Outboard Knocking Noise

[hopalot]

Had a few issues with my tinny over the last year and only been out a handful of times. 1992 quintrex fishmaster 96 evinrude 90hp. Finally addressed all the problems and took it for a run to the reef, you bewty ran like a dream..... but then running on the muffs at home a loud knocking noise was coming from mid lower unit. The noise is heard in neutral, forward, reverse and the prop still spins, and noise gets faster with increased revs. Dropped gear oil, one slight streak of grey, no metal shavings, compression test 120 on all four, no loose bolts transom. Asked a couple local shops to take a look but didn't seem the slightest interested, will see if any of the mobile boat mechanics will have a look in the next few weeks... Well the weather looks likes its great this weekend and my mate is taking his boat out and rubbing it in. Now I'm tempted to follow him out and hope for the best but knowing I got help if needed..... So I guess my question would be do you think the boat would just seize or go out with bang? because I really need to go fishing and I would rather kill this boat trying than have it permanently in the shed laughing at me but I don't wana kill myself doing it.

[Gon Fishun]

A $50 repair bill could turn into a $5000+ bill.
I would keep looking if I was you.

[Noelm]

Check gear cable adjustment, it may be just off and the clutch is catching the gear slightly, as usual, do the simple things first.

[purnong]

I had a similar issue many years ago with a 90 Evinrude, The knock sounded like a big end bearing was gone
After stripping the motor and finding nothing wrong we then went looking at the gearbox and found a broken tooth on one of the gears
That was an expensive exercise in the end, Just wish I'd looