kmcrosby78

Engine Problems - Any Ideas?

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G'day all,

Wondering if anyone has any ideas on what the problem is I experienced with my 90hp 4-stroke Suzuki motor yesterday. On the way out I saw some tuna & birds working so slowed down then knocked it into neutral and then while I was getting a rod, the engine cut out. I can't recall but it may have done again when pulling up trying for whiting. When we got back to the ramp and were milling around waiting our turn to access the pontoon it cut out again and wouldn't restart. I trimmed the motor up to ensure nothing was tangled but all clear, tried again and it fired up again (doubt this would have anything to do with trimming it up and then trimming back down again) but again cut out. We luckily drifted with the wind to the public mooring outside the Tide Bar. It alternated between not starting at all or starting but not remaining idling and cutting out. Wasn't sure what to do but decided it was worth taking a punt and trying to run it back against the wind to the pontoon and I tried to keep the revs up a bit as this seems to be possibly the issue.

It was its first run since a service. I've now realised/remembered that it did this at the ramp the last time I took it out and I didn't actually tell the marine mechanic because at the time the oil light was blinking so at the time I assumed it might be linked, but now I'm probably thinking they weren't related (the oil light was just indicating it was due for an oil change - 700hrs) so I probably should have said something so they knew to check it. Should this have been noticed as part of the service anyway? Do they normally run them in a tank and check them through their gears? @Drop Bear mentioned today that they may need to just fiddle with the revs at neutral?

Any advice appreciated - scared the wife a bit ....... 🙂 

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Did the plugs get changed at the last service? On my last boat I had a very similar experience, saw a makeral bust up pulled up to neutral and motor spluttered and died. Would restart ok but not always on first go. That same day same thing happened to me at the ramp. When idling engine would die. Did the same thing kept the revs up and luckily had fenders and other boaties around to help. Marine mech Diagnosis was I had fouled plugs or potentially an injector dying.

plugs u can check, injectors if you have a multimeter and service manual u can check the resistance of certain pin combinations is within tolerance of the service manual to diagnose.

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Hi guys,

Do your techs have the computer systems for these suzuki's. It is mandatory for them to run the engine with the computer as well as doing a fault check prior to servicing. Anything Barr a few small things will immediately show and they are then logged and fixed. Once this is done the motor must be loaded tested and checked with the computer. All said and done then that information should be logged with suzuki for warranty reasons. 

Four strokes are pretty much bullet proof but can develop their own issues but the right tech equipment will solve that. If it is a injector that will reflect and can be tested with the computer so just ensure the technicians have all that is needed. 

Hope this helps

Regards Rob

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Belated thanks for the replies @Hweebe and @Robert Allen, much appreciated. I managed to locate the invoice from the service and the spark plugs were replaced. I'll give them a call this week and find out if they ran it on a computer to check for faults - I don't have much mechanical knowledge unfortunately so am not even sure if all outboard mechanics have this technology? Hopefully it's an easy/cheap fix and I can get back on the water - just need to find the time to pop it in to them now, grrrr!!!  Will report back 🙂 

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Had a similar problem on a mates boat a while back with a 250hp zuke.  ended up being a valve in the injectors that controls the fuel/air mix, was stuck on air so no fuel getting in.  very similar symptoms to yours.  although we were 95km from the wide bay bar when it happened...

 

I'd get them to run a diagnosis on your injectors,  they are extremely sensitive to water in the fuel so make sure your filter is working and drained each time.

 

 

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Am taking it back to them tomorrow for them to look at next week. When I explained the symptoms on the phone, the guy's first thought was that it might be the IAC (Idle Air Control - or choke in layman's terms). @Robert Allen I assume that's what your point number 1 is referring to? 

The service invoice indicates that they cleaned the fuel filter on the engine - is this sufficient or should it be replaced each service? (I have no idea ...).

It also states that they reset the service code which was causing the oil light to flash - so I'm assuming they have done this properly. So it's looking like the IAC might be the most likely problem. Is this an easy/cheap or complicated/expensive fix?

Will report back (and hopefully get out for a fish next weekend .... 🙂).

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This should be an easy fix and with the systems we have we can do that via the computer. It's a little complicated to explain how but if the have the tech equipment should happen quickly. 

As for the fuel filters I am not sure if yours are still the paper ones or plastic. Will research the Aus motors and get back to you. 

Hope they get it right

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Dropped the boat back to Mikes Marine at Capalaba on Saturday and picked it up this arvo. He's confident it was a build up of crap around the IAC - I asked if there's anything I can do maintenance wise and he said it just needs a spray each time it gets serviced, so I'll remember that one. He ran it on idle for about half an hour without issue, so I should be back in action. No charge so I have confidence in their customer service moving forward.

Sounds like the spotties (large females) have turned up in Moreton Bay so I'm hoping to get out looking for them on Sunday.

Thanks for the advice fellas, appreciate it.

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Well I am very happy to hear that the sensor is now correct. I don't mean to sound like I am doom and gloom but was the motor idled under load in other words in water or just with a hose pipe. I have just completed a job on a 175 suzuki today and experienced the same symptoms and did a similar process as your techs. Once tested on the water it was A1 good to go. 

So just a tip that we use here, is once you have launched and before venturing out take it for a run by ensuring it's firstly at temperature (running) and then take it from zero to hero for 2 minutes and repeat twice. Bring it back to idle as Fast as you can and then idle for 5 minutes should the motor run true thumbs up but if it drops it's revs and comes back after a short time you will need to have the sensor replaced. 

However I trust they have got it right and going after those fish sounds awesome. Hope you catch loads.

Tight lines

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Thanks Robert. I'm not sure but I know they have a large flush tank there so am hoping/assuming they used that. I'll do as you've suggested and fingers crossed it'll pass the test 🙂 If I do need to get a new sensor, are they expensive to buy/get installed?  Cheers for your valuable input, much appreciated.

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No, the sensors should be well priced in Aus. But here in S.A. they are to say the least very expensive. I looked up your prices on the suzuki forum and they are amazingly cheap. However I do believe you are sorted and the issue is history. All you need to do is fish and fish. 

Enjoy your boating

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Let us know how you go @Drop Bear. I heard there were schoolies (the fishy kind, not the pimply kind) in the northern bay but that is a bit too far for my tinnie so I am taking a mate to the Pin tomorrow for a bread and butter session. Let me know if you find them closer to home and I might have a crack on Friday.

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