2013 DF140 engine skipping during acceleration

[Ed8029]

I have a 2013 df140a engine and it skips during WO acceleration until boat plains out. I have replaced fuel hoses, filters and LP pump. It also starts surging if you keep it at 4000 rpm while cruising. Doesn't seem to skip holding at 5000 or higher while cruising. I get a check engine code every once in a while 3-6 which is O2 sensor I think. Engine stalls sometimes when returning to idle but starts right back up. Engine will idle with no issues. Could o2 sensor be causing my problem. any help with this will be greatly appreciated.

[Harper]

Yes it could be the oxygen sensor. It sounds like a malfunctioning O2 sensor is causing your engine to run too lean, especially during acceleration. This is not a good condition to be running under, as running lean enough to cause misfires can do damage to the engine. I would suggest that you get the motor to a service center where they can hook it up to the SDS and get a reading of the situation. The fault history will be readable with the SDS.

[dlnw98]

Did you ever have the throttle body and/or the ECU replaced on your engine under warranty? My 2013 DF140a experienced a similar stalling when it was returned to neutral idle, and the mid-range RPM surge as you describe. This occurred even when the engine was near-new

I did not have a check engine light or any miss (skip)

A new ECU and throttle body under warranty solved the problem.

[coldfoot]

140hp 02 sensor

I have the same problem 3-6 code on a 2015 DF140a with 220 hours.
Currently waiting on the 02 sensor to ship
Larger Suzuki outboards have had the same issues with 02 sensors.
Suzuki has redesigned the 02 sensor and sometimes replacing the cpu
under warranty on larger outboards.

Its too bad Suzuki doesn't address known issues.
Good Luck

[Moonlighter]

If you get the 3-6 O2 sensor warning, you can still run the engine safety, it simply wont run in lean burn mode.

So the missing reported by the OP is very unlikely to be related to that. Likely he has 2 separate issues.

BTW many owners never experienced issues with the original O2 sensors, in fact it is a quite low percentage, which is why Suzuki is only replacing them when a problem is experienced, especially considering that the engine still runs fine, just not in lean burn mode.

If by "skipping" the OP means the engine is misfiring when accelerating, which means it is likely to be missing when under load, then I would be looking at spark plugs and leads. It could be as simple as a spark plug lead not firmly attached to the plug. Or a bad plug. Check the leads first, or pull the plugs and see which one looks different to the others. If the dealer connected it up to the SDS computer, it would show up quickly.

The early 2012/13 DF100-140 A series engines had a ECU recall, so make sure you have had that done, most of the time the dealer replaced the O2 sensors at the same time as the ecu recall was done, if issues were reported.

My recollection is that ecu recall this was due to a faulty water in fuel algorithim or some such in the ecu, again it was not critical.

[Nayna32]

Did the lean burn start in 2016 on the DF115 and Df140A?

[Ed8029]

Thanks for all the info.
I have boat a dealer now. Should know something later this week.
I will post findings of what is found to be causing problem.

[Moonlighter]

Did the lean burn start in 2016 on the DF115 and Df140A?

Started when the A series was introduced.

[coldfoot]

02 Sensor 3-6 Code WARRANTY UPDATE

General Electrical No 16

Model Affected engines DF115A/1140A, 250AP/300AP
519999 and earlier engine numbers

On the models listed above, under certain operating conditions the heated oxygen sensor may trigger a 3-6 warning to the operator and store the
diagnostic trouble code in the Engine Control Module(ECM).

If you have a unit in your shop that displays a 3-6 code order a replacement
heated oxygen sensor, and holder using part numbers listed below.

1 remove the original heated oxygen sensor.

2 Install the holder with sealing washer in the location of the original heated
oxygen sensor.

3 Thread the new heated oxygen sensor into adapter.
connect the sensor lead wire.

4 file a warranty claim for the repair

Parts information
18213-98J20 Oxygen Sensor
99103-94431 Sensor Holder

Model Failed Part # Replacement Part#
DF115A/140A 18213-98J10 18213-98J20
DF250AP/300AP 99103-94431

[Ed8029]

Got boat back yesterday and dealer said there were over 100 fault codes for oxygen sensor. Sensor was replaced under warranty. No other codes were found. No misfire was detected by sds but he said it seemed like the prop was slipping. RPM would jump by 400 at times. I am currently running a 4 blade 13 1/2 X 16 stainless. He said i could try adding a hydrofoil to the foot to help or try a different blade. Said i may want to try a 3 blade 13 1/2 X 17. Any ideas?

