2-Stroke Vs. 4-Stroke.

[BostonMahhk]

I'm looking to buy a nitro, skeeter, or stratos very soon. This will be my first boat purchase. Can you guys help explain to me the differences between a 2 stroke motor and a 4 stroke and help me decide which will be a better option for me? Thanks guys

[FD.]

In a nutshell:

 

4-Stroke - basically an automotive style engine-  no 2 cycle oil - oil changes like your car - heavier - typically makes less HP per pound - less emissions

I've never owned one but I have friends who love them

 

2-Stroke - The way outboards - dirt bikes - and weed eaters have always been make - you have to add 2 cycle oil to the gas before combustion (either direct injection or mixing in the gas)

I've always had one and if it ain't broke don't fix it

[slonezp]

in addition to above, 2 strokes in many cases perform better, as well as have less fuel consumption. 4 strokes are quiet to operate and don't smell of exhaust fumes. My personal opinion, If you're not going to be trolling, I'd go with the 2 stroke

[00 mod]

Hey slone,

4 stroke should get better gas mileage.

Also, a fuel injected 4 stroke will be muxh less finicky in extreme temperatures.

Jeff

[Snakehead Whisperer]

A 2 stroke doesn't have a valvetrain; so in addition to producing more HP per pound they are much lighter due to the lack of a camshaft, valves, lifters, etc. Iif you're buying a new ob, your 2 stroke choices will be limited. 

[slonezp]

Hey slone,

4 stroke should get better gas mileage.

Also, a fuel injected 4 stroke will be muxh less finicky in extreme temperatures.

Jeff

Based on my research when I bought my boat, the ProXS fuel consumption and top end was better than the Verado. That is what I based my statement on. Mercury's website has a ton of engine test data of different motors on different hulls..

 

The OP has 3 hulls listed The nitro will come with a Merc, the Skeeter with a Yammie, and I believe the Stratos will give him a choice of powertrains depending on the dealer.

 

EDIT: Here's 2 links same HP similar hulls http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=493&

http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=244&

[Snakehead Whisperer]

Based on my research when I bought my boat, the ProXS fuel consumption and top end was better than the Verado. That is what I based my statement on. Mercury's website has a ton of engine test data of different motors on different hulls..

 

The OP has 3 hulls listed The nitro will come with a Merc, the Skeeter with a Yammie, and I believe the Stratos will give him a choice of powertrains depending on the dealer.

 

EDIT: Here's 2 links same HP similar hulls http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=493&

http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=244&

Your post reminds me of something. 

 

OP... you're most likely going to have to run 92 octane if you go with a 4 stroke, where as most of the newer 2 strokes will run fine on 87. 

[00 mod]

Based on my research when I bought my boat, the ProXS fuel consumption and top end was better than the Verado. That is what I based my statement on. Mercury's website has a ton of engine test data of different motors on different hulls..

 

The OP has 3 hulls listed The nitro will come with a Merc, the Skeeter with a Yammie, and I believe the Stratos will give him a choice of powertrains depending on the dealer.

 

EDIT: Here's 2 links same HP similar hulls http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=493&

http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=244&

 

 

Fair enough,

 

When I was looking, which I might add was several years ago, the 4-stroke had the better fuel efficiency for my application.  (same test data from Merc)  I guess that is why they make so many of both!

 

Jeff

[00 mod]

Your post reminds me of something. 

 

OP... you're most likely going to have to run 92 octane if you go with a 4 stroke, where as most of the newer 2 strokes will run fine on 87. 

 

 

My 2011 Merc 4 stroke is rated to run off 87 with a M15 rating( which means it can handle gas with up to 15% methanol)

 

Jeff

[Snakehead Whisperer]

My 2011 Merc 4 stroke is rated to run off 87 with a M15 rating( which means it can handle gas with up to 15% methanol)

 

Jeff

Well that's news to me. Most of the 4 strokes I've seen have a 92+ sticker on them.

[Jig Man]

If you go for a 2 stroke be sure to get the direct injection engine not electronic fuel injection.  They are as easy on gasoline as 4 strokes.  I have been running the same 2 stroke direct injection engine for 11 years and if I keep the rmps 4500 and below it gets very good mileage.  WOT is a whole different issue but I don't fish derbys so I rarely need WOT.

