Motor Selection - 4-Stroke vs. Optimax

[JonnyBfromHutch]

Having fun thinking about a new rig, and have really had my sights set on a 4-stroke. However, the local Merc dealer is really pushing the OptiMax vs. the 4-stroke, and has got me thinking again... I know this is a much-discussed topic, but for a fishing-only rig is there any reason to NOT buy a 4-stroke these days? I appreciate any input - thanks!

[camdu7]

I think it depends on the size. Samller than 90/115 I would lean 4 st. Larger I would go DI 2st. I own a 150 opti and love it. Lots of power, no smoke, great on gas. smooth and easy starting. The only thing the four stroke has on it is quieter at idle. The opti is not loud but not quiet like a 4 st. I don't care cause I have a kicker. Another big plus of the opti is my 150 and kicker weigh about what a 150 4 stroke alone weighs, plus you get the power of a 2 stroke. This is just my opinion and observations.

[250XB]

On the bigger engines the optimax is faster get better fuel economy and weigh less

[Scott K]

I have a 115 4-stroke Yamaha, I love this motor, a friend has the 150 Optimax he has had several problems with it, nothing big but just problems, slow idle, stalling out, not starting very easy. I have had zero problems with the 4 stroke. I am not saying that this is typical, he is the only opti owner I know, and not happy either!

[Sutty]

I have a 135 opti. I like it but will like it more when I have a kicker...

Gas isn't a deciding factor since they are both good. It really comes down to noise, weight, and maintenance. No oil change on the opti.

On my boat I thought a four stroke was going to be too heavy, especially since either way I went I was going to get a 4 stroke kicker as well.

[PerchJerker]

 Originally Posted By: camdu7

I think it depends on the size. Samller than 90/115 I would lean 4 st. Larger I would go DI 2st.

I agree with this. I am a big fan of DFI motors for power, performance, and fuel econmy when you get to that size of motor. I think the only advantage to a 4-stroke is the quietness unless you're talking about smaller motors (below 90/115). I have a 175 Opti and love it. Good luck with your decision.

[Scoot]

Let me preface this question with this: I am not a tree hugger! However, I think more and more about what I'm doing to the environment...

What about polution and the "cleaness" of the motors? How much difference between the new opti's and 4 strokes?

[PerchJerker]

 Originally Posted By: Scoot

What about polution and the "cleaness" of the motors? How much difference between the new opti's and 4 strokes?

DFI motors like Optis were designed to meet the tougher air and water pollution standards. There is little difference between DFIs and 4-strokes in terms of polution, cleanliness, or fuel consumption. In some cases DFIs like Optis are better than 4-strokes for fuel consumption.

This goes back several years, to the mid '90s if I remember correctly. But .........

Much stricter air emission and water pollution requirements were announced for outboard motors, and manufacturers had several years to get their motors to comply before the tighter regs took effect. The carbed and EFI 2-strokes being produced at that time did not meet the new standards, and it was believed the new standards would basically kill the 2-stroke outboard motor and force everything over to 4-strokes.

A problem was that 4-strokes motors were heavy, slow and lacked power, so some of the motor manufacturers looked for ways to get 2-stroke motors that would meet the pollution standards. DFIs meet that standards because of the way the gas and oil is mixed and burned inside the motor. DFIs are also lighter and more powerful so there were some performance benefits that were gained by staying with a 2-stroke that complied with the emissions regulations.

DFIs and 4-stroke motors have both improved over the years. DFIs fuel consumption has improved to rival or beat 4-stroke fuel consumption, and 4-stroke power and weight has improved so their performance is now a lot closer to 2-strokes than what it once was. Both technologies are good and are clean, it's really personal preference.

It's interesting to note what's happened to some of the motor manufacturers because of the stricter pollution requirements. The OMC Ficht was an early DFI motor that was mostly a failure and pretty much took down OMC. Merc went with the Opti and partnered with Yamaha for 4-strokes, until their price protection fall-out caused the two companies to split. Now Mercs small 4-strokes are Tohatsu amd they have come out with their Verado 4-strokes. Their carbuerated 2-stroke Mariner line can't be found in the U.S. anymore, but I think are still being sold around the world, as are other manufacturer's carbed 2-strokes. Honda has always been 4-stroke only (and expensive) and was a bigger player early in the 4-stroke trend than they are now (that there's more options and competition). Yamaha has their 4-strokes and used to have their 2-stroke HPDI direct injection motors but I believe they are no longer making their DI motors. Lots of changes in the outboard motor industry can be tied back to the stricter pollution regs.

[fishorgolf]

Hey Perchjerker,

optimax 150 2 star carb rating

yamaha 150 4 stroke 3 start carb rating.

Yes the new DFI's are MUCH cleaner than the older 2 strokes but a fact is a fact, they are 2 strokes and still must burn oil for lubrication.

[PerchJerker]

fishorgolf - I believe you are correct, that the 150 Opti has a 2 star CARB rating.

The CARB rating stands for California Air Resources Board. California has stricter air emission standards than the EPA, and the marine industry rates their motors on California's requirements, not the EPA requirements. Any motor that meets or exceeds California's requirements will exceed the EPA's requirements.

