suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

[superduperest]

Hi, i have a 3.1meter RIB and its rated to a max of 15hp, what i need to know before buying one is whether a 2stroke or a 4stroke is better for this boat/me. would there be much difference in performance once a few people are on board? I know my brother would be interested in towing a ringo or some other water toy. Any advice would be appreciated, thanks Chris

 

[Sea Rider]

Re: suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

If possible go for a 2 strokes engine, weights about 10 less Kg than the 4 strokes version, less weight at transom and much more friendly to carry.

Happy Boating

 

[henryfreston]

Re: suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

You have to weigh the pros and cons for you.
4 strokes are generally newer engines with warranty so you are covered- you can't buy new 2 strokes for leisure use
4 strokes consume Much less fuel and you don't have to mix the fuel an oil, just straight in with unleaded
4 strokes are very quiet and smooth engines so perfect for lazy days fishing and trolling
4 strokes are easy to start
2 strokes have a better power to weight ration
2 strokes are lighter
2 strokes are generally easier to fix if they go wrong because they are more simple.

there are a few pros of the two there. Only you can decide.

 

[superduperest]

Re: suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

Ok thanks guys, do you think the 4stroke would have the grunt to pull an adult in a little ringo/water toy? I do like the idea of less fuel costs. Thanks again

 

[henryfreston]

Re: suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

well they do have more torque, I would think so, especially on a 3.1m rib. Give it a go, test some. I personally prefer 4 strokes and that is what I would recommend to anyone. I think two strokes look and sound crap. Most of them anyway, because the vast majority are over 10 years old and have sometimes lost a bit of there power, 4 strokes don't lose power. It would definitely pull a ringo, just slightly slower than a two stroke. But then if you only have to pay a ?10 to go out all day you don't mind. Remember for two strokes you have to buy the oil also which is expensive.

 

[fbpooler]

Re: suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

Either design will provide the rated horsepower, but unless you are a mechanic be careful of some of the comparisons people give.

If you do not mind the weight, the four stroke is a very nice engine. Be aware however that repairs require much more than a two stroke due to the additional systems required to make them function, and there are more moving parts to wear. In the 15 HP class, the difference in gas mileage between the two is not as much of a problem as with larger engines. Keeping a two stroke in new condition is much easier and less expensive than with the four stroke. A marine dealer who is one of the best outboard mechanics I know told me when four strokes became popular that the owners would be very surprised when the engines required repairs. In addition to the work required to repair a two stroke they would have to pay for additional repairs due to the induction systems and other parts.

The two strokes we have owned only required one or two pulls on the starter to start. As they have fewer cubic inches for the horsepower, compression releases are not required on the smaller blocks.

For portability, the two stroke is less of a problem as it does not have an oil sump to be concerned with. As you are looking at a RIB rather than a SIB, you may not have occasion to transport the engine lying on its side. If you trailer the rig, the four stroke would serve you well.

You will find that a two stroke may be problematic to find for sale, but don't overlook one if it becomes available. What is best for you is your decision.

Remember that the four stroke outboard came of age due to environmental decisions, not improvements in performance.

 

[2manband]

Re: suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

All 15hp ratings are not created equal.

Some time around 1983 the rating point changed from the powerhead to the propeller. Because 4-strokes became popular after this changeover, they're almost all rated at the propellor. In the "rate HP at the powerhead" era, 2-strokes were the most common.

So old motors of a given rating are generally 10 or 20% less powerful than new ones, even if they're in perfect condition.

If everything you're considering is newer than 1985 or so, then all of the ratings were taken at the prop, and you can make an apples to apples comparison.

 

[superduperest]

Re: suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

Ideal, and thanks for everybodys advice. I decided to go with a 15hp 4stroke in the end(just in time for the clocks to go back and the days to get short and cold,brilliant!). Any idea of what kind of speed I should be expecting to get out of it? Quite looking forward to taking it out this weekend

 

[mj05]

Re: suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

Superduperest, I'm looking forward to hearing how things went on the water! I too am wanting a boat for next season and am also hoping to pull a tube in addition to a little fishing. Let us know how she did!

 

[superduperest]

Re: suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

Superduperest, I'm looking forward to hearing how things went on the water! I too am wanting a boat for next season and am also hoping to pull a tube in addition to a little fishing. Let us know how she did!

Well my brother and I took my RIB out on Saturday and it was bloody good fun, the 4stroke 15hp does about 25mph with 2 people on board. It is bloody heavy to carry around though, i only had to carry it from the house to the car (about 50meters) and that was more than enough and even then i couldnt lift it into the car and just had to push it over and then slide it in. I use a trailer but if you would be physically moving it each time then you will need a hand. We hope to tow a little ringo or something similar this weekend,weather depending,so I will let you know how that goes. All said and done,great fun

 

[fbpooler]

Re: suzumar 3.1m RIB, 15hp 2stroke or 15hp 4stroke?

You are handling 40% more weight than the two stroke based on Yamaha engines, so it would be heavy. 111 lbs vs 79 lbs dry, so there is more to handle. It will give you good service though, so enjoy it.