[ww2farmer]

Well that's news to me. Most of the 4 strokes I've seen have a 92+ sticker on them.

FWIW, on my small 4 stroke ( 2006 Merc. 25hp) the performance and fuel consumption is noticeably better with 93 octane than with 87. IDK why, but it is. I have never noticed it being any better in any cars/trucks I have had, but it is with the outboard. I don't use 87 any more at all for the outboard.

[slonezp]

One thing that wasn't mentioned. I'm not sure about the smaller hp motors, but when I was shopping, the 225 Verado was $2500 more than the 225 ProXS

[Snakehead Whisperer]

FWIW, on my small 4 stroke ( 2006 Merc. 25hp) the performance and fuel consumption is noticeably better with 93 octane than with 87. IDK why, but it is. I have never noticed it being any better in any cars/trucks I have had, but it is with the outboard. I don't use 87 any more at all for the outboard.

Good to know. I have a '87 Merc 25hp, and haven't noticed any difference with high octane gas, so I always run 87. Do you know the weight of your engine? Mine is right around 85lbs. 

 

I have no idea what ignition system the newer 4 strokes have, or the compression ratio on them; so hard to say why it is that you have such a noticeable performance/economy boost with the higher octane. Bottom line is that higher octane fuel is actually more stable/less volatile than lower octane, so getting better performance just from the high octane fuel alone is not likely. If it's a higher compression engine, or has a a lot of advance in timing then it was probably not designed to run on the lower octane fuel.

[00 mod]

Just went back and looked to make sure I am not ruining my engine, and the recommended for mine is 87 with 10% or less.  So I was wrong abut the 15%.

 

http://www.mercurymarine.com/engines/outboards/

 

Jeff

[S Hovanec]

The book for both of my Hondas says to run 87, with no more than 10% ethanol.

I find it funny that when comparisons between 2 stroke and 4 stroke fuel efficiency are made, they never use a Honda as the 4 stroke being compared.

[BostonMahhk]

The boat I'm looking at is an 05 nitro nx882 with a Merc 150 xr6. How do you guys feel about it?

[BostonMahhk]

I only ask cause I heard the xr6 was one of mercurys most reliable engines

[J Francho]

The XR6 is a good motor.  Carbed, so cold starts are a pain.

[BostonMahhk]

Which will last longer when maintained correctly?

[slonezp]

I have a 2 stroke from the 60's that still runs. There are older ones as well. Maintained properly,  generally 2 strokes are pretty bullet proof. FYI carbed Mercurys hate cold starts just like J Francho said. The newer 4 strokes get great reviews as well. Finding a mechanic who can work on a 4 stroke may or may not be difficult.

[Dwight Hottle]

The book for both of my Hondas says to run 87, with no more than 10% ethanol.

I find it funny that when comparisons between 2 stroke and 4 stroke fuel efficiency are made, they never use a Honda as the 4 stroke being compared.

 

 

They never use the Honda 2 stroke either!

[S Hovanec]

Which will last longer when maintained correctly?

 

 

There have been reports of the Coast Guard having up to 10,000 hours on some of their 4-strokes.  Doubt you'll ever find a 2 stroke that will do 1/4 of that.

[FD.]

Which will last longer when maintained correctly?

 

You would be shocked at how FEW hours you actually put on the gas motor a year in a true fishing boat.  I have a 250 Pro XS that I fish 12-15 tourneys a year and hits the water nearly every weekend and gets less than 100 hrs on it a year.  Compare that to the trolling motor which gets probably 500 hrs a year.

 

The average life span of a well maintained marine motor is upwards of 1500 hours before a major overhaul.  It's not likely that you will keep the boat longer than the life of either motor.

[Sam]

Stay away from Evinrudes.

 

Check out the cost of the oil per gallon for the motor you are considering.

 

4-strokers are BIG. Like having a refrigerator following you around.

 

Check out the octane level needed for your motor.

 

If you get a Nitro try to find a professional motor service shop in your area that will service your motor and stay away from the Power Pro people.

 

Just my two cents.