[Moonlighter]

If the prop is losing grip, before changing anything else, check your engine height. The sticky on propellors and engine heinght tells you how to check it, and if necessary, how to raise or lower the engine so itbis right.

If there us only an occasional slip, you could send your current prop to a prop shop and ask them to add sime cup to it, if you tell them whatbit has geen doing they can advise how much cup might be required. Cupping will help it to grip better and may eliminate slip. You may lose a few rpm, though not much.

What rpm can you currently reach at full throttle, engine trimmed out?

Again please read the sticky thread re props and engine height and you will understand why this is important.

[Ed8029]

I can hit rev limit at 6200 with boat trimmed out. I have a Caravelle Razor and it has a tunnel hull. I was told by previous owner that the Motor has been moved up and down to try to fix issue and many props have been tried but none have stopped prop from slipping. I added a hydrofoil yesterday and it seems to plain out a lot faster and i don't notice the slipping as bad.

[Greg Moore]

I assume by 'rev limit' you mean the upper end of the normal operating range which 6200 is, the actual rev limiter comes in higher than that on a 140..

If you're hitting 6200 full throttle there's nothing wrong unless you're propped to hit say 5700 full out.. My pontoon (2013 140a) is propped hitting 6200 at max speed. I will be getting a 19" as soon as Solas makes some but 6200 is where I should be with the 17 on it..

[Moonlighter]

I can hit rev limit at 6200 with boat trimmed out. I have a Caravelle Razor and it has a tunnel hull. I was told by previous owner that the Motor has been moved up and down to try to fix issue and many props have been tried but none have stopped prop from slipping. I added a hydrofoil yesterday and it seems to plain out a lot faster and i don't notice the slipping as bad.

Well, it would have been very useful if you told us about that in your first post. I never cease to be amazed at how relevant information is omitted from requests for assistance, and is only forthcoming well down the track!! We do not have a crystal ball, we can only work off info you provide.....

Is there anything else that has been done or told to you by PO or mechanic that you want to tell us about? Far better to tell us more about whats been happening than leave us to guess.

So, now we gather that prop losing grip seems to be the problem, rather than an engine that is not running properly....

Some hulls are more prone to this than others.

So before we make any more suggestions, how about posting some photos showing the stern of the boat, viewed both from the side and from behind the motor. Include a couple that lets us see the lower leg of the motor relative to the line of the hull. The more photos the better.

Because this is no longer a "Suzuki" problem (its now likely a propping problem) it would be worth consulting with a expert prop shop - if you're in the US, talk to Ken from the Propgods.com, he is one of the most knowledgeable people around on props. Possibly he has come across a simlar boat/motor combo and can make relevant suggestions to you.

Im not a pop expert by any means, for what its worth my limited knowledge includes that generally:

1. a 4 blade prop will create more stern lift than a 3 blade, so you may have too much stern lift that may be contributing to the prop getting cavitation.

2. A smaller diameter prop than optimal is more prone to slip than a larger diameter. Normally you would find a Suzuki 140 propped with a 14" 3 blade prop.

3. On normal mono hulls running DF115/140, the Suzuki 3 x 14 x 20 stainless prop nearly always performs very well. Run one on mine and it is spot on.

[D'oh999]

When they rigged my boat in August, they wound up with a 14x23 Aluminum. I made the deal with a SS so they had to order it.

14x23 Aluminum, 6100 rpm, 47 mph GPS, 1 person full of fuel.

The SS, 13.75x23, 6100 rpm, 48 mph GPS 1 person full of fuel.

But, mid range is a whole different motor, and Blow Out (ventilation) is gone. Proposing is far worse at WOT with the SS, I have to trim in a lot more.