4 Stroke 175 engine fail at high RPM

[slek777]

I have a Suzuki 175 on a BarCrusher 620 boat. I have had this set up for 4 years with great results until recently.
The motor cuts out completely anywhere between 2.5K RPM and 4K RPM.
With the check engine oil light, temp and rev light coming on and an alarm sounding.
I have had it to a Suzuki dealer which when he plugged his computer in it came up with no faults!
Can anyone give me some ideas?

[Moonlighter]

Barcrusher, means you are in Australia. I have the original design, a Surtees!

Welcome to the forum.

Where are you located? There are some good Suzuki dealers around, depending on where you are located. In SEQueensland, none better than Jon Eadie at Cleveland, Bayside Suzuki Marine.

I would say we are likely looking at an electrical problem here.

So first up, check all your battery connections. If the are any wing nuts on your batteries, get rid of them and replace with stainless hex nuts, clean all the lugs and connections, grease and reconnect them tight with a spanner. While you are there check the battery cables for corrosion. Also, check the main fuses in the harness which should be inside the transom, make sure no corrosion in the fuse holder and the blade is fitting snug. Check the White wire connection at the main switch and again, ensure the connection is clean, remove, wire brush, reconnect and tighten. Check the wire itself for any signs of breakage or corrosion near the lug. Also have a look at the master switch itself, it wouldn't be the first time one of them got corroded inside or broken. Does it seem to be switching on and off normally, not stiff?

Then I would look at the "dead man switch". The one with the lanyard attached to the throttle control box. If this switch is dodgy it would explain the sudden cutout and reconnection. You may need to pull the throttle box out and apart to check it. It is not uncommon for a fair bit of salt water to drip down onto that area in rough weather so this could well be the issue.

See how you go with that and let us know.

[Harper]

Kind of sounds like an intermittent electrical interupt. You'll have to start systematically checking all your wiring harness and connectors for corrosion or a broken wire. Start with the batteries, all power cables to and from the postive and negative busses. Could be as simple as a bad ground somewhere, but it's going to take some claose inspexction on your part. Also check fuses and the ignition switch. My idea is that your lights and alarm all come on when the electrical glitch reconnects, just like when you first turn on the ignition switch. That's why I'd recommend checking the battery/bus connection and ignition switch first.

[Harper]

Good evenin' Grant (or morning there. I guess)......

[Moonlighter]

Good evenin' Grant (or morning there. I guess)......

Afternoon, actually, Mike! It's about 4pm here now, only 28C but 85% humidity! Not as hot as a few days ago, though.

Guess it would be a tad chilly over there by comparison! And at midnight, too!

Getting ready for a family gathering, have just crumbed a few kg's of reef fish ready for the deep fryer, and have some inch thick slabs of Spanish mackerel ready for the BBQ, plus a few T bones!

In case we don't touch base before, Season's Greetings to you and yours. Hope you have a safe and enjoyable Christmas with plenty of good friends and good cheer.

Best

Grant

[Harper]

Thanks, Grant. I'm headed to the gulf coast to my brother's for Christmas. Yeah, it's fairly cool here, but I may haul the boat down there, and go after some red drum and speckled trout. Smacks (spanish mackerel) would be good, but they're probably gone till spring.

Merry Christmas to you and yours.

[slek777]

Thanks for your suggestions. I have looked at the batteries, everything looked ok but I gave it a clean in each terminal anyway. I have removed the throttle panel and given it a clean, but everything looked ok there too ( no corrosion). I wil just have to give it a run again and see if this has made any difference.

Ps Great day here in the south of Australia - Portland

[artdf175]

In conjunction with the motor cutting out is there any of the instruments showing some type of power failure?

Mike & Grant here's the a great holiday
My broken wrist with surgery has gotten in the way of fishing for a couple more months!!!!
Art

[artdf175]

One more question
After it shuts down what are you doing to get restarted?

[Moonlighter]

Ok, hi there in Sth Aussie! Nice part of the world, good fishing too!

I tend to agree with Mike, the fact that no codes are showing up suggests no major faults and thus more likely to be a simple electrical fault somewhere, and when it happens, a momentary cut of power stalls the engine and it then reconnects, with the lights and buzzer sounding the same as when the key is turned on.

