O/B motors 2 stroke vs. 4 cycle

[catalyst27]

I have a Catalina 27 sailboat recently purchased, came with a 2 stroke 9.9 yacht-twin long shaft O/B well the time has come as the motor is on its last legs (repair will cost as much as a new one) this came from a very honest repairman whom I trust. Now the question is which to go with, I have heard good and bad about both and even conflicting info from salesmen about both

1. Is the boat rating according to weight of the engine as the 4 cycle weighs more then I would have to have a lower horsepower thus losing power and speed

2. I have been told that the 4 cycle is more efficent and could go with a lower horsed engine (silly me I tought that the propeller was the magic key here)

This type of sail boat has a open trasom instead of a engine lift so mounting would be infrequent so fueling should be a factor as well

So I ask for your comments and opinions as i value your thoughts on this matter so many years of seamenship under one roof

[sailingfool]

If you can still get the 2 cycle where you live, I'd go with another 9.9, typically cheaper and lighter for the HP delivered.

[Cruisingdad]

I have owned several of both.

The 4 is quiter and runs cleaner. No mixing. I have heard the argument about it having more torque or something and thus needing a smaller engine... but I am not sure I buy that argument. The 4 is heavier but they do have some newer "lightweights" that have come out. I have not used one though.

Another big plus of the 4 is the RPM you work at. My old 2 stroke really liked to be run wide open (as I undersatnd all 2's do). A 4 can really be run at any RPM just fine - which is great as my only use is for the dinkk and we often run at low speeds.

Going back, I would still buy a 4 because it is better on the environment, can run at lower rpms without issues, is quieter, and I do not have to mix the gas. The only thing I would change is I would probably buy a lightweight.

Just my opinions. Others may dissagree.

- CD

[eryka]

I'd echo what C-dad said about the 4s running cleaner, quieter, no mixing. Didn't know about the 'any rpms' but that's great to know, since we also use it primarily for puttering in the dinghy.

If you intend to stay in the US, I understand that under pressure from EPA the 2s are being phased out? This may influence your ability to get parts & service down the road?

When we bought our 4-stroke 9.9 horse 3 years ago, IIRC the weight penalty was about 15% heavier than a similar 2-stroke.

[camaraderie]

In the USA...I'd now go for the 4 stroke for all the advantages noted above. Outside of the USA I'd do a two stroke for repairability and parts availability.

[ebs001]

Pretty hard to find a new 2 stroke for sale in North America any more.

[Jotun]

If you are truly interested in the two-stroke, then you might consider buying a used one if you can't find new. There are many almost new motors available and you will save a lot of money. I have owed many two-strokes and have been happy with them. I have heard that four-strokes can be problematic, but this is all hearsay. I have however seen the lower 8hp 4 used in place of the 9.9hp 2, which I guess is due to the difference in weight.

[Shack]

I have a 2 stroke on it last legs right now. It hangs on the back of a little Cape Dory. I'm gonna run it till it dies and then get a 4. Its a little 1997 5hp Tihatsu! Try and find parts for that thing!

Whenever moving parts are involved I look at some commonality and available parts and labor. (I am a logistician at heart.) So, I'm trying to get a good deal on a 5 or 6hp Mercury 4 stroke.

Although my needs right now don't require alot of hp. I only run it to get out of the slip and I set sail ASAP to kill the noise.

My personal decision is based on the following factors:
-Simplicity of maint
-Simplicity of operation (one begets the other)
-Noise/environmental
-Definition of use (i don't need it to make way)
-My wife has to be able to operate and maintain it.

For me - Price is less of a factor becasue initial costs are only a one time hit.
The recurring costs of ops & maint are the real kicker (they sneak up on you and kick you in the keister when your not looking!). Recurring costs can well exceed the price you might save on a "great deal" you may find if your not careful.

Good Luck
Shack

[SimonV]

I have just read the uk is banning 2 strokes to come into line xwith the EU.

2 strokes are still tops as far as simplicity. they are considerably lighter for a given hp, can be put in a locker without the worry of oil leakege or fouling the plug.

this thing about the envioroment? how far do you travel in the dingy 300-400 yrds max .

fight for your rights, a small 2 stroke is an advantave in wieght by an average of 30%. thats a big differece when pulling it up on to the pushpit.

[SteveCox]

I have a san Juan 7.7 with a 8hp 2 stroke. If I were re-powering I would buy a 4 stroke mainly because of one issue, NOISE! I hate the buzzing of the 2 and would dearly love a 4 because of it. We wind up motoring quite a bit here in S. Puget Sound and the noise really bugs me after a while. If it was dinghy power that is another story but for main power for a sailboat get a 4 stroke.