25 HP Outboards Choice

The world's gone crazy.

I have the equivalent 2.5 hp Yamaha which swivels 360 deg, fantastic for holding position in a fast flowing river; tie the kill cord around the OB leg, not your leg......

 

Are you sure?

 

The figures on the Suzuki leanburn are reflected in this months Motorboat owner at http://www.motorboatowner.co.uk/index.php

Test boat: Finnmaster 8 mtr, 3 mtr beam, 3 tons displ. Planing sports boat type hull:
Twin Suzuki 150 leanburn OBs:
3500 revs....15 kts.....51 ltr...... 1.3 mpg
4000 revs....18 kts.....56 ltrs.....1.5 mpg (UK )
4500 revs....29kts......73ltrs.....1.8 mpg
5000 revs.....32. .......93..........1.6 mpg
5500 revs.....35...,......103........1.55 mpg

The high 4500 revs band, the better the 'leanburn ' technology seems to work.

 

Update. We now have the Suzuki 25 complete with electric tilt and initial impressions are good. Smaller block than the Mariner and very quiet, steady idle with sweet gearchange and good flexibilty. It has had a bit of a work out on the Dory and trims well too. Hopefully we will see the lower fuel bills, and this initial performance is maintained.

Currently chopping the transom of another Dory to take a short shaft.....

 

Please keep us updated with some pics...!

And some fuel consumption results too.

 

Thanks Rusty. The real first 'test' will be Easter when it does a week long training course. Then the fuel consumption will be easy to check against two other Mariner 25s', also being used, on one similar hull and a RIB. It is however being used consistently on Saturdays, for training and safety duty every other Sunday. So far, the experienced boat drivers who have used it, report favourably.

Hopefully get some pics and stuff up around Easter.

 

I thought I'd just update as we are getting to the end of the year. We have now put around 500 hours on two four stroke Suzukis' a DF30A (300hrs) and DF25A (current models). Both have been faultless so far, run sweet and from our fuel runs we know they are more economic, though it is hard to quantify exactly as useage is so variable. We've damaged one prop, operator error.... One gripe is it is a bit harder than necessary to set the angle stop on the tilt drive option - you need to remove the bottom ram pin to get to the adjuster stop pin. Still once set correctly you don't really go messing with it again.

Compared to the replaced motors a 25 Hp Mariner (2001 vintage) and a 40Hp Yamaha (2011 vintage) these are much sweeter at idle and the prop and gearing is well chosen driving both a quite heavy boat and a light one well. The data logging from both indicates that most of the time (70-80%) has been spent at idle and under 2k revs, only about 30 mins in the last 100 hours in the last 1000 rpm band ie full throttle. Justified selection so far , so hoping they remain as reliable. Gear change is good - the Yamaha ate gearboxes, well changed every two years, as well as the selector plunger. Considering at least 50+ different drivers so far we shall see if they hold up as well as they have started...

Not a lot of hours maybe, but probably enough to find any teething faults. Can't say the 2009 Mercury 40 EFI has been as well behaved, two coil packs, a power relay and thermostat and that's just one stoppage when at sea only two weeks after a full service.

 

It's hard to quantify any particular model or brand with a couple of examples. For example every manufacture can produce a lemon in a model run, so I find it better to look at the official service bulletins and updates. These show the trends on the vulnerable pieces or possibly poor design elements and engineering approaches. Another good indication about any particular model, is to directly ask the factory tech's that service these puppies and see which parts seem to always need replacement.

 

True PAR, but I work closely with the main local tech guy and have done work for him too. One observation from having 3 Mariner 25s' (near identical) for over 10 years and something like 3,000+ hours each, is they are pretty robust mechanically but the electronics are less so. All 3 have had the alternator magnets disintegrate or start too, fortunately spotted when magnetic debris starts to fly out from the housing.... voltage regulators, starter motors and a few other small things, on the electronic side. You can't blame a fuel pump diaghram for giving up either at some serious hours and years, so not to bad on these 'replaceable' items with hours.

As for the Yam 40, it was a replacement like for like as the previous one (another Yam 40) seemed to be a lemon with the same gearbox 'problems'. Otherwise it was OK, but it does appear to be a less than ideal selector/engagement design. One thing for sure is it does not tolerate less than perfect gear changing over time ie lots of different drivers.

The Mercury 40 has had no problems since purchase (around 1,500 hours) until this random multiple coil pack failure. No obvious cause ie water ingress etc. The ECU was undamaged fortunately. It appears that a fault in one coil pack caused the other to part fail and blew the power relay. The thermostat is unrelated, she was just running a bit too cool, and it happened to play up at the same time. Interesting that the portable official Mercury diagnostic test kit could not in fact locate the faulty parts fully. Had to go to a full diagnostic procedure in the workshop.

The Suzy's were a completely new engine last year so no data to go on, but took the punt as spec looked pretty good especially fuel efficiency low down. Just feeding back a bit as Rustybarge requested, and for anyone else who may be interested. I'm as keen as anyone to see how they get on after 2,500 -3,000 hours, truly proven in the field so to speak.

No real problems with any of the dozen or so baby engines from 2 -4 Hp. Usual Honda (2Hp) plug issue, and the odd carb clean (thanks to all the additives gumming) has kept stuff going well.