is turned to the side it will catch however when either or both engines are down there is no fouling.

Chris