Suzuki DF20AS EFI - Impressions and review.

[Fenlander]

Yep running in stage 1 and most of stage 2 complete!

What a superb day... just a bit of a chill in the northerly wind late afternoon but apart from that really nice.

So some proper impressions now...

Instant 1/2 pull start, dead stable idling and clean acceleration. A different type of vibration to the 2-strokes with an almost offbeat feel just above idle (commented on in some tests). Staggering quiet at idle and a nice muted 4-stroke sound at higher revs. Feels very gutsy and has a very sharp pickup from idle.

The "lean burn" ECU controlled mixture operates by giving loads of fuel to accelerate then leaning off as much as possible while maintaing revs for any given throttle opening. In some tests they've commented you can feel this happening and there is an impression having levelled off the throttle that you might be about to slow down so you give it a bit more where it responds with gusto then you have to back off again. I'm being super critical here... not an issue... but after the gutsy through the range 2-stroke it just feels less linear in its power delivery.

Running in (after initial 15mins at idle) is a couple of hours at 3000rpm which gave a just off the plane 6kts and then an hour at 4000rpm which we did most of... this gave an on the plane 12kts. Then we have 7hrs of max revs allowed but only for 5min periods.

We covered 14.6Nm and used 5lit fuel so (thinking of Max's recent thread) 2.92Nm/lit.

There was one panic... about 1.5Nm from shore the engine spluttered and cut out... I looked down at the kill cord as the first possible culprit... still on. So I restarted which lasted all of 5secs. Then it wouldn't go at all. Picked up the tank which felt half full and started to think of where to paddle to!

Then I remembered daughter had put her feet on the fuel tank shortly before and looked more carefully. She'd put pressure on the collar of the tank to fuel line snap-on connector and it had released with the ball valves sealing fuel off... but was hanging on enough to look connected.

Reconnected, primed and off we went again. An outboard stopping at sea always concentrates the mind.

Thank goodness I refused the 12" pitch prop that was on this outboard when it arrived... even the 11" they substituted is a bit high geared with the three adults + dog + 24l fuel + lots of kit. Think I'll buy a 10" and keep this 11" as a just in case holiday spare.

Anyway I've saved the best for last... with a 20mm spacer no transom splash at all! Given all the varied ideas I was considering this year to reduce splash further (with the Mercury) I'm really pleased at this improvement... really really pleased!

Pics... on the hard... running in at 3000rpm displacement... and 4000rpm on the plane.

Edit: The last two pics remind me how much I hate raised transom wheels spoiling the lines of a SIB... but they're so damn useful. Thanks G!

[Stigomery]

Sounds like you had a great day! From where I was sat in Cambridge it looked a prefect day for it...

Glad I'm not the only silly ass that disconnects his fuel line from time to time!

[Fenlander]

Only the second time in a lifetime it's happened to us. Of course if I'd had a choke I'd have fiddled with that!

[Fenlander]

Easiest power upgrade ever today... my 20hp sticker arrived!

[willk]

Originally Posted by Stigomery

Glad I'm not the only silly ass that disconnects his fuel line from time to time!

Oh, it's a sizeable club - welcome!

I eventually taped mine onto the tank...

[jeffstevens763@g]

Up date had engine service at ribquest £65 + vat today done at 6 hours for 20 hour or 1 month service to keep warranty up I questioned the 1 month it appears that some manufactures use a lighter oil for running in.
Engine oil and gear oil changed and I was very surprised how dirty both were, I didn't get a print out as their software needs updating to my engine spec (first 25 hp they have done) but no problem I can return for that later.

As a reference they charge £35.00/hour + vat the last cost I got was for a full all singing service tappets the lot at £257.00.
Costs inclusive of parts.


Cheers

[Fenlander]

My supplier quoted a bit less but I reckon when I get to the 20hr he'll probably "remember" his quote didn't include parts, oil or whatever so I'm expecting nearer your figure which seems OK.

Bit surprised the oil in either engine or g.box would be dirty at 6hrs but I wonder if it is a special running in fill that does initially pick up contaminants.

Sadly family arrangements failed to dovetail with weather/tide a few days ago so I missed getting another 3hrs on the meter.

