Which Portable Outboard?

[bluefin]

In the next few weeks i will be buying a 385 quintrex explorer.
The BIG question is what to put on it?

I need to be able to lift it on and off so have a 50 kg weight limit.

The contenders are: 20 hp 4 stroke Honda
or

25 hp 2 stroke Yamaha

Both are around 50 kg

How much quieter is the 4 stroke, is it worth dropping 5 hp for it?


Thanks

Howard.

[Bear]

After having the 4 stroke I won't be going back to a 2. Noice, no more mixing fuel etc. That's the difference to me.

[Peter N]

Bluefin,

I just bought a 420 Dory and put a 30 hp Yamaha CV 2 stroke on it. A guy that I spoke to while shopping around said that Yamaha had a glut of 30hp CV motors so they were only $30 more than the 25's. I think he said $3300 for 25 and $3330 for the 30. The only down side of this motor will be the weight. It may be too heavy to lift at around 58kg. This is 5 kg more than the 25.

I have mine bolted to the boat so the lifting isn't an issue, but it may be worth some investigation. $30 for 5 extra horses ain't too bad. And by the way, it really flies along.

Yes the 4 strokes are a lot quieter, but does the better fuel economy and noise reduction justify the extra cost of buying and servicing the motor?? There have been some threads on this in the past - might be worth the search.

Personally I would go with the 2 stroke and get as many hp as possible. Apparently hearing is over rated and oil is good for the skin anyway.

Hope this is of some help.

All the best for the new boat.

Peter.

[durko]

four stroke 20,
your explorer will fly with that.
but i would check out yammies or suzuki's you may be able to get a 25 without much weight difference

[madsurfe]

Hi Howard

so your getting your hands on an explorer eh! nice little hull... for sure. There were a couple getting around in Perth when the Breaming scene took off and they performed admiraly with a Yamaha CV 30 hanging off the back.

You say that you need to take the motor off, how often? will it be a common occurence to allow for trailering? storage?

It's not much fun having to lift off a motor by yourself and they'll all be cumbersome regardless of the brand. Although saving a few kilo's of weight can make all the difference. Mim and I have the CV 30 and it's a pain getting it on and off.

[Bream Addict]

mate ive been doing alot of research on this lately,and although i wasnt factoring in lifting the engine,i would always go the 4strk nice and quiet,fuel economy and many other advantages.lets face it,its a breaming boat,ur never going to be outrunning storms and such so,imo losing 5hp for quietmess and cleanliness is the better option,jmo.

[madsurfe]

You should find these stats useful:

Honda BF20 4 Stroke
BF15 & BF20 are 2 cyl 350cc and same weight running a 10p prop Gear Ratio 2.08, single carby

(S-Type): 46.5kg (L-Type): 49.5kg (X-Type): 52kg


Yamaha CV 25(BMHS/L) & 30(HMHS/L) 2 Stroke are the same engine 2 cyl 496cc and proven to be bullet proof with low maintenance cost. A number of Breamers have owned one or more.

They are single carby and run a 12p prop Gear Ratio 2.08 weighing in at 54.5kg. Max fuel usage 11.5L/H


Yamaha 20(DMHS/L) & 25(NMHS/L) 2 Stroke are the same engine 2 cyl 395cc weighing in the range 48-49.5kg. They run 2 carbies and a 11.25p prop,Gear Ratio 2.08. Max fuel usage 11-12L/H

I couldn't find WOT fuel usage for the Honda BF15/20 but the equivalent Yamaha F15AMHL runs at 5.3L/H weighing 47kg. Do not compare fuel figures for the 15/20hp motors against the 25/30 motors cos' the 25/30 have more cubes. eg: the CV25 has 42% greater cubic capacity. A typical relationship between 4 & 2 stroke fuel usage is to look at similar motors.

Looking at the 4 stroke Yamaha F25AETL you will see that at WOT it uses 9.2L/H which is not that much different to my CV30 using 11.5L/H. I actually get better fuel figures than that but it's another story.

[madsurfe]

I imagine that some of you are wondering why I raised all this info, it's important if you want to set up a boat that works well. Many people get confused on these more technical points.

so Howard are you going to kit the hull out with Decks, livewells or a leccy? Will you consider doing it in the future? If so then you don't want to be up for a new motor purchase.

Four stroke 25/30hp outboards are out of question because they are getting around 70+ kg's in weight. Not really something that you want to be pulling off on a regular basis.

