2 stroke or 4 stroke how can ya tell what you got?

[tywos]

I know this should be obvious but, me and a friend bought a boat.<br />The boat has a 1965 or 66 mercury outboard motor (65 hp). now i see four (4) spark plugs in four (4) cyl's. So i believe it's a 4 stroke eng.<br />my friend say's " well, it has to be a 2 stroke cause we mix the gas and oil" <br />My question is..... which is it?<br /><br />Any info on this matter would be great...thx

 

[andrewkafp]

Re: 2 stroke or 4 stroke how can ya tell what you got?

If its a 1965 it would be a 2 stroke as 4 strokes have only recently been introduced.<br />The main difference is not the number of plugs, but the fact that there are no valves or camshaft.<br />and generally, the carbs are at one end and the plugs at the other. You are right.. if you pre-mix fuel, it will be a 2 stroke as they have no sump or oil bath and are lubricated by the oil mix that is inducted into the crankcase.<br />Post the serial number and we can tell you the year and the mix ratio.<br />This is a 1969 it would most likely look similar<br /> http://i4.ebayimg.com/01/i/01/40/65/99_1.JPG

 

[Clams Canino]

Re: 2 stroke or 4 stroke how can ya tell what you got?

It's a two cycle(stroke), four CYLINDER engine.<br /><br />The mix ratio is 50/1. <br /><br />-W

 

[LubeDude]

Re: 2 stroke or 4 stroke how can ya tell what you got?

Wow, all of us arnt Rocket Scientists!!<br /><br />I really do not mean to make anyone feel bad, quite the oposite! Sometimes we need a question like this to let us know that some people really do not know!<br /><br />I took a guy for a ride one time up into the woods to show him around the area after he moved here! I had been hunting and had a couple of 270 shells in the console of my P/U! He picked one up and asked me how much of it actually went out the barrel of the gun, I almost ran off the road!<br /><br />Welcome to the board, please keep posting and do not take what I said as a slam, It wasnt ment to be! We all will help with anything you can come up with, and do it politly!

 

[tywos]

Re: 2 stroke or 4 stroke how can ya tell what you got?

thanks alot for clearing this up between me and my friend.<br />we are both just 18 yrs old, and this is our first boat.We had to fix it up some and replace alot of the cosmetic stuff. but other than that it's a nice beginner's boat. again thx

 

[rickdb1boat]

Re: 2 stroke or 4 stroke how can ya tell what you got?

Good Motor!! Had a 67' 650 and ran the h##l out of it... Sometimes hard to start, though. Nature of the beast. Take care of it and you will have a reliable motor for a long time...<br /><br />And get a Manual for sure. It will give you all the maintenence you need to do. Bottom left of this page has them. Get the Seloc for beginners!