Honda 50hp or ETEC 50hp???

Squish · 03 April 2008, 00:59

Hi,

I'm new to the site, though I've been researching here for quite awhile. I'm looking at my first RIB, it's a 4.5m Polaris aluminum hull, and it currently has a 2002 - 50hp Honda 4 stroke motor on it.

I plan on using this RIB fully loaded most of the time, often with 3-4 people and either dive gear or kite surfing and camping gear. Due to $$$, storage and access issues with the areas that I'm heading to, it isn't realistic for me to buy a larger hull at this time, though I'd like to in a few years from now. But, after taking the boat for a sea trial, the motor felt a little sluggish to me, topping out at 34mph with 2 people in it (14" prop) and cruising at 24mph at 65% throttle and I'm sure that speed would drop pretty fast with a 13" prop and some gear.

So my question is, do you think that I'll notice a performance difference by upgrading to a new 50hp Etec. (I can sell the Honda now, before I use it too heavily and it'll only cost about $2000 to repower) I understand the Honda's HP is measured at the crank, and generally the Etec's perform more like a higher HP engine. The weight of the two motors is within 15kg of each other. The other option is to go to a 60hp Etec, though this is over the boats rating, even though it is the same weight as a 50hp. The comparable Zodiac is rated for a 70hp and the Polaris' tube are the same diameter, so I'm thinking that should be ok.

So what does everyone think? Any opinions or suggestions are appreciated.

Thanks.

prairie tuber · 03 April 2008, 02:29

Ask Guy over at Polaris if the 60 ETEC is OK or if he can bolster the transom with an extra aluminum gusset or 2 to ensure that it is. IMO, the 40 and 50 hp ETECs are pretty heavy for their power output.

Squish · 03 April 2008, 02:45

I forgot to say, I spoke to Polaris, and he said that the stock hull and transom can handle more power, it is Transport Canada that sets the ratings as low as they are. Biggest issue they figured that I would have to deal with is my insurance, if there was ever an injury claim.

Douglas · 03 April 2008, 18:34

I went from a 50hp Merc to an 50hp Etec. The dealer told me it would be loads better. Lighter, more economic, quieter etc. Anyway it was quieter but as to the rest, not impressed. Much heavier so the boat 13ft dory could not carry the weight! The Honda is lighter and in my opinion a much better engine. I think that the bigger Etecs might make sense but there are better 4 strokes at this power range.

If you must have the Etec get the 60hp, the 40,50 and 60 are the same engine.

Doug

ribfan · 03 April 2008, 23:45

Hi, In the end, 50 hp is 50 hp. All new engines are rated at the prop, so, to be nice, the dealer is pulling your leg in attempting to separate you from your money. 10% -15% increase in power will get you only 3-4 kts additional speed if you are lucky. The best solution would be to determine the max hp the boat can take, see if it is enough to make a difference. If you could upgrade to say, 70 hp or so, it might be worth the upgrade, if not, enjoy the rig for what it is. The honda is a great engine.

Bill

www.eclecticwonders.com uncommon art

yorfuoj · 08 April 2008, 08:34

with the same cubic-inches, a 2 stroke engine has more torque than a 4 stroke, so it much more efficient to plane or pull a skier.

The motor weight is another parameter, and it becomes more and more important on a short hull like your Polaris. To compensate for the Etec overweight, you will need a shorter prop pitch and fins, even if it has more power available at low rpm.

With this kind of hull and length, I would choose the lightest engine, a 50HP Tohatsu - the best being the old version with carbs, weighting 80kg in the trim version. But even le LPDI version would make a big difference with the Honda 50 - and a huge with the Etec

Squish · 09 April 2008, 04:38

Quote:

Originally Posted by yorfuoj

But even le LPDI version would make a big difference with the Honda 50 - and a huge with the Etec

I'm sorry, I dont understand what you mean here. What is LPDI? I checked out Tohatsu's website, and I didn't see any reference to LPDI there.

Thanks.

prairie tuber · 09 April 2008, 04:48

I believe LPDI stands for low pressure fuel injection - which is the system that the new Tohatsu/Nissan TLDI engines use. This system does require a battery to run, so there goes any weight advantage over an ETEC rope start.

Channel Ribs · 09 April 2008, 16:06

Quote:

Originally Posted by prairie tuber

... there goes any weight advantage over an ETEC rope start.

Unless you use a small battery.

http://shop.malthouse-marine.com/ind...=206&parent=20