Favourite workhorse engine (30 to 50 HP)

Channel Ribs · 19 October 2008, 09:21

What would be your choice to put on a boat that is going to be doing sub planing speeds all day every day for months on end?

Initial cost needs to be low.
Fuel economy is not too important.
Reliability and access to parts is the big one.

In the old days I would have gone for a 30HP Tohatsu two-stroke.

Nos4r2 · 19 October 2008, 10:18

What would you call low initial cost?

Channel Ribs · 19 October 2008, 10:52

Quote:

Originally Posted by Nos4r2

What would you call low initial cost?

Depending on the horses I guess, but sub 4k for the top end of the power range.

One option suggested was a pair of 15HP four strokes, ok so long as the block is one of the bigger ones.

Nos4r2 · 19 October 2008, 11:13

I'd be looking for an ex leisure 50hp 4 stroke Honda. It'd last forever at displacement speeds.

ruddles · 19 October 2008, 11:17

Tohatsu.
End of chat

Poly · 19 October 2008, 11:34

Quote:

Originally Posted by malthouse

One option suggested was a pair of 15HP four strokes, ok so long as the block is one of the bigger ones.

? twin engines only about 70% efficient as a single with the combined HP, so a pair of 15s will give you little over the equivalent of a single 20HP. Then it will probably weigh more, and have double the maintainence costs etc. Thats also assuming you have space for them on the transom. Unless you need the backup of having twins, or the extra manouverability then I don't think it is sensible.

Might make a difference what its for. E.g. if it for a workboat shunting yachts round a harbour that needs lots of grunt but not much top speed or if its for a safety boat that will spend its life ticking over but occassionally might need to go flat out.

Is it being used commercially? - because then I think who offers the best commercial warranty will matter. What sort of hours will it do? An ETEC with 300 hour service intervals might be attractive compared to a 4-str with 100 hours.

In terms of cost I'm not sure if buying new that there is a huge amount in it (~10% of value), and your ability to get servicing/help if needed is probably more important for a boat that is needed every day.

Channel Ribs · 19 October 2008, 11:58

Used is out, unless it has a certified history or is a dealer recon.

The boat will end up doing lots of hours at low RPM, very rarely ever needing any speed at all.

The extra maneuverability of twins would be nice and being able to take one off for service/repair without leaving the boat high and dry would be good too.

ian parkes · 19 October 2008, 21:41

Twin honda 20's under 50 kg very smooth and quiet lots of torque and frugal on juice .

Turbodiesel · 23 October 2008, 16:59

How about Mercury Seapro 40hp, 2 stroke? simple and realiable.

BassBoy · 23 October 2008, 17:18

Should we call you MainBrayce!?

Easy.........suzi 4stroke

Channel Ribs · 23 October 2008, 17:21

Quote:

Originally Posted by BassBoy

Should we call you MainBrayce!?

No! Most certainly not.

It is for a safety boat, but one that does not need to respond with speed. More of a self propelled platform really.

Quote:

Originally Posted by BassBoy

Easy.........suzi 4stroke

Don't get me wrong, the Snoozukis are a nicely designed engine, but the two part cowl that covers some of the more useful service items is a bit of off putting feature to my mind.

Channel Ribs · 23 October 2008, 17:24

Quote:

Originally Posted by Turbodiesel

How about Mercury Seapro 40hp, 2 stroke? simple and realiable.

Are they available new to commercial users?

BassBoy · 23 October 2008, 17:26

Fair point on Snoozi.

Careful you don't give anyone a lift off the moorings or you might find your boat hung off the wall and stabbed!!!!!!!!!!!!

BB

Channel Ribs · 23 October 2008, 17:29

Quote:

Originally Posted by BassBoy

Careful you don't give anyone a lift off the moorings or you might find your boat hung off the wall and stabbed!!!!!!!!!!!!

I did give some nice French chaps a tow the other afternoon, does that mean the dinghy is in even more danger now? Also, is it the boat or me that gets knifed??

BassBoy · 23 October 2008, 18:47

I think it was just the boats! You might ask the ****trouts for the real answer, but beware the Horses Head in the Bed!

Doug Stormforce · 24 October 2008, 17:05

Malthouse

A bit more info would be useful.

On what you have told us I would say no to the twin idea

I assume it’s a small boat so should be manoeuvrable enough with a 40 or 50 anyway.
the benefit of 1 engine failing and having a back up is some what negated if you are only operating in the harbour.
The benefit of 2 separate fuel systems is also some what negated for the same reason
Twin 20s are going to way more than a single 40 I suspect
Twin 20s are going to underperforms a single 40
Although you can service 1 at a time this means your boat will not be able to do its job properly for twice as long, it will also increase total service bill

In summary you don’t really need the benefits of twin engines but will suffer the disadvantages.

As already said Honda 4 strokes of that size are quite happy doing extensive periods of slow stuff and Yams are not generally so fond of this sort of treatment. I've got a mariner 15 on a rigiflex that does a lot of safety boat stuff in the river, its 3 months old and does seem to appreciate a few blasts every day if we do lots of slow stuff.