4 stroke info for a 2 stroke guy

[jbo_c]

I’ve always been a classic Evinrude/Johnson guy - pre-1973. Too dependable and easy to work on not to use them for me. But the boat I’m building really calls for a high thrust and there’s not one in my preferred range of dinosaurs.

So I have Four Stroke questions:

Main one is, what kind of fuel consumption should I expect? Clearly less than my dinosaurs, but I can’t find any real info on burn rates. A corollary to that one is how much will it change from one hp to the next? Will a 20 burn double what a 9.9 does? It will on my old two strokes, but I’m thinking it’s maybe not as linear with new FI engines. I could use anything from a 9.9 to 25 or so on my boat. I’m thinking maybe close to a half gallon/hour if I’m running less than 3/4 throttle? Will there be a lot of difference in fuel burn between the bottom and top of that hp range?

How do I find where the breaks are between head weights so I don’t do something like buy a 9.9 to save a little money and weight when a 15 would have given me a little reserve for not much penalty?

Which, if any of the manufacturers will warranty if I do my own installation? Seems I read somewhere that could be an issue. Are there any for which it would be particularly easier than the others?

I’m guessing all the major players are (generally speaking) equally reliable at this point. Is that true?

Is there anything I should look to avoid?

I don’t have any friends to speak of who are into boats or boating, so outside of this group, I’m somewhat at the mercy of the salesperson(and what I can find on the interwebs). So I’d appreciate any and all advice.

I have some time. It will probably be late summer or fall before I need to pull the trigger, but I like to take my time and research and think things through.

Thanks.

Jbo

[bklake]

I can't answer everything with absolute facts but here is my experience with an EFI Suzuki 9.9. It weighs 30ish lbs more than a Johnnyrude 15 2-stroke. That is what my J-14 started with. I usually putter around, mostly no wake speed with a little full power runs for 5-10 minutes. I used about two 5 gallon tanks a summer with the Johnson. Last year, I put a new Suzuki 9.9 on the back. I did the full break in and some extra puttering around. All on one tank from the supplied 3 gallon tank. I still had just under 1 gallon when I filled it. I swear this thing runs on the fumes coming off the tank.

The Suzuki 9.9 15 and 20 are the same motor. They have different computers and different restrictions on the intake. I swapped computers and the intake spacer and now I have 20hp. The stickers on the motor say 9.9 and the serial number is for a 9.9. It would take a deep dive under the cowl to prove otherwise. It was not cheaper to do this, it would have been $100 less to just but the 20hp. I did it so my kids could operate the boat legally and Dad could still have a little fun. This boat could not plane on 9.9. I don't have numbers for the 20hp configuration yet, haven't run it enough. I suspect it is going to use a lot more gas run hard.

I'm a bit of a Suzuki fanboy. Suzuki is one of the very few that will sell you a motor up to 30hp with a remote. Most require remote models to be sold and installed by a dealer. It's up to you whether dealer installation is what you want. I will tell you that it seems easy to slap one on the back but I found the rigging manual online and it is a lot more involved than you would think. Nothing difficult but a few specific steps and measurements.

[OrangeQuest]

I love my 25HP Suzuki, 2023 model. After the break in, I run it at WOT every time I go out for a little while but cruises nicely 4700-5000 rpms. Sips gas and hard to hear it idle. No oil sheen on the water and no gas fumes to smell. I picked Suzuki because it comes with pull start built in, can be pull started without battery even though it has solid state ignition and fuel injection. Also had one of the higher alternator outputs. It comes with a fuel tank, lines, tool kit, all mounting hardware, throttle and shift control when you buy the remote model. I just had to buy the shift and steering cables to the correct length. All connection ends came with the motor. Had it shipped to me and I self-mounted and maintained it, I still have the 5-year warranty intact. Any warranty repairs will need to be done at the dealer. The dealer would have to prove I caused a failure because I did not install the motor correctly, not likely. Most outboards under 30HP can be shipped and installed by consumers without warranty issues because they are considered "portable".

Some bodies of water/areas/regions do not allow the use of 2 cycle engines anymore due to emissions. Mechanical differences are in the valvetrain and crankcases, but all modern outboards will use solid state/electronics and fuel injection to better control fuel mix and emissions. So, working on them is close to the same. Engine repair, the 4 cycle has more moving parts than the 2 cycles but are just as easy to work on, just have to add a few more strokes with the 4 cycles when repairing.

Because of more parts and having oil in the crankcase, the 4 cycle will weigh more than the 2 cycle for equal hp. MPG are normally higher in the 4 cycle engines with smoother and quieter idles too. It is easy to add more gas or top off with a 4 cycle, it can be done at the pump and not mix in a container, then top off or add oil to a reservoir.

[Fuzz]

I too am a fan of the Suzuki motors. If buying a new outboard it must have EFI. They start and run so much better. There is nothing like just toughing the key and having a running motor so quite you have to check to see if it is running. The mileage at idle and midrange will be much better. I am not so sure there is much difference at wide open between the two and four strokes. I replaced an old 200hp BlackMax with a 200hp Suzuki. The biggest difference for me was being able idle for hours on end trolling with no smoke. That old BlackMax only did three things. Make smoke, suck gas, and haul ass

[bklake]

I did have a serious issue with my 9.9 refusing to start at the beginning of the season. Would not fire up with electric start. Tried to pull start it a few times. Check the fuel can. Checked the battery volts. Everything was as it should be. WTF?












Forgot to put the kill switch key in. Fired right up in 1/2 a revolution with that stupid thing in.

[jbo_c]

Suzuki seems to be well represented here. Sounds like they come with the controls(if remote), but no cables. Guessing that also means they don’t come with a wiring harness?

What would they be wired for? RPM, oil(pressure), what else?

Thanks for the responses.

Jbo

[jbo_c]

Kill switch is a classic, for sure. Gotta start with the basics.

I almost called a wrecker for my wife’s car last week because it “wasn’t driving right.” Had phone in hand when I realized one of us had bumped the 4WD button and not noticed. Glad the mechanic didn’t have to point that out to me. LOL

Jbo

[BarraMan]

My loyalties are flexible!

Back in the day I was a Mercury man, then a Suzuki man (both 2 strokes) now I am a hard core 4 stroke Yamaha man - own two of them (40 and 250 hp). In this part of the world most commercial operators have Yamahas!

[bklake]

Suzuki seems to be well represented here. Sounds like they come with the controls(if remote), but no cables. Guessing that also means they don’t come with a wiring harness?

What would they be wired for? RPM, oil(pressure), what else?

Thanks for the responses.

Jbo

Mine came with everything less control cables, steering cable, and a battery. It did include a steering arm. The prop was clearly for sailboat duty so I had to replace that too. Suzuki electrical plugs seem to have been standardized from 9.9 to 350 hp. Get a Suzuki gauge of compatible vintage and it will plug in and work. I'm pretty sure the SMG4 will plug in if you like dropping $500 for a fancy gauge.

Check the spec sheets and buy from a dealer that leaves everything in the box. I seem to recall one or two dealers that stripped out the accessories and tried to sell them as an add on.

I have had good luck with Suzuki but always keep in mind, it's machinery attached to a boat in salt water. It's going to have problems at some point.

[TomW1]

Just my two cents' cables are not included because the length varies by the design of the boat. Some boats will need 12' others may need 18' long cables, depending on the distance from the console to the motor. As far as the wiring harness most motors come with the one needed for the motor and gauge package you select. The dealer will hook you up when he hooks on the motor.

Tom