possible?

oujakov · 20 July 2009, 04:26

I have a quicksilver 330 air deck and the transom is rated for a 15hp/50kg motor. Most 20-25hp 2-strokers are below that number. I'm thinking to try 25hp on the boat.

Is this trick possible to carry this combo for the long run or it is too much for transom carry?
Has anyone tried it successfully?

p.s. boat gets assembled/disassembled every time at the lake.

9D280 · 20 July 2009, 10:12

Quote:

Originally Posted by oujakov

I have a quicksilver 330 air deck and the transom is rated for a 15hp/50kg motor. Most 20-25hp 2-strokers are below that number. I'm thinking to try 25hp on the boat.

Take a towel....and a change of underwear!

Quote:

Originally Posted by oujakov

Is this trick possible to carry this combo for the long run or it is too much for transom carry?
Has anyone tried it successfully?

At 60 odd % overpower The problem you'll probably have is keeping the nose down & the boat in the water. The bigger HP will shove you along faster, and therefore push more air under the bow. Realistically a bakflip at first sign of a nominally small wave is a good possibility on something that small & light. Also as you'lll spend a lot longer airbourne, the transom will get a lot more of a pounding as you land, and I reckon not do the joint to the toobs a lot of good.

Quote:

Originally Posted by oujakov

p.s. boat gets assembled/disassembled every time at the lake.

a 2- stroke 25 may be as light as a 4- stroke 15, but it's still not excatly an easy lift........ Even my '72 2-pot premix Johnsorude 25 weighs in at a good 3.5 hernias!

Having said all that, if you try it it should be mental fun!

chewy · 20 July 2009, 10:39

What about getting a 15hp 2 stroke, you'll still go quicker due to it been lighter and it'll be easier to setup when you launch.
Saying that I know exactly where your coming andf I'd find the buggest engine within your weight limit and go flying!

http://www.youtube.com/watch?v=gtc2O...eature=related

oujakov · 20 July 2009, 12:25

Good video!

I Did not realize that a flip is not that far away with 25hp!

I guess it is ok to have big block (400cc & 25hp

) hanging of the tail, as long as you don't open it up to wide and start flying.

codprawn · 20 July 2009, 14:12

Probably the best engine of all - but almost impossible to get - is the Tohatsu 18hp 2 stroke - it's the same weight as the 9 and 15hp versions.

I wouldn't worry too much about the extra power - just have someone hefty sitting in the bow.

After all the Avon Jet Rib is only 3.1m and Williams do a 2.85m one - with over 90hp - insane!!!

http://www.williamsjettenders.com/wi...ettenders.html

spartacus · 20 July 2009, 15:54

Quote:

Originally Posted by chewy

What about getting a 15hp 2 stroke, you'll still go quicker due to it been lighter and it'll be easier to setup when you launch.
Saying that I know exactly where your coming andf I'd find the buggest engine within your weight limit and go flying!

http://www.youtube.com/watch?v=gtc2O...eature=related

What was on the back there - a race tuned Tohatsu 50hp?

At least they had crash-helmets on - still scary when it happens though.

Poly · 20 July 2009, 19:20

Quote:

Originally Posted by codprawn

I wouldn't worry too much about the extra power - just have someone hefty sitting in the bow.

After all the Avon Jet Rib is only 3.1m and Williams do a 2.85m one - with over 90hp - insane!!!

Not really though? That would be fairly "typical" for a jetski. But is that comparable to a quicksilver sib? Solid hull, weight distribution (and weight of boat) completely different and a jet will have less efficient use of the power - and I would have thought start to lose power as it starts to become airborne and thus pump air - thus becoming "self limiting", whereas a sib's prop will still be gripping and accelerating.

oujakov · 20 July 2009, 21:30

It looks like weight at the transom is more important with increasing speed when you comparing 50kg Mercury 15hp 4 stroke and 50kg Mercury 25hp 2 stroke.

I'm starting to think that going 25-30mph with 25hp and jumping over the waves can rip the transom away from the SIB!

chewy · 20 July 2009, 22:18

I wouldn't have thought it would.

