Two cylinder versus Three cylinder

[~Nickolas~]

Hello,
My first post to this particular section. I own a 1992 Evinrude 60HP two stroke and it is on a 17' sea nymph Tournament aluminum Bass boat. I got the boat off ebay and it turned out to be about 20 miles up the road from where I live and it worked out great. The engine is very strong and the boat's best speed to date is around 53MPH.

I have installed Boyesen power reeds and fine tuned the engine with service manual adjustments and the engine always fires right up and has never let me down. Compression test results were 120-115-120 which is acceptable. Anyway I was wondering why Evinrude went back and fourth between two cylinder and three cylinder engines of the same HP rating. I read the test reports of the new two cylinder e-tech's and they don't compare to my three cylinder model.

I also usually have a half tank of gas along with a second person along with gear and still get to 50 with ease. Several of those test boats were at 30-35 MPH or a little more. I wonder if their would be any more power and or speed if the e-tech's were three cylinder engines? Do they make them two cylinder's to save on costs or is there another reason? They also boast about how quiet they are and the fuel economy is so much better. I can see where fuel economy is a concern but for engine noise I don't see what the issue is.

If your moving along on the water cruising at full speed or near it it's not like you are going to be in a deep conversation anyway so what does it matter. I personally like hearing the sweet tune ( noise ) made by my engine. To me it is music to my ears. Different engines have different sounds and some are fairly quiet and some really bark when you get down on the throttle. I guess it's all a matter of personal preference and to each their own but there are some engines that really have a sweet sound to them as you get down on them.

Maybe a family boat or something folks would want a quiet engine on a pontoon or what ever it may be. I love the sound of an outboard and especially at WOT. Anyway back to the issue of two versus three cylinder's I guess today it's all cost related. I haven't been in a boat with the same 60HP and with two cylinders so I don't know what the difference would be. Any thoughts on the subject?

Nick

 

[henrye718]

Re: Two cylinder versus Three cylinder

Is it a open empty hull? I have owned two boats 17' with 60hp 3 cylinder outboards. A johnson and a merc, neither went faster that 30mph. How are your reading your speed also?

 

[Knightgang]

Re: Two cylinder versus Three cylinder

It is an aluminum Bass Boat. Light, close to flat bottom.

 

[~Nickolas~]

Re: Two cylinder versus Three cylinder

Just like a jon-boat but with a console and compartments like any other bass boat has. Open hull i guess you can call it. I use the Lowrance unit for speed with the paddle wheel on the back side of the boat which is an electronic unit with digital speed. I also have a GPS to use. It is very accurate and we are cruising along with eyes watering from the wind. I have to keep sun glasses on to keep my eyes from watering at full speed. I also experimented with different props and the 19 pitch got me the fastest speed. The 17 pitch stainless really digs in and makes the boat launch like a rocket but my favorite prop is the composite Comprop four blade that makes the boat cruise soooo much better. Best speed with this prop is 50MPH but it really makes the boat much better all around.

With the three blade props you could feel engine vibration at around 5000RPM and I backed off the throttle because it didn't feel good. Now with this four blade I get it up to 5400-5500 and the engine runs soooo smooth its a night and day difference and I now use it for my main prop because of the smoothness in the engine and also the boat handles much better. This was a huge improvement in ride and handling not to mention the smoothness of the engine at WOT. Now I want to get a stainless four blade prop just for safe measure incase I hit any under water obstacles. This is a pic after I bought it. I have since fixed the skeg with a new one along with other upgrades.

 

[Bifflefan]

Re: Two cylinder versus Three cylinder

Now I want to get a stainless four blade prop just for safe measure incase I hit any under water obstacles.

Id stay with the composite for hitting stuff as it will break and not damage the lower unit. An SS is very unforgiving. Is the one you have one that you can change the blades on? If so then take a set of spares and your golden.

 

[~Nickolas~]

Re: Two cylinder versus Three cylinder

Nah can't change the blades on a Comprop but I still like it. The stainless 3 blade prop I got is the best for performance as it is like a drag boat taking off. It really launches the boat hard and gets up to speed very quickly. I'll take the smoothness of the 4 blade though because the boat just rides a lot better. No more porpoising and bouncing around but just cruising along like it should and the engine is singing a nice tune. I tell ya the smoothness of the engine from that prop change was drastic. I can't get over how smooth the engine runs at 5500RPM now. The 3 blade prop vibration made me back off of it and not get up to WOT. This composite 4 blade is sweet. I want to get a 17 pitch composite 4 blade now so I can get right to the 6000 RPM limit.

I'm not worried about engine wear and such as other folks are. I'll just rebuild it when the time comes as long as it doesnt blow for some reason or another. Love the sound of WOT humming along. Another thing is I use PRI-G for an additive and ethanol treatment and it is great stuff. No worries of water or phase seperation anymore with this chemical and so far so good with performance. With good quality gas and Boyesen reeds the throttle response is excellent. I'm impressed with the power this engine makes and its plenty fast for me for the moment. My goal however is to one day have a 200-225 on the back of another boat for even more full throttle blasts.

Nick