New 10" prop arrived yesterday to augment the 11" my 20hp came with. Genuine Suzuki and like the 11" not nearly as nice a profile as the ones on the Mercury/Mariners I've owned. These Suzuki props look to lean a bit towards a high thrust design. They certainly grip the water though and there's a very marked snap to the action when you open the throttle compared with any other up to 20hp motor I've owned.

[jeffstevens763@g]

Re the oil your completely right picking up the sworfe & casting contaminants. Re the props we worked with stone manganese on ship propellers for a while the silence behind them is imence and designed to the engines & hulls so I would say with so many variants on hull design with boats getting the correct prop for each application is not easy.

Che.ers

[Fenlander]

Tank and fuel line upgrade today.

The Suzuki DF20 comes with what I regard as the standard 12l tank which I've had before marked Tohatsu. The Mercury/Mariner 2-strokes came with a 25l tank for anything over 15hp and that's what I'm used to. Of course the Suzuki is more economical but not as good as half the usage so effectively I've suffered a range downgrade.

Thought the answer was to take out a second identical 12l tank I already had but the two of them took up too much floor length. Also the new Suzuki tank didn't have a fuel gauge plus the fuel line is very easily kinked.

So today I've had delivered from Pacermarine a Quicksilver 25l tank with a Quicksilver line ending in a Suzuki fitting (£69-95 inc delivery).

As the images show the 25l Quicksilver takes up little more room than one 12l Suzuki tank, it has carry handle stowage for the fuel line plus a built in gauge. Also the fuel line is anti crush/kink compared to the soft Suzuki one and the connection to the tank is far better protected compared to the Suzuki type that only needs a nudge on the spring collar for it to disconnect.

With hindsight I should have twisted the dealers arm to swap the tank on collection day for a 25l at no/minimal cost.

[jeffstevens763@g]

Could you not piggie back the 12 onto the 25 for long range couple of bits of foam to rest on and strapped up.

[chipko]

Hey Fenlander,

If ever you want to dispose of the Suzi 12l tank and line please pm me. Kinky doesn't bother me.😀
Might be interested.
Cheers, chipko

[Stigomery]

Fenlander, is this for multi-day trips? Reason I ask is that during the (albeit low number of) trips I've so far had on river and sea I find it impossible to make a dent in the fuel.

I've been carrying a small 5l can as a reserve but as said I've not even used 1/2 a tank on a single outing.

Perhaps because I've been going solo the times I have been opening the throttle and also I've not been caning it for long periods?

I do have a big old 5 gal fuel tank that was for the 55 I could clean up if I do need a long range option I suppose - assume a good rinse in fresh petrol would clean out most of the old 2-stroke gunk.



(Future planning)

[Fenlander]

Chipko I appreciate the offer but I'm keeping the original Suzuki tank/line in case I sell the outboard in the future then I'll have everything as supplied new... I even took the original packing box from the dealer and it hangs in the garage roof now.

Yep weight is a factor Stig no doubt as the throttle opening to get on the plane is noticeably higher with 2 adults, 1 teen, dog, kit (& all that fuel!) than on a solo outing. I'm almost never solo.

Also... and not thought of it until just now... the pronounced V of the Aerotec particularly when well loaded doesn't skim over the water like some SIBs so is probably not as economical on fuel as others for any given outboard size.

On his report of the new Yamaha 6hp 4-stroke Gurnard managed 22.25Nm on 5lit and on our initial trip we managed 14.6Nm for the same amount of fuel. Given the difference in boat size/overall weight, hull profile & outboard size I'm happy enough with our fuel usage.

There's an old rule for fuel when boating of a third out, third for return and a third for the unexpected. Well I'm super cautious and prefer a quarter plus a quarter with half left in reserve. So a 12l tank on that calc doesn't give me enough of a day out.... particularly on our two week Scottish holidays where it's all a bit remote.

Final thing is that most of our longer distance outings are in Scotland and this year for example it's a 24ml round road trip to the petrol station from our cottage so the more we can buy each time the better.

If you wanted more range that big old tank would be perfect... as long as it was completely empty then just filling with neat fuel will be fine.

[Max...]

Stig, useful idea here:

http://www.rib.net/forum/f50/sib-fuel-use-71407.html

It is all so dependant on use - we are mainly on the sea and out there a 12l is useless - would go through that in 20 nm with no reserve. Mucking about in waves or skiing etc 10 litres would only do 15nm. I even get nervous with our 33 litre bladder nearly full sometimes.