I spoke to a lad who imported SIB's and whilst he wouldn't condone it he said his SIB's engines were more rated on weight than hp. He said if you found the heaviest 4 stroke that the SIB was rated to then find the most powerful 2 stroke of the same weight it would be fine.

9D280 · 21 July 2009, 13:15

Quote:

Originally Posted by oujakov

50kg Mercury 15hp 4 stroke

and for another few KG you can have a premix 2- stroke 60!!!!!

oujakov · 21 July 2009, 22:17

Quote:

Originally Posted by chewy

I wouldn't have thought it would.
He said if you found the heaviest 4 stroke that the SIB was rated to then find the most powerful 2 stroke of the same weight it would be fine.

Makes sense.

I'm not sure either to get 15hp 2-stroke and be within proper "hp rating" or get 25hp mercury 2 stroke and be within proper "weight rating".

I'm torn between these two choices now..

Do you think it id difficult to handle 50kg motor on and off the car trunk to the lake (100m or so) put onto the transom while boat is in the lake, then do the same backwards when done????

chewy · 21 July 2009, 23:02

Quote:

Originally Posted by 9D280

and for another few KG you can have a premix 2- stroke 60!!!!!

Happy Days!

Poly · 21 July 2009, 23:09

Quote:

Originally Posted by oujakov

Do you think it id difficult to handle 50kg motor on and off the car trunk to the lake (100m or so) put onto the transom while boat is in the lake, then do the same backwards when done????

if you are significantly stronger than me it might be possible. My engine is 48 kg and I can only just get it on/off the transom myself on dry land. I wouldn't even try it with the boat "wobbling" afloat. And if I had to do it every time I used the boat I would probably use the boat a lot less. You would need some sort of trolley to move it 100m.

Sharkbyte · 21 July 2009, 23:33

I reckon you should fit twin 25's.

Thrills aplenty, and it'd be much easier carrying a balanced load over 100m. One engine in each hand. ;-)

oujakov · 22 July 2009, 00:04

Balanced load, it is so sane idea, omg!

On my other boat, I used to have 10hp Johnson 2 stroke long shaft, I guess 35kg or so, I used to carry this motor on and off quite easily. 50kg is only about 50% more weight, quite a lot.....

I guess I should try a demo of motor carrying somewhere

9D280 · 22 July 2009, 10:35

Quote:

Originally Posted by oujakov

Do you think it id difficult to handle 50kg motor on and off the car trunk to the lake (100m or so) put onto the transom while boat is in the lake, then do the same backwards when done????

In a word - yes! I have a similar story with a '72 vintage Johnson on a small hard boat, and I can assure you 50Kg of engine is not a problem to carry 5 or 6 metres, (I fitted my Merc 60 single handed), but outboards are probably the most bog awkward shaped thing to carry....... But then as Polwart says, a trolley cured the problem nicely!

The difference in size between a 10 & a 25 also puts the mass further out from you, making it even more b awkward to lift.

Black · 22 July 2009, 11:43

I've got a Yamaha 20 2 stroke. It is listed at 49kgs dry, and I wouldn't want to lift it more than 30-40ft, and certainly not onto a wobbly boat!

It gives plenty of go on my 380 HD Quicksilver which weighs 100 kgs, about the same as me!

oujakov · 22 July 2009, 15:09

Anyone knows, what kind of spped can you get with 15hp vs 25hp?

In kph/mph

prairie tuber · 22 July 2009, 15:26

Get some pneumatic launching wheels so you can use the outboard you want without having to worry about how miserable it would be to carry it across a sandy beach. Set the boat up beside your car/truck, install the wheels, then install the outboard, and roll the rig to the water's edge. Just make certain that they are the big, pneumatic, 'overkill style' wheels so they can be used on a variety of surfaces (not just showroom floors).

prairie tuber · 22 July 2009, 15:31

"Anyone knows, what kind of spped can you get with 15hp vs 25hp?"

If there is any kind of ripple on the water, and the boat is not heavily loaded with gear, a 25 hp 2 stroke on that boat will bounce you clear out of the boat long before you get anywhere close to WOT.