Pontoon Boat & Deck Boat Forum

Rookie questions about 4 stroke vs. 2 stroke motors. Hp for hp does one out perform the the other and is their any difference in fuel economy?

Both are very good these days. My E Tec is way better than my old Merc 4 stroke but with EFI they are great. 2 stroke is lighter... than 4's

I went from a 30 horse 2 stroke to a 25 horse 4 stroke and for what it's worth I gained a ton of low end torque with the new motor. Now this may be related to different props but I also really like how much quieter the 4 stroke is... In myopinion for limited horsepower lakes like mine it's 4 stroke all the way!

With the newer fuel injection technology both on 2 stroke and 4, the only real thing to think about is how you will use your motor.

If you will run the motor in the upper half of the RPM range most of the time- 2 stroke and 4 stroke will be fine.

If you will spend many hours at just above idle - I would opt for a 4 stroke

Thanks for the info guys. I'm usually running my two stroke at about 3800rpm so kinda of a wash for me.

How much are you going to use it, a four stroke you have to change the oil whether you use it or not, my 50HP 91 two stroke is still doing fine, the only reason I changed is for another fourty HP with a 2001 90 Mercury.

2-stroke's easier to do your own repairs/maintenance on, IMO

With the purchase of my 70 four stroke Yamaha I will never even consider another 2 stroke. Not that's its gonna be a huge issue with 2 strokes becoming more and more obsolescent each year.

IME the economy , ease of maintinence and quiet power of the modern fours are vastly superior

4 strokes--quiet at low and medium speeds, smooth, better fuel mileage. Get loud at full throttle and require an oil change yearly. More expensive to buy.

2 strokes--relatively quiet at low speeds but get louder at medium speeds, faster acceleration from a stop, lack of oil change is offset by having to put expensive oil in a tank. ETEC HO's and Mercury Pro XS outboard motors are 10% underrated on horsepower and will be maybe 3 mph faster on top end than the same hp 4 stroke.

If someone's into water sports, going with the next smaller size 2 stroke ETEC HO or XS Pro is a good value option because 2 strokes are so strong in acceleration. For example, a 115 hp Pro XS will pull as hard as a 150 hp 4 stroke when getting a slalom skier from deeper water. You can save $3K with the 115 hp Pro XS vs. the 150 hp 4 stroke.

Take it a notch farther. My local Mercury dealer sells the 150 hp FourStroke for $9950 (without controls). Yamaha F150's will cost you about $13K. A Mercury 115 hp Pro XS is about $8K, or $5K less than a Yamaha F150--for about the same pulling power. The Merc 150 hp FourStroke must also be popular, as they're on backorder. That said, I'm still not sorry I went with Yamaha.

I'll start off by saying i love my 06 Mercury 90 four stroke(Yamamerc). Quiet, starts up everytime, no choke, good on fuel, etc. It was my first four stroke outboard i've had and i don't miss my old 2 strokes. However, I can't comment on the newer E-tecs, pro xs's, etc. But i've heard they've come a long way with fuel efficiency, reliability, and the incorporation fuel injection. I will say that my 4 stroke does not seem as "snappy" or "torqy" compared to 2 strokes, but it loves rpm. I like changing the oil yearly rather than constantly adding expensive oil to a reservoir or mixing.

You can buy a new Yamaha V150TLR Outboard Motor (150hp) Two Stroke V MAX Carb for $7995.00.

You can buy a new Yamaha F90LA Outboard Motor (90hp) Four Stroke Midrange for $8230.00.

http://www.boats.net/pages/MotorBlowout.html



In my opinion - if your motor is going to be sitting idle for loooong periods of time I would opt for a two stroke ANY day. As others have said, if you are spending more time cruising at low to medium speeds the four stroke would be more "comfortable" and a HECK of a lot more fuel efficient. Two strokes are VERY happy at WOT. Don't forget there is a significant weight penalty - and more involved maintenance - with four strokes. Generally speaking four strokes will last longer than two strokes.

I've got a 1988 Yamaha 90 two stroke, and with modern synthetic 2 stroke oil and the proper heat range spark plug, well synched, balanced and freshly rebuilt carbs it smokes VERY little. It's still very dirty by modern standards, but it isn't obnoxious by any means - except on cold start for a minute or two - until it warms up and the rings seal better.

IBoats looks like a pretty good place to buy a motor. The above link is to a website that does give you price comparisons.

Some of the motors are at great prices, but some motors can be bought a little cheaper. I would think that most of the dealerships with these motors are in middle Florida, and it's always best if they installed them.

And that 150 VMax carb. motor is a great price, but an old model new motor. It'd do the job but not get the fuel mileage that the more modern motors would get.

I would always try to buy a motor from a dealer that's close by. But sometimes it pays to go elsewhere if your local dealer's unwilling to compete for your business with a fair price.

MPosey519 wrote:2-stroke's easier to do your own repairs/maintenance on, IMO

My E Tec isn't do it yourself friendly. Without computer to read vitals they can be spooky.