Saving Old Seagulls

Hi from Maroochydore, QLD, Australia.
I'm Al.
So, I was given a little boat recently. She's a 10ft tinny with a displacement style shape (As opposed to a flat 'punt' style tinny.)

I have little experience in boating etc but the offer of a free boat with all the awesome fishing in the waterways where i live was too great to turn down.

So I fixed up the boat , got the trailer going and looked for an outboard. .

"You can have this " said the father in law.. And produced a seagull from his shed. Proper nice bloke my F.I.L..

WSPCL 623HH7. (1977 silver century plus, long shaft clutch, yes??)

Well. I like to research so I now known a bit about these old motors. Enough to get the old beast running pretty well and looking relatively tidy. It only needed a good strip and clean and the cooling impeller turning the correct way round so it actually pumps water (Yes, really. Ha ha)

Anyway. Me and the Mrs had a good 3 hours out on the water today and apart from the sunburn and the clogged fuel filter .. (should have cleaned the tank better, quick blow through and we were away again ).. It was a great day. Superb little motor.

But my.. she's slow. .
This is a 10 foot ally boat, so light I can pick it up over my head, two people on board plus picnic and fishing gear.
Top speed on the GPS is 7km/h in still water with a light cross breeze . It seems to run fine and revs its tits off at full throttle. Earplugs at the ready. Ha ha

Isn't that a bit slow though ?

I know these motors are not designed to push quickly and I'm certainly not expecting to get up on the plane, but being overtaken by a 10 year old on a stand up paddle board is somewhat embarrassing.

Is it...as I suspect. ..because it's a long shaft on a tinny? Is it too low? Am I wasting thrust trying to rotate the boat on the pitch axis, lifting the front rather than pushing along?

Shall I lift the seagull up? Is that a good idea having an extension board on my transom or should I give it back to the father in law and swap it for the forty plus standard shaft that's also in his shed?

Or is 7km/h about what I can expect ?

Anyway. . Sorry for the long post.

Hello again

Can you post a picture of the propeller?

Charles uk wrote:Can you post a picture of the propeller?

Yes I shall do that in the morning
On the boat yes?

No we need to ensure you have the right lower unit & the right prop, "revs it's tits off" is an unusual description for a Seagull.

Charles uk wrote:No we need to ensure you have the right lower unit & the right prop, "revs it's tits off" is an unusual description for a Seagull.

Ha ha.
I meant it sounds to be easily revving as high as it was ever designed to go. no struggling.

I'll snap that pic asap.

Thanks

Al.

I would say that its too deep in the water.
I have the same problem on a FP and have since bought a FPC and converted it to extra short shaft!
Now powers the 8ft dinghy perfectly!

Jacob

Ok. So I'm not at home so can't take a photo but a quick bit of research revealed this... (hope this works )
So that is what the foot looks like but not the prop.
The prop looks like this. ..
So I have a 'weedless ' on there? Is that 'wrong '
?

I will still snap that pic for clarification.

Al.

Your prop should have "CLW" cast in the spring notch.

British Seagull had a word or two about this Your 3.8 knots is close to their 4.5. Your ten foot tinnies hull speed is 4.2 (7.8 km/hr) so you are almost there.

I've had similar woes with my 17 footer. My wspc originally had a weedfree prop fitted to it which i thought was pretty well suited to my particular boat, but when i fitted a hydrofan prop to it MY GOD it was awfully slow by comparison. Nothing wrong with how my motor was set up on the back at all, but the prop i felt wasn't quite right somehow.To see if it was just 1 rogue prop i tried 2 other 5 bladed hydrofans with similar slow results. Switching back to the weedfree prop brought things right back to how it was, pushing the boat to near perfect hull speed. Never a truer word said about matching the motor (or in my case the prop) to the boat. Mind you my boat is fairly heavy so i don't expect to go very fast with even the very best seagull on the back.

As you've suggested i'd look for a nice 40 plus which might be better suited to a smaller boat like yours.

Jon

So Jon...
I'm just asking to get this correct in my own head.
Are you saying the weed free was better than the hydro fan? Or the other way round ... the hydro fan was better than the weed free?
I know every boat is different and what work for one may not work for another.

Hi.
Thanks for the replies and advise peeps. Looks pretty much like I'm just expecting too much :/ . I mean; one has only to watch how slow that big *rse prop goes round and round to realise these beasties are geared for torque.

Anyway. Sorry for the delay , my phone went for a swim. As promised, here are some pictures (excuse bad camera on phone )
Prop
I have been experimenting with different mounting heights . This is where I am currently which might be a little high as...
The higher cooling water inlet is above the bottom of the boat (although still well in the water)and I am no longer getting my nice thick water flow right through the rev range.

As you can see though, this is a fair bit higher than I originally had it on the boat's standard transom. Also. Here is my exhaust tube length. Is this a standard long shaft or has it been modified? Apart from seeming to effect cooling flow, where I currently have the motor will get me a choppy 8kmh one up in the boat. That's just fine but I want to fine tune.

I don't know much about boating but I reckon that even if I invested in a modern 3.5hp unit, I probably won't go much faster. Anymore than 4hp here in Queensland and the boat needs to be registered. Any more than 6hp and I need a boat license. These are both expenses I don't need for my tiny 10ft tinny fishing setup.

Also. .Thoughts on this.. I want to put a peice of air filter sponge material over the storm hood to reduce induction roar and also put a couple of hose clamps around those holes in the exhaust tube. I reckon that will make it quieter without much detriment to reliability or running? ??
Al.

Blocking the holes in the exhaust tube will make a big difference!
Not sure what putting foam in the carb will do.

There is a 5 blade hydro fan that will fit that gearbox that Might make it a bit quicker...

There is a pic of one in this thread. (first pic of a prop)
viewtopic.php?f=2&t=5592

"The higher cooling water inlet is above the bottom of the boat (although still well in the water)and I am no longer getting my nice thick water flow right through the rev range."

Ok do as below and try again......
BnC

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