Suzuki DF20AS 4-stroke new - Any opinions? - Page 4

Fenlander · 03 March 2016, 00:01

Well the Aerotec hull is just a tad draggy and my experience vs other hull types is that it could be a knot or so down on yours with the same load... so you could be first in the chip shop at Brightlingsea.

jeffstevens763@g · 03 March 2016, 08:03

thats settled then gracious acceptance of defeat fish & chips supplied by the victor for his confidence in the right choice of engine possibly?

Stigomery · 03 March 2016, 09:56

Deal! (I like plenty of salt n vinegar)

Surprised to hear you say the Aerotec is 'draggy' Fenlander - I thought it was the Ferrari of the SIB world (it's even red)!

Apologies for derailing this thread...

Fenlander · 03 March 2016, 12:22

My only worry with the Chip Shop Stakes is the dealer looking at the usage data come service time!

As I say there is usually only a knot or so in it between SIBs but the Aerotec has a very deep V which can take more power to push through the water than any profile that is flatter... not that your Honwave is super flat but an absolute tea try of a profile will usually skim across the water the best.

It's not just the angle of the V but also that the Aerotec continues it right to the tramsom which reduces lift... and hence speed... compared to a design that flatten towards the transom.

The ultimate speed of mine is also somewhat reduced being in modest old guy grey.

Probably the first to the chip shop would be if someone came along with an F-rib which are not too deep V and fairly flat at the transom plus being GRP hulls lose that ... however small... flex nature of an inflated "rubber" floor which can lose speed.

jeffstevens763@g · 03 March 2016, 14:51

just read Suzuki have brought out 4,5,6 hp 23.5 kg motors that can be stored on the front starboard and port sides be good if the 20 was the same David

cheers

jeffstevens763@g · 08 March 2016, 14:58

just ran my 25 hp Suzuki engine up took fuel line off engine left ticking over 220 - 210 rpm ran for 21 mins till empty for info.

cheers

Fenlander · 08 March 2016, 16:58

I guess you mean an idle around 710rpm??

Anyway it's virtually running on fresh air at idle from the sound of it?

From what I can see around the net the fuel consumption of a 4-stroke might be 20-30% better than a 2-stroke of the same power in normal running but on the 20hp Suzuki supply a tank half the size of my existing Mercury 15. Might have to get a larger one.

Max... · 08 March 2016, 17:06

Fenlander is right re' the draggy hull - in my experience too. My 3.4m Zodiac Fastroller (flat type SIB bottom) with a 9.8 was faster than our Aerotec with a 15. BUT it's a bit like the old Landy saying - "You go fast, I'll go anywhere" or more suitably: "You go fast (on flat water) I'll go out in the bigger stuff and if you dare then I'll be faster" or something like that...

jeffstevens763@g · 08 March 2016, 17:13

Quote:

Originally Posted by Fenlander

I guess you mean an idle around 710rpm??

Anyway it's virtually running on fresh air at idle from the sound of it?

From what I can see around the net the fuel consumption of a 4-stroke might be 20-30% better than a 2-stroke of the same power in normal running but on the 20hp Suzuki supply a tank half the size of my existing Mercury 15. Might have to get a larger one.

showing 220 on the rev counter didn't seem right was going to have a look in the manual but it's certantly low reving and very quite but suspecting the £10 rev counter not a true read out.
I think you will be surprised at the fuel consumption when you get yours.
Should be 850+or-
Cheers

Stigomery · 09 March 2016, 08:07

Quote:

Originally Posted by jeffstevens763@g

showing 220 on the rev counter didn't seem right was going to have a look in the manual but it's certantly low reving and very quite but suspecting the £10 rev counter not a true read out.
I think you will be surprised at the fuel consumption when you get yours.
Should be 850+or-
Cheers

There's another thread on these cheap tachs... I have one... when it registered 2946 as the WOT RPM Poly pointed out that my low idle revs of around 300 were probably 50% of what i was actually doing, ditto at WOT... perhaps your tach is like mine and reading 50% of actual.

jeffstevens763@g · 09 March 2016, 08:35

Quote:

Originally Posted by Stigomery

There's another thread on these cheap tachs... I have one... when it registered 2946 as the WOT RPM Poly pointed out that my low idle revs of around 300 were probably 50% of what i was actually doing, ditto at WOT... perhaps your tach is like mine and reading 50% of actual.

thanks stig not an expert but mine seams to be reading 1/3 ish i wonder if its because its only on one lead out of three?

cheers

Fenlander · 09 March 2016, 08:46

Jeff you said above the tach was showing 220/210rpm and your Suzuki has an ECU controlled idle speed of 850rpm +/-50 so more like it's showing 1/4 revs.

I forget which small tach you have but does it allow any setting changes in a menu?

Stigomery · 09 March 2016, 08:49

1/3 sounds better... I have 2 cylinders and therefore your assumption could be correct. I tried wrapping the tach lead round both HT leads to see if it made any difference but I still got revs counted in the 300-450 range (engine wan't warm so it wasn't idling without a little assistance every so often)

chipko · 09 March 2016, 09:25

There seems to be more than a few guys of late reporting some fairly wild readings off your cheapo tachs.
They are usually adjustable and below are some instructions on set up, which hopefully may help you get more realistic readings.

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Stigomery · 09 March 2016, 09:32

Can't speak for others, but mine has no buttons, controls, switches or other means of input... It has an LCD and a wire, nothing more... But you get what you pay for...

Max... · 09 March 2016, 10:47

Still sounds too low - idle of 440? Maybe it's 25%??

Max... · 09 March 2016, 10:48

Quote:

Originally Posted by Max...

Still sounds too low - idle of 440? Maybe it's 25%??

What happened there? Just replied to the Suz' topic??

Fenlander · 09 March 2016, 11:38

>>>What happened there? Just replied to the Suz' topic??

Well you did... this is the Suzuki topic!

>>>Maybe it's 25%??

Yep pretty sure of that... as I mentioned above these Suzuki's have a fixed idle maintained by the ECU at 850 +/-50 so if you like you can use the outboard to check/set the tach.

The tach I bought has 7 spark sensing modes for different engine types. It shows how to select in the menu for the various options but then has a final note that if it looks wrong at idle it probably is... so to change the mode to one that gives a more realistic idle then it will be correct for higher revs.

Also I mentioned in the tach thread I made sure I bought one with a coax sensor wire with a ground wire for the shield which is how the expensive Tiny Tach is made. I can see there is a real possibility in more modern engines... particularly the EFI models with injector wiring... for stray pulses to upset the tach model with a single core wire.

jeffstevens763@g · 09 March 2016, 12:15

guys didn't really research the tacho because i was just after the hour meter originally but mine is a cheapo no buttons so probably no good so i get another sorted and to be honest its fell apart twice it is sealed but looks like not whats needed.
which one did you buy david
cheers

Fenlander · 09 March 2016, 12:32

It was this one Jeff..

Digital Hour Meter Tachometer Adjustable Resetable Job recall max rpm + service | eBay

Of course I haven't tried it yet as the Suzuki isn't here. It should have arrived at Suzuki UK in Milton Keynes on Monday with a possible arrival at my dealer today, next Wed at latest.

I'm trying so hard to be calm and not to ring them jumping up and down... "Is it here yet"!