Glen-L.com

Hey, get this, I can remember when gas was under 60 cents/liter, and I'm only 19! Amazing how fast the world can change isn't it? My father can recall $5 tank fill ups, from dry! I just don't know how guys runnin twin 250's or wake board boats, or even PWC's can afford it! Oh yes, thats right, we live times of easy credit. Thats why i love the little outbords. They will run almost forever, sip fuel and still provide great memories for your buck. [/i]

Couldn't of said it any better myself. My 40 4 stroke gets the same fuel mileage as my 9.9 2 stroke. There was a thing in December 2007 that apparently gas was going to make itself down to 80 cents/L in August, in Canada, Ontario, Toronto. But obviously that was a lie.

I don't understand why the big car companies and boat companies are still making giant sized boats/cars with giant sized engines. Like Ferrari's...nice car wouldn't buy it if I had the money..gets 8mpg city 11 highway. Hummer should just quit and go home.

They are making a law where I think at either 2010 or 2012 ALL giant sized diesel and gasoline running aircraft carriers, etc. are going to be powered with nuclear engine(s). Don't have to refuel..well every 20 - 25 years!

Audi recently figured out how to do a complete burn on a diesel with piezoelectric something or other. Its an SUV engine that provides 226hp with 452lbs./ft of torque. Still getting 20 mpg (city) and 24 mpg (highway) mileage. But yet again stupid price. Maybe they will share their technology with Cummins, Yanmar and Volvo.

I would love to buy a nice SUV or car but I'm sticking with the high mileage Echo (yes I know its dumb) or something along those lines. 41mpg highway and 38 mpg city sounds good to me. Sure it can't pull but I'll have to live with it for a year or so.

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Tuffy with '75 Merc 650 SS.

Since we've rambled on about different arguments...I wonder what else would make Andrews boat go a little faster. I joined Scream and Fly forum almost 7 months ago and some one told me if you take a total of 100lbs out of your boat you will gain 10mph. Thats only true for some boats though obviously.

But to increase speed:

Ultra smooth, low friction bottom
Fiddle around with prop sizes
Engine power to weight ratio
Appropriate weight distribution
Lightweight Hull
Stream line
Increase Engine HP

Thats all I can think of right now.

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Tuffy with '75 Merc 650 SS.

hmmm...so if i were to subtract my weight from the total, i could see some real gains! oh yeah, guess the boat still needs a driver I forgot about sream and fly, i should join their forum too.

Andrew
How high are you running the engine on the transom?

Try raising it up a little at a time & you may see some increase in speed.

On my old TNT, I used to set my Marc 35-A Mercury up on a 1x2 on top of the transom so the cavitation plate of the motor was level or just a hair above the bottom of the boat.

Depending on load & use,you can go up a little higher than that as long as you are still getting cooling water& aren't cavitating.

You should pick up some speed this way.

If you would like to try an adjustable jack plate to vary engine height,here is a link to one you can build:

http://www.dillon-racing.com/jackplate/index.htm

You will probably have to run a larger pitch cupped prop with the increased height.

Keep us posted on the results!

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Boat building can best be defined as an endless series of
tragedies obscured by the occasional miracle, followed by a good bottle of beer.

Don't Dream Your Life, Live Your Dream

Scream and Fly is an awesome forum. So much feed back within near to the hour of posting. A couple people post stuff that is just stupid but most don't. There is a Canadian boating site just for fast rec. or real racing boats. I forget the name but I'll find it out sooner or later.

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Tuffy with '75 Merc 650 SS.

Scott,
That wouldn't be http://www.muskokaseaflea.ca/ would it?

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Boat building can best be defined as an endless series of
tragedies obscured by the occasional miracle, followed by a good bottle of beer.

Don't Dream Your Life, Live Your Dream

I have considered the idea of a jack plate, and given my set up was proper, increased speed may be possible. The reason i haven't pursued the idea is because i was concerned about the effects on the boats manouverability. Without a doubt, i would need to change props. Currently my antilventilation plate rides about 1" below the hull bottom. I once tried an 18" pich stianless chopper prop (i forget the diameter, but it was bigger than stock props) with substancial rake and cupping. The result was very slow acceleration (due to prop slip) and a lower top speed. To make a prop like that work, i think raising the motor would be the only way to get the desired results. The funny thing about that prop was, the owner apparently had it custom built for his 25 on an 18ft pontoon boat! Surprise, surprise it was usless, and it became a coffee table decoration.[/u]

Nope it is something else. I'll find it one day soon and post it on here. Ah, never mind just found it! http://www.fastboatscanada.com

Its another forum but for well read the link. I haven't joined it yet though.

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Tuffy with '75 Merc 650 SS.

What kind of reeds did you replace your old ones with?

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Tuffy with '75 Merc 650 SS.

I put in some two stage, fiber reeds called Boyesen reeds. I did this for a couple of reasons. For one, those 25 mercs like mine are notorious for eating there origianal metal reeds(mine was fractured and soon on the way out). When running the motor beyond its rpm limit the way i do, this possibility increases. So, i went with the fiber ones so if they blow, it wont take out my crankcase and pistions. The second reason, as you probably guessed was for power. In truth, i don't think there was much diff with the 25, my 9.9 on the other hand was a different story. Well actually, don't tell anyone one , but its really a 15, i changed the carb and exhaust header years ago. With the Boyesens' i put in it, i would estimate that its now an 18 or even a 20. I saw about 28.5 mph on gps (two faster than the old reeds) which isn't bad for an heavy fishing boat.
Scott, you should consider putting them in your 9.9. I know its the old 210cc block, but it might still add a bit of kick. I got mine for 50 bucks or so, and for the protection alone it seemed worth it.

Nice nice! Yeah I was wondering why you went so fast with your 9.9 horse. My 9.9 is on its way out the door soon but I am probably going to take it apart and convert it to a 15. I've always wondered how to do that...guess now I know. It really needs a fix...badly. Some how last year water got into the cylinders.

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Tuffy with '75 Merc 650 SS.

Water in the cylinders on an outboard? I know that can happen to sterndrives when manifolds crack, but on outboards you usually have to submerge them. I can't remember if those engines have one piece block/cylinder head assemblies or not, i'd have to look at mine. You've probably thought out all the possibilities already, but if the cylinder head gasket leaked in conjunction with the cooling passages....well it could be more simple than that, just keep the cylinders full of oil until its fixed!
Anyways, to convert your beast into a 15 could be a little tricky. My engines the later 265cc block which could come from the factory as a 15. Yours to my memory is the smaller 210cc design, which i think was made into a 9.9 at biggest. Don't let that bother you, I'm willing to bet there is a good aftermarket or those series of engines. There could even be some sort of racing kit for your engine, right know i don't know, i'll research it though.

I will probably just forget the upgrade and do a full clean up and inspection.

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Tuffy with '75 Merc 650 SS.