If you load the boat up then the Honda BF20 will be a pretty average choice. It lacks the torque of the other motors. This is easily seen by the pitch of the prop. The Honda runs a 10p 4 blade prop to make up for the lack of grunt. It will also limit top speed. It's just like putting smaller wheels (diameter) on your car which will improve acceleration but knock off some top end. The only advantage is the quietness at idle and marginally at WOT if engines of the same size are compared. The initial purchase price of the 4 stroke is greater than the 2 stroke but in reality can you recover the extra dollars in fuel savings? We currently spend $10-12 per month more on fuel to run the 2 stroke.

I have paid close attention to these details over the past 28 months of fishing and the boat is on the water every week... weather permitting, the rain is pelting down as I type.

I hope this helps you make a good decision

[peter bear]

howard this boating mob in QLD have done all the testing of small motors on a variety on tinnies and they have come down to 1 motor thay use and it is the 20 hp honda.
the sell fully set tinnies after a few years of ownership and hundreds of people ring day and night trying to buy them.
i bias to them as i;m a subscriber.
http://www.seamedia.com.au/pub/index.php

[bluefin]

Thanks everyone, there is no clear cut answer,is there!

The boat will also be transported on a campervan, hence the need to be portable. The motor will go on a swinging arm on the back of the camper , like the tyres on some 4wd's.
The boat weight is also important, so no casting decks ect, and it will be upside down no the camper! Will be loaded with tons of fishing gear, naturally, and live bait tank, 100 amp hour battery, esky full of fish, hopefully!

I'm leaning towards the 2 stroke, can lay it on its side in the back of the patrol if needed for security, and the extra power.

Boat is rated to 25 hp so 30 will create insurance issues!

The yammy dealer, in trying to sway my opinion, said that honda had corrosion issues and no resale value! Haven't heard that one before!

Howard.

[madsurfe]

Hi Howard

it's good that you could explain how the boat is being used. The choice in my mind is clearer for these reasons:

Portability is the most important issue and to maximise power against weight. It is not easy chucking 48-50kg around and not recommended to do it alone. It is good that you have an arm to lift/support the motor. I really find that weight is the biggest issue and thus would lean towards the 2 stroke because you'll get more power per kilo.

The 385 Explorer will perform well with a 15hp hanging off the back because you're not going to fit the boat out for full on Breaming. Geez.... we had a 15hp motor and struggled to plane once the floors and leccy went in along with a couple of people.

I've got to fly off to the Doc's to get my stitches out so i'll finish my rant soon....

[madsurfe]

Hi Howard

your new toy as a basic hull will absolutely belt along... with 25 ponies on the back you just may see 25 knots max speed.

The advantage of the Yamaha 2 strokes is running pre mix with Yamalube at 100:1. They are not smelly smoking motors at that ratio and quite economical on oil usage at 100mls per 10 litres of fuel, buy the little Yamalube measuring bottle with the oil and measuring is real simple for the premix. As you said it is also an advantage to lay the motor down if you need, certainly not possible with a 4 stroke.

The Yamaha 20(DMHS/L) & 25(NMHS/L) run 2 carbies and are smoother at idle than a 2 cyl motor running a single carby. You can save 12 kg's of weight by going to a 15hp 2 stroke or maybe consider the 18hp Tohatsu that weighs 37kg. David V has a Tohatsu 30 and it performs very well.

I'm not sure wether your restricted on engine choice due to dealer/s in your area but a dealer coming across with a statement about corrosion prob's is a bit lame as all the manufacturers use similar coatings and methods to protect their motors.

As Peter said have a look at Seamedia and you can look at the 1st page preview of the 15/20hp Honda in acrobat file. It confirms the issue of weight in portable usage. 'Link below'

Honda Test

I actually got some interesting reads on all manner of boating bits and mods whilst browsing Seamedia. Maybe i'll have to subscribe. Thanks to Peter for the link, well worthwhile.

[bluefin]

Thanks JP.

it is also an advantage to lay the motor down if you need, certainly not possible with a 4 stroke.

This is looming as a big factor!

I am going to have a look at both motors next week and see how easy/hard they are to deal with.

I have a wife and 2 teenagers to carry in the boat, quite a load!
not all the time, but it's nice to have the power when you need it!

The yammy seems to be the lightest in it's class,and the only one to run twin carbs.

Quintrex dealers seem to only have Mercs or Yamaha. There are some interesting salesmen around!!!!!!!

Howard

[Bream Addict]

slightly off the topic, does anyone know,if all run under the same conditions,which 25hp,2strk outboard would produce the least fumes?

[Craig]

Howard

At the risk of stating the obvious - when attaching the motor to your boat don't just rely on the screw/clamps, they may vibrate a bit and become loose and the next thing you know your engine has dropped off the back!

It does and has happened; I will not disclose to whom on this site as I don't wish to embarrass them.

Have a lanyard or something to attach to the motor so it cannot come adrift even if the clamps loosen up.