Is that what it is like? Can you then restart straight away without doing anything else?

Have a look at the battery master switch as I suggested earlier. If it's possible to open it up or at least have a look inside it would be worth checking. Have seen a few of them fail over the years.

Also, as Art suggested, you should check the whole wiring harness from engine up to the controls and dash. Pay close attention to the White battery sub-wire. Sure as eggs, if there is a bad connection somewhere in that wire the power supply to the ECU gets interrupted and no ECu = engine no go.

Good luck, stick at it and let us know how you go.

And Art, will do my best to have a great holiday, not back at work until 12 Jan. hoping to get a few fishing trips in, all the best wishes of the season to you as well. Hope the wrist heals up quickly and you can get back amongst them!

[artdf175]

As I have noted several times -and I know each instance is slightly different- check all the splices and connections with the white wire off the battery
My main power goes throwing the battery switch
Off the battery switch is a short pigtail where the white wire is first spliced on with a connector. It was this connection that went bad. Copper wire just rotted off in the inside it was not until I applied some pressure pulling on the wire that I found the crimped ends were holding the connection together with nothing basically in between. From looking at it, it looked normal.
The same problem has been associated with the neutral switch as well

Thanks Grant looks like I will miss the winter steelhead fishing
I fell off from the side of the boat doing maintenance stuff fractured and dislocated a couple wrist bones put 5 stitches in the top of my head. Like I say-how long does it take to fall 5 1/2 feet (2 meters almost for you) answer: not very long Art

[slek777]

To answer Arts questions, check engine light comes on, oil temp and rev light come on and the beeper sounds. we then turn the ignition to the off position and then it will restart 9 times out of 10 straight away.

After cleaning all the terminals on the battery as suggested we took it out for a quick spin and it seemed to go alright, although it was a bit rough to go full noise.

I think it is strange that the local Suzuki mechanic hooked up his computer and it showed that no warning signals and lights had been activated.

Thanks for the information, it seems to be working at this stage only time will tell. Not a good thing to be happening though when you are 50km off shore!!

[Moonlighter]

The ECU records fault codes, and these mainly eminate from one of the engine's sensors.

If, in effect, your problem is simply that the power is getting cut for a second or two, then that would explain the lack of codes. No fault signal was sent, therefore no code was recorded.

Hopefully what you've already done solves the problem, but if not we have given you several more possible areas to look at, so they would be next on the list if the issue persists.

[artdf175]

I was lucky. The last time it did this to me it was in the driveway
I now pack a wire stripper, connectors and an extra bit of wire
The connection I described did this intermittent several times before it just quit
In my boat the white power lead also feeds power to the dash
I was wondering why chart plotter would just turn itself off
My battery compartment is located in back transom and can get all types of moisture to connections at times
Good luck on running it down
If you go for long rides suggest taking parts to fix a broken connection
Art

[redlowrey]

To answer Arts questions, check engine light comes on, oil temp and rev light come on and the beeper sounds. we then turn the ignition to the off position and then it will restart 9 times out of 10 straight away.

After cleaning all the terminals on the battery as suggested we took it out for a quick spin and it seemed to go alright, although it was a bit rough to go full noise.

I think it is strange that the local Suzuki mechanic hooked up his computer and it showed that no warning signals and lights had been activated.

Thanks for the information, it seems to be working at this stage only time will tell. Not a good thing to be happening though when you are 50km off shore!!

Dose the engine cut out in calm water, or when you hit a wave in rough water, also when the engine has stopped do all the lights stay on, or you switch the ignition off and then back on. The reason I ask, when you turn the ignition on all the lights will come on, the ecu will do a self check and if there is no problems the lights will go out. Pull the thirty amp fuse and make sure it is all right it powers up the main control relay which supplies battery voltage to the ecu, injectors, coils fuel pump and sensors. I don't think the problem will be in the fifteen amp fuse that supplies battery voltage for the ignition, because bar crusher have a separate fifteen amp fuse at the dash. Say for instance when you fly around the corner of the cork screw and open it up on a flat sea, will it cut out, or when you go round the rock in rough water. I too have a bar crusher and in Portland small world.