what would happen?

mudslinging79 · Aug 3, 2010

i recently picked up a west marine 10 foot inflatable, pvc i believe, and am planning on using it for my racing sib. the weight cap is like 920 pounds, rated for a 9.9 horse. my question is, other than legal aspects, what would happen if i were to put a 1965 18 horse on it, as its all i have at the moment?

Sea Rider · Aug 3, 2010

Re: what would happen?

An actual 18 horse weights same as any 10/15 HP engine so weight on transom no big deal. Not sure about a 1965 horse, anyway what's the weight ?

As an example Zodiac/OMC 305 uses a 10 HP engine, but can be used with a 15 HP with no problem at all as both engines weights the same. Just inflate your sib and keel well to it's working pressure, move passengers forward to at least middle sib and test for yourself.

If you are not a experienced boater take it with calm, throttle in increase steps, experiment different accelerations to plane the sib, tame the beast gradually until you have confidence on what you are doing. But overall, Sib Safe!!

Happy Sibbing

Whoopbass · Aug 4, 2010

Re: what would happen?

Nothing is going to happen. There's pic's here of a guy that has I believe a 55hp on an inflatable about the same size inflatable.
18hp will push it about as fast as you will want to go unless your actually going to race it.

deejaycee_2000 · Aug 4, 2010

Re: what would happen?

nothing will happen indeed, I run a 30hp modified motor on a 8,5 ft inflatable, a 50hp on a 10ft and a 90hp on a 13,5 ft inflatable .... so overpowering is my game ... i love it (",)

mudslinging79 · Aug 4, 2010

Re: what would happen?

cool. im allowing about 200 pounds for me, another 150 for the motor, weighing both heavy, so im within the weight limits. was concerned with too much power but that does not seem to be an issue. maybe ill get a chance to try it out in a few days.

jspringator · Aug 4, 2010

Re: what would happen?

That 18 should weigh less than 80 lbs. I used to have a 25 that is a souped up version of that motor. I bpoght it because it was the lightest 25 available.

mudslinging79 · Aug 6, 2010

Re: what would happen?

good to know, i was estimating weight on the heavy side to be safe, was worried bout ripping off the bottom or something like thast, as i dont like to take an unexpected swim.

MEK · Aug 8, 2010

Re: what would happen?

I bought a suzuki 30hp 2 stroke for an upcoming upsize in boat. I planned to pick up the new boat on vacation to save shipping costs. I wanted to prove the reliability of the 30 though first so I took it out for a day on my Walker bay 340 air floor (11 foot). Wow, I normally power it with a 15hp johnson 2 stroke and it was no comparison. The motor weighs twice as much so I wouldn't want to bounce it through waves mind you. The power overcame the airfloor though with myself and my 2 children. Once I could see it bulging too much I'd back off a hair. I've only seen the air floor bulge before with a lot of weight in the boat or the floor under inflated.

Sinistre1 · Aug 8, 2010

Re: what would happen?

Hey MEK, just out of curiosity how fast were you going with the 30 and how much does it weigh, oh yeah and is it two or four stroke? Thanks. Ooops, forget the last part, Isee it is a two stroker.

MEK · Aug 8, 2010

Re: what would happen?

Hard to say on speed, 30kmph at 1/4 throttle? Much more than that and I started getting water coming over the transom and the floor bulging. I'd guess 150lbs on the 30horse.

I just posted that first post for Mudslinging to back up DeeJaycee saying take it out and try it, its fun.

mudslinging79 · Aug 9, 2010

Re: what would happen?

dont think ill have to worry bout the floor bulgng as its the wood with an inflatable keel piece, ounds like fun. waiting to get it licensed, thety want 65 bucks. 30 for the title fees and 3 bucks a foot with a 5 dollar invasive species tax.

deejaycee_2000 · Aug 11, 2010

Re: what would happen?

I push my 30hp to 76km/h ... lots fun hahaha

mudslinging79 · Aug 11, 2010

Re: what would happen?

i see some have souped up motors, how is that done? boring out the cylenders?

Sinistre1 · Aug 11, 2010

Re: what would happen?

Thanks for the reply MEK. Sounds like it might be wicked fast if you could open 'er up!

deejaycee_2000 · Aug 12, 2010

Re: what would happen?

There is alot to do if you wanto soup up the motor ..... porting, change jets, mod exhaust, race reeds, race oversize pistons, shave head, advance timing, lighten flywheel, weld crank, remove rev limiter etc etc etc ....

GTpopper73 · Aug 26, 2010

Re: what would happen?

Just to get things straight.. so if i were to use a 9.9hp 2 stroke on my Avon R2-50 which is rated for only a 5hp, it should be okay?

Thanks

Sea Rider · Aug 26, 2010

Re: what would happen?

GTpopper73 said:
Just to get things straight.. so if i were to use a 9.9hp 2 stroke on my Avon R2-50 which is rated for only a 5hp, it should be okay?

Thanks

You can place it, but the sib is too small for that engine, will need to be at a prow mask position to plane that thing.

Happy Boating

GTpopper73 · Aug 26, 2010

Re: what would happen?

Thanks again sea rider but what is 'sib' and 'pro mask'.. Ha ha.. sorry.. just got into all just a week ago... still a lot to learn!!!

TOHATSU GURU · Aug 26, 2010

Re: what would happen?

SIB is a rarely used European slang word for soft inflatable bottom...It's not term used in the U.S. "Prow mask" probably means that you need to be at the bow of the boat with your face extending over the bow like a mask. That would help to counteract the fact that the engine is too large for the inflatable and would make it very difficult to plane. And you will tear that R2.50 apart with a 9.9. The transom is thin on that model and the boat was only designed to be used as a put-put.

GTpopper73 · Aug 26, 2010

Re: what would happen?

Thanks a million...

what would happen?

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