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Author Topic:   Four stroke vs. Optimax
Debyser posted 07-27-2004 10:03 AM ET (US)   Profile for Debyser   Send Email to Debyser  
I have posted this subject several times but perhaps in the wrong forum. Maybe now I can get the required info.
I am repowering my 1986 montauk . The only alternative in my home country is mercury.(good service and stock of parts). I am extremely confused with four stroke vs. optimax. After researching a bit, I decided on 115 hp.vs 90 hp. My uses are, Fly fishing (no speed needed), and water skiing. I have read many threads on this subject but they mainly concentrate on propellers, and not so much on engines. Your experiences and observations are appreciated so that I can make a more intelligent decision. Because of local duties, taxes and freight, the engine runs over US$ 10000. So this can be a costly decision. I have to make up my mind before september since our season starts in december.
Many thanks
Sal A posted 07-27-2004 10:29 AM ET (US)     Profile for Sal A  Send Email to Sal A     
The 115 Mercury 4 stroke (which I have on my 190 Nantucket) very well may be too heavy a motor to put on your older Montauk. The 90 4 stroke is done often enough, and I imagine that engine might still be a bit heavy, if only marginally. The acceleration of a 90hp 2 stroke would probably better that of the 4 stroke, but I can't imagine any of the 90hp engines, 2 or 4 stroke, being a dog on your hull. Heck I tow tubers with my 115 4 stroke on my significantly heavier boat.

Just passing on what I have hear here in the past, and I hope more informed members will chime in to help you.

Debyser posted 07-27-2004 10:58 AM ET (US)     Profile for Debyser  Send Email to Debyser     
Thanks Sal A. I really do need the speed for water skiing.
If 90 HP is the engine, then the optimax,according to the dealer will get to the required speed faster than the four stroke. Is that correct? Does it really matter that much?
Jim Bennett posted 07-27-2004 11:16 AM ET (US)     Profile for Jim Bennett  Send Email to Jim Bennett     
Others in this forum more knowledgeable than me on this but my 2 cents.
"Does it really matter?"
Think either engine would do fine but size of and number of skiers you plan to tow makes hp and right prop important considerations. Getting skiers up quickly is more important than top speed both for your engine and for skiers fun.
TampaTom posted 07-27-2004 07:47 PM ET (US)     Profile for TampaTom  Send Email to TampaTom     
I don't have experience with 4 stroke outboards, but I like what I don't hear (they are quite.) Generally 4 stroke is heavier and less torque out of the hole. However, the Optimax seems to be only 10 lbs lighter than the Merc 4 stroke. Before the advent of direct injection (Optimax), 2 strokes less complicated.

For skiing, I'd need the 115 to get my fat ass out of the water on a slalom ski.

Why not get a classic carb 2 stroke?

I've been to Santiago. Great place. I'm getting the urge for cerviche and a Pisco sour.

AQUANUT posted 07-28-2004 01:21 AM ET (US)     Profile for AQUANUT  Send Email to AQUANUT     

the mercury 115hp 4s EFI and the carbed mercury 90hp both weigh approx. 384lbs
the 115hp mercury optimax weighs only 24lbs less.

it is always a a weight vs hp issue isn't it.?
..the opti is comparatively as quiet as the 4 strokes with the exception of some air compressor noise that is heard at idle

apples or oranges? pick your flavor

Aquanut out!

Debyser posted 07-28-2004 12:34 PM ET (US)     Profile for Debyser  Send Email to Debyser     
If both engines work ok, and no issues regarding functioning arise then I would definetly go with the lighter one. 12 kilos on the transom do make a diference in my opinion.
Tampa Tom: 2 stroke is definetly out since pollution restrictions are coming into effect on lakes in Chile as of 2006. Besides I still prefer to hear my wifes cranking than the engine"s. Maybe I will change my mind later on.
Glad you enjoyed Santiago with ceviches & pisco sours.
Aquanut&Jim Bennett: thanks for your interest in helping.
Sergio Furman

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