noise difference? 2 stroke vs 4 stroke???

really how much difference is there between the two? Is it that noticeable? same year engines 2006

Re: noise difference? 2 stroke vs 4 stroke???

My 2001 Suzuki DF70 4 stroke was so quiet at idle that all I heard was the telltale squirting into the water. The quietest 2 stroke I ever had was my beloved Johnson JW-13 3 HP.

In general I find the 4 strokes that I see much quieter than the 2 strokes.

Re: noise difference? 2 stroke vs 4 stroke???

4 strokes are a lot quieter IMO.

Re: noise difference? 2 stroke vs 4 stroke???

We Just sold a Suzuki DF30 four stroke. During the water test, at full throttle, we could comfortably talk to each other in the boat. At idle, as mentioned above , almost all you could hear was the pisser squirting into the water.

Re: noise difference? 2 stroke vs 4 stroke???

Agreed the 4 cycle motors are more quiet. The question is why? I would think it is based upon the design of the exhaust passages, rather than the number of cycles.

Anyone know for sure?

Re: noise difference? 2 stroke vs 4 stroke???

Well, For one thing, you don't have multiple sets of reeds honking like a saxophone!

Re: noise difference? 2 stroke vs 4 stroke???

I bet it also has a lot to do with the fact that two strokes use a tuned exhaust to help pull the exhaust out and hold the intake charge in the cylinder. I would imagine because of those design factors they tend to be louder than what ever type of mufflers/baffles are in the 4strokes exhaust.

Re: noise difference? 2 stroke vs 4 stroke???

You are all forgetting that a two stroke fires all cylinders every revolution. A four stroke fires each cylinder every other revolution. If you really want to analyze this, go to the Performance Test section of the Yamaha web site. Pick any two stroke and the equivalent four stroke. Look at the test reports for the those engines on the same boat. Note that the test reports have dB ratings at the various engine rpms. Now look very carefully at the db ratings at the speed and rpm numbers. Generally the 4-stroke will be a bit quieter but you need to pay attention to the SPEED at which those numbers are taken. A two stroke will almost always be pushing the boat faster than a four stroke at the same rpms. So when the 4-stroke has topped out, look at the corresponding two stroke speed. You will see engine rpm is lower and the noise numbers are quite close. The other aspect about noise is that the 4-stroke makes a different noise than a two stroke and it is that difference, not the number, that people find more pleasing to the ear. And while we are on the topic of speed and rpm, note that the fuel economy numbers are much closer that folks realize as well. This is also because the two stroke is pushing the boat faster than a four stroke at the same rpm. While cleaning my desk I ran across tests of the 75 Yammy 4-stroke and a 70 2-stroke on the same boat and other than than at hull speed (off plane) the 2-stroke is so close to the 4-stroke and in most cases better than the four stroke. At 5800 rpm the 4-stroke is getting 4.6 MPG at 35.4 MPH. The 70 2-stroke at 5400 is pushing the boat at 38.5 MPH and is getting 5.07 MPG. The sad part about 4-strokes is that they struggle to get on plane. At 3000 RPM the 2-stroke is at 18 MPH while the 4-stroke is at 11.1. At 4000 the 2-stroke is 5 MPH faster and at 5000 it is 6 MPH faster. The Evinrude E-tec is better in some areas and equal in others to the 70 2-stroke and a bunch better than the 4-stroke. The current batch of 4-strokes and 2-strokes are good motors. Do your research objectively and look at the numbers, and less on what sales people tell you. Finally, it's been awhile, but last time I checked Yamaha doesn't even post dB numbers in their test reports. Gee -- I wonder why? I have both two and four-strokes so I am not biased and the numbers I posted from Yamaha and Alumacraft for the E-tec.

Re: noise difference? 2 stroke vs 4 stroke???

i would put my etec up against any 4 stroke for quiteness.

Re: noise difference? 2 stroke vs 4 stroke???

i have a 1989 115 2 stroke and it is 70-80% quieter than my old tower of power but the 4 strokes are very quiet.

Re: noise difference? 2 stroke vs 4 stroke???

When you ask about the noise of a 2-stroke, you are obviously used to the old traditional loud smoking engines from years gone by.

The Evinrude E-TEC is the only quiet 2-stroke on the market today and it does not smoke. It compares to the popular 4 strokes in engine sound. No matter which 4-stroke and also with the E-TEC you can carry on a normal conversation at cruising speeds. Idle is super quiet on all of them and at high speeds, the E-TEC has been observed as quieter than a few 4-strokes at the same rpms.

Re: noise difference? 2 stroke vs 4 stroke???

ok so lets bring it back full circle and give more info. I have the opportunity at 2006 15hp johnson 2 stroke. i already have a 2006 honda 4 stroke 8hp. So i wanted to compare these two. I love the etecs and would buy one in a heartbeat over a four stroke but not so much for an etec kicker under 15hp. So i troll with it as a secondary motor and obviously noise in shallow water is a concern for noise weary fish.

I have other concerns too but that might be another thread but 15hp i would pick up ease of maintence, if my main motor died speed for emergencies, also use it in canada for a week a year as main motor, so i would pick a lot of top end speed. Concerns is it might troll my 18ft sea nymph (1600lbs) to fast for walleyes.

pros for honda, quiet, smooth, perfect speed fuel efficient and a charging unit. Cons - storage and transporting sucks, oil filter is i believe terrible to change, it weighs 17 lbs more than the 15hp 2 stroke.

Re: noise difference? 2 stroke vs 4 stroke???

the Honda will be quieter and less smoky than the Johnson carbureted 2-stroke - that is a fact of life

One other con for the Honda is that the carb passages will plug up very quickly with today's fuels unless you continuously use a fuel stabilizer. In extreme cases you may have to buy a new carb as some of the blind passageways cannot be cleaned out sometimes, even using an ultrasonic cleaner.

Re: noise difference? 2 stroke vs 4 stroke???

a traditional carbed 2 stroke is a lot louder than the same power 4 stroke, at least when we are talking multi cylinder engines and not kickers. with a direct injected 2 stroke there is less difference but it still is when we compare it to a modern 4 stroke EFI . and the sound is nicer - my 150 hp V6 DI evinrude had a very nice idle, not to compare with the rumbling of a carbed 2 stroke, but was still significantly louder than a new 135 honda EFI - you hardly hear the engine running when a buddy with his honda manouvers out of the marina. but the sound is also "boring" .

with small one cylinder kickers it tends to be vice versa. i have a 5hp yamaha 2 stroke kicker and it at full power is or at least feels quieter than a 4 stroke 5 hp mercury .

the absolute fail is a honda 2.3 hp air cooled 4 stroke - pretty loud for having no power !