Bladders are brilliant as they keep the whole floor area clear and hold so much as well as balancing the boat nicely with the skipper opposite.

[jeffstevens763@g]

Originally Posted by Max...

Stig, useful idea here:

http://www.rib.net/forum/f50/sib-fuel-use-71407.html

It is all so dependant on use - we are mainly on the sea and out there a 12l is useless - would go through that in 20 nm with no reserve. Mucking about in waves or skiing etc 10 litres would only do 15nm. I even get nervous with our 33 litre bladder nearly full sometimes.



Bladders are brilliant as they keep the whole floor area clear and hold so much as well as balancing the boat nicely with the skipper opposite.

Max

Where did you get your bladder from?

Cheers

[Stigomery]

Originally Posted by jeffstevens763@g

Max

Where did you get your bladder from?

Cheers

I looked at bladders, they're bladdy expensive!

So as not to derail... linky

[Max...]

Second hand - pretty good price that way but agreed, very pricey new - mainly as no-one except the military/commercial rescue boys seem to buy them and as we know they always happily over-pay for everything. Got mine from Whisper on here - maybe PM him or Matt H who seem to find these things quite often.

[jeffstevens763@g]

Originally Posted by Max...

Second hand - pretty good price that way but agreed, very pricey new - mainly as no-one except the military/commercial rescue boys seem to buy them and as we know they always happily over-pay for everything. Got mine from Whisper on here - maybe PM him or Matt H who seem to find these things quite often.

Ah seaflex I deal with them for lift bags cheers

[Fenlander]

Well we've had another day out with the Suzuki. It now has 6 of the 10hrs needed to run in and at this stage is allowed full throttle for a max of 5mins.... oh if only the easterly breeze and sea state would allow! As so often happens we had a decent run out but by the return when I wanted to trial speeds/revs the sea state was not ideal once we headed back into wind.

I'll report more in the thread... http://www.rib.net/forum/f36/suzuki-...ize-71830.html but with our hefty loading in the Aerotec it feels far more gutsy and responsive with the new 10" pitch prop compared with the 11" pitch it was supplied with.

Also by re-trimming the boat to be a little less bow heavy the slightly heavy feeling to the tiller steering I'd mentioned has gone.

It really had to work hard today as by mid afternoon it was gusty and once the tide turned against wind it produced a typical short chop added to larger waves with windblown crests. Typical shake your teeth out weather for SIBs so I was on and off the throttle much of the time to make best progress and keep crew in the boat... so no real chance for it to drop into its lean burn mode.

So given load carried and the conditions I was quite happy with 8l fuel used for 18Nm.

We have adapted our way of handling the outboard so it is lifted less one-handed and doing this it's proving less stressful at 44kg than my previous "it's OK I can manage on my own" efforts with the old 36kg 2-stroke.

No more to say really... thank goodness after the outlay and taking a chance it would suit it's turned out a total success.

[Fenlander]

Much better weather yesterday for a modest 14.1Nm trip to find a cafe lunch.

We completed between the 6hr and 8hr running in period... just two more and it's finished.

Carrying our usual robust load we cruised at a very comfortable 14-17kts all the time we were out of the 4/6/8kt limits.

I tried premium unleaded this time and I'm sure it was a bit smoother... but could be wishful thinking. Regardless I will continue to use it.

Fuel used was 4.5l for the 14.1Nm. So far then fuel usage has been...

Hours 0-3 (slower speeds) 0.34 l/Nm
Hours 3-6 (difficult conditions lots of on/off throttle) 0.45 l/Nm
Hours 6-8 (yesterday, mostly cruising on the plane) 0.32 l/Nm

According to Suzuki with a lighter load (ditch both crew, dog and half my fuel) and a more skimmy floored SIB I should be able to get down to 0.2 l/Nm at a 14kt cruise.

Still no splash ingress into the Aerotec... about half a mugful after the whole day and most of that was from me jumping in from knee deep water.

Not related to the outboard as such but one image shows us just starting to pack up... from the perspective of ever present onlookers it really is a case of is that lot really all going in the back of the car.