repowering my 20v CC have a 150hp 2stroke want to go much smaller

[reelapeelin]

Originally Posted by MoonGlow II

I have a 1980 20v CC with a Suzuki 150 hp 2 stroke runs great and fast BUT the price of gas is killing me and keeping me off of the water. So I am thinking of going much smaller as in the 50 to 90 hp used 4 stroke motors....I dont care about speed as much as having enough power to make it out the inlet in a strong tide and to be safe in case the weather turns bad and the seas get rough. We use the boat for near shore SCUBA diving and intercoastel crusing. staying within 3 miles of shore. Would like to hear all you thoughts on the on my idea. Thanks and happy boating!

Keep the motor you have...gas prices are about to decline somewhat for one thing...and try simply going slower...as you surely will w/a much smaller motor. Keep your RPMs down just enough to keep her on plane...high RPMs really burn the gas...you'll need to juice it up to get on plane, but once you do, throttle back and lighten your load as much as possible...

[willy]

An engine that size will not let you get on plane with the V20, especially with a 4 stroke.
And especially with anything other than an empty lite load hull.
You will use more fuel as has been said but also will use more because you have a hull designed to be efficient at planing speeds, at slow off plane speeds it will be plowing the water.
A good condition 115 hp TWO STROKE!! will be the minimum, they are also very good on fuel. BUT, if you anticipate heavy loads such as people and dive tanks and gear etc. a 150 would be the minimum. IMHO

[THEFERMANATOR]

How fast are you trying to go with your 150? I know teh SUZUKI 150 is the biggest 150 there was at 2.7L's, but it was also said to be decent on fuel for it's size. Fuel burn on it should be around 10-12 GPH or so at a 3800-4000 RPM cruise, a 4 stroke will probably get you down to about 6-9 GPH at the same speeds. And like stated above, 90 is the absolute MINUMUM to get a V on plane. And it won't live a happy life doing it. If you don't boat alot, then you will never get your investment back in buying a new engine. Fuel isn't that big of an expense in all reality in owning a boat when you sit down and add up everything you spend money on when boating. Upgrading engine because of fuel costs rarely if ever pays for itself for a recreational boater.

[bgreene]

Maybe you could rig up twin 50's ?

[Skools Out]

Originally Posted by bgreene

Maybe you could rig up twin 50's ?

not enough but twin 90's would work nicely