But .... the question was how much difference is there between DFIs and 4-strokes, and I don't know the technical answer but the practical answer is there is not much difference. I have read that 4-strokes are better than DFIs in terms of producing fewer hydrocarbons, and that DFIs are better than 4-strokes in producing less carbon monoxide and nitrogen oxide. DFIs burn oil because they are 2-strokes but that oil is counted in their rating. 4-strokes may burn oil, but that is not counted in their rating. Also, after a 4-stroke oil change the used oil needs to be disposed of or recycled.

The 150 Opti is just one example and that motor has a 2 star CARB rating. Over 50% of the Optis (closer to 75% I think) have 3 star ratings. I think all or most E-Tecs also have a 3 star rating.

IMO the bottom line is that DFIs and 4-strokes are clean running motors, very comparable to each other in emissions and fuel consumption and close enough that those factors shouldn't swing your buying decision one way or the other.

[fishorgolf]

Perchjerker,

I agree that DFI's are clean running motors and I would not not buy a DFI because of the carb rating if this is what you want. BUT, there is a much larger difference between a 2 star and a 3 star than you would think.

2 star 20% less emissions that a 1 star.

3 star 65% less emissions than a 1 star.

[cold one sd]

I certainly wouldn't buy an outboard because a dealer was pushing it. Buy what you want to own. I have a 150 4 stroke and love it. Exhaust emissions are nearly the same and so is fuel economy. Normally a 2 stroke is lighter than a 4 stroke, but a lot if not all of the new boats are built to handle the weight of a 4 stroke engine. I have a 4 stroke kicker on my boat also and have no problem with the combination. My wife gets a very bad headache when she inhales 2 stroke exhaust and I have been running I/Os since the early 80s. I wanted to go back to an outboard and was glad when the 4 strokes came out. I would wonder what was in it for my dealer to be pushing the Optimax unless he just prefers them. Last summer we were fishing close to a boat that had an etec on it and we had to leave the area.

[NELS-BELLS]

I have an '06 115 Merc 4 stroke and my father in law has a '05 150 Opti. Neither boat has a kicker or transom tolling motor. Two years ago I borrowed his boat for a week and what I didn't like was the strong exhaust when back trolling and the noise of the Opti. at low RPMs. You can't even tell my 115 is running at low RPMs and mine starts easier than his when its cold. Mine, you just turn the key.

[caseymcq]

 Originally Posted By: PerchJerker

Yamaha has their 4-strokes and used to have their 2-stroke HPDI direct injection motors but I believe they are no longer making their DI motors.

Yamaha still makes HPDI motors, 150 - 300 hp.

[fishorgolf]

Yes 2 stokes tend to be lighter than 4 strokes but not by much anymore

07 150 opti 431lbs

07 150 yamaha 4 stroke 466lbs.

35 extra lbs (plus a little oil) is a small price to pay for the benefits IMO.

[camdu7]

 Originally Posted By: fishorgolf

Yes 2 stokes tend to be lighter than 4 strokes but not by much anymore

07 150 opti 431lbs

07 150 yamaha 4 stroke 466lbs.

35 extra lbs (plus a little oil) is a small price to pay for the benefits IMO.

Is that a 25" Yami, eather way the 150s are close in weight. In the 200 range I think the weight difference is closer to 100 lbs. For me in my boat, I did not see any advantage in the 4st. THe opti was 1500 less, has less maintenance (oil change, valve adjustments), black motor looks great on the black tyee, and has great performance (seen 50 with my 1850tyee). I guess the exhaust bothers some people, but you eather eat HC with the 2st or CO and NOx with the 4st.

[cjac]

In general, both are great motors and have come a long ways!

Collectively, in regards to performance, maintenance (lack of), fuel efficiency, dependability, and environmental impact, both are heads above of what was available 10 or 15 years ago. We've come a long ways.... Merc had to step up to the arrival of Yammys and other over-seas makes several years ago, and did so, and quite well in my opinion, along with the Verado models.

I run a 115 Yammy 4-stroke and love it, but so does my fishing buddy with his Opti. We can go round and round, but the point is, either rig we are in, we're runnin'! Yeah, Perchjerker with his 175 Opti smoked me leaving the dock at Mille Lacs this Fall, but we both were safe, comfortable, and confident in our rides. We both caught fish too!!

It comes down to what you prefer (Ford vs. Chevy debate), what boat dealer you're working thru, and what suits you best in terms of hull make, rigging, location, etc. It also depends on style of fishing, if trolling, running and gunning spots, long hauls to spots, etc.

Honestly, both are quality motors, and with proper care will serve you for years to come.

Back to the initial poster JonnyBfromHutch: Go with the deal you like that fits your fishing style, the dealer you like and the service they'll provide, can't go wrong with those thoughts in mind!

Chris

[Sutty]

I neglected to mention that I ended up deciding on price. I bought my boat and motor separate. I called around and was finding that most motors around a 150 horse were following the 100 a horse rule somewhat closely. I think the exceptions were the Suzuki's which tended to be less. Anyway I ended up finding a good deal on a 135 opti which is why I decided on it. If you are not sold which way you want to go let the market decide!

[fishorgolf]

well said cjac. They both are very good well tested motors that will serve you well for years.