Visit our Popular Forums

mtnbowhunter · 12-10-2016, 08:01

HI GANG
I just bought a new Suzuki DF20as short shaft manual start tiller outboard manufactured in jan of 2016. i just removed my 2006 mercury 15hp 4stroke outboard from my 12ft aluminum RIB and put the df20a on.
while i am still just breaking the motor in and have not been above 1/2 throttle, I have concerns about the following:

- the engine is quiet with regards to exhaust noise, but very noisey as it produces a LOUD high pitched whine at anything above idle that is a simular sound made in transmissions with straight cut gears. it is a very uncomfortable sound.

- vibration, at above idle, even at a fast trolling speed, it creates a vibration that shakes everything in the aluminum hull and at speed it makes the aluminum rib hull give off a loud buzzing/vibration noise that again is very uncomfortable.

NONE of these issues were noticible with the Merc 15hp 4 stroke!

YOUR THOUGHTS / EXPERIENCES PLEASE!

**a64pilot** · 12-10-2016, 08:18

Vibration is normal, its a vertical twin with no balance shaft, they could have smoothed it out but then it would have gained considerable weight.
Noise is not normal, I would take it back, mine is super quiet, vibrates, but no noise.

I'd still take it back, but that noise has me wondering if there is oil in the foot?

GRIT · 12-10-2016, 08:50

Mine has prop noise, which is high pitched, but the vibrations are not as you describe (Caribe C12). Aluminum does transmit vibrations well, perhaps some kind of harmonic?

Does it whine when in neutral too? Have you tried it on another dinghy?

I've heard of several people having the prop whining noise I have. But if yours is loud enough to annoy, I'd have to agree with A64. Check your oil.

Good luck.
Paul.

mtnbowhunter · 12-10-2016, 11:59

just had it on the lake again.
so out of gear , engine idling it is quiet, can hardly be heard, then go a little bit above idle and the whine type noise starts, if you take the engine cover off it is really noticeable, increase the throttle a wee bit more and the pitch /tone of the whine changes again. since the motor will not let you rev ikt up very high in neutral I can not use higher rpms.
do your motors emit the same whine type noise out of gear??

also. during the 20hr break in period, do the electronics limit rpm when in gear?
Thanks

**a64pilot** · 12-10-2016, 14:02

Mine really doesn't whine, now I don't hear as well as when I was a child, but no loud whine for sure, maybe a quiet whine, like a toothed cam drive belt whine maybe?
No their rev limiter is I believe the same, with the stock 10" pitch prop, mine would hit rev limiter quick, so I went with a 12" Solas SS which was too much, settled on an 11" Solas SS. I believe the SS Solas has much more cup on the trailing edge, and therefore more effective pitch. I bet a 10" SS Solas would be just right if loaded heavy, but I'm not buying a third prop.
I believe your aluminum boat has probably much less drag than a typical RIB and may need more prop, be faster than most RIBs too I bet.

I have always had small two stroke outboards, about the time you think it sounds like it's beginning to run well, it hits it's rev limiter. Being a four stroke it has half the firing pulses and just sounds much slower I guess.

Sent from my iPad Pro using Cruisers Sailing Forum

GRIT · 12-10-2016, 14:14

I think I'd give the dealer a call, and soon.

Mine never makes a noticable whine out of gear. You have to limit your revs yourself. It's hard to guess what the revs are. They ask for 3000rpm max, for something like two hours. We got it on plane, then slowed to the lowest possible speed, while keeping it on plane. Vary your rpm a little once in a while, but don't force it.

I later got the analyzing computer program for the engine, and it turns out that I was reving it to 4000 rpm instead of 3000 rpm. (Full history is recorded in the engine's memory) C'est la vie. Just don't abuse it for the first tank of fuel, warm it up, in gear at just above idle every time you use it, and keep the revs down.

After that first tank of fuel, you should be fine to use it as any other 4 stroke.

But call your dealer, something sounds bad with yours.

Good luck.
Paul.

**GordMay** · 13-10-2016, 03:55

Greetings and welcome aboard the CF, bowhunter.

mtnbowhunter · 13-10-2016, 07:56

I need a favour from one of the members here with a df15/20a fuel injected outboard in the water.
could you please start the motor up and after it has warmed up - remove the engine cover. then listen to the engine , at idle it is VERY quiet, then turn the throttle up just a little bit - does the your engine start to emit a very noticeable/audible whine type of noise - then increase the throttle a little more and the tone and volume of the whine, does it change(if it exists) ???

on mine I can hear it easily with the engine cover on but really really noticable with it off.

I am in a small rural area and the dealer is a 130 mile round trip away. since he is a small dealer I do not think he has sold many and would not know if the noise is normal or not and with no other motor in stock to test.
the rush is on now for me as I want to leave for our trip to Baja in the first week in nov.i f I can get some feedback on the issue if its normal noise or not it would immensely help.

mtnbowhunter · 13-10-2016, 14:47

PAUL;
WHAT analizing program did you get for the Suzuki, how easy and well does it work and any other info about it would be great!

GRIT · 13-10-2016, 15:23

I got a pdf service manual from ioffer.com. (Suzuki DF15A DF20A 4-Stroke EFI Outboard Service Manual for sale)

The power cable for the ecu I got from Brown's point.com (You need to energize the engine's computer with 12v, to have it talk to your laptop.

I got the OBDII diagnostic cable and software, service manual, from ebay: Suzuki Marine Outboard Diagnostic Cable Kit Plug Play Best Buy | eBay

That's it. It works great, you can change many operating features for troubleshooting purposes, and it gives you a breakdown of "time at rpm". Barometric pressure, timing, etc...

Sorry I can't get my engine in the water for you, in the near future, otherwise I'd run it as you requested.

Good luck.
Paul.

Sailuke · 13-10-2016, 15:36

Is it in neutral? my yamaha 8hp cant go above idle in neutral without making scary noises and vibration like crazy. its just because the engine is running fast with nothing to fight against. try running it in forward. is it the same?

ranger58sb · 14-10-2016, 05:39

I've not heard a whine from our DF-15A.

-Chris

marlinmike · 14-10-2016, 09:26

I will say going from a 8hp 2 stroke to the 20hp Suz 4 stroke it took a bit getting use to, in the beginning I found the vibration terrible, now after a full year doesn't bother me. Has a slight whine, but nothing bothersome for me.

mtnbowhunter · 14-10-2016, 14:21

HI GANG
I hope this works!!!
I have tried to attach a short video so you can hear the noise in my new df20a I have been describing.
engine is warm, out of gear, engine cover off, you can barely hear it idling and then the noise/whine starts as soon as you go off idle.
if any of you have your df15/20a fuel injected motors in the water, could you PLEASE fire them up, remove the engine cover, and see if it makes the same noise???
you can hear it with the cover on also, but the sound comes thru better on my phone with the cover off!!!!
I sent a copy to my dealer and he forwarded it to Suzuki, but I really need your input as from what I have read on forums, Suzuki service is,well, questionable!
Thanks

GRIT · 14-10-2016, 16:32

I'm pretty sure that's the belt. It does "whine" quite a bit louder than mine does, but it doesn't sound like it's going to fall apart. I think it's just tight. Mine does indeed have that sound, but it's more of a background noise.

If it still sounds like that after a few hours, then I see how you'd want to replace it.

Mine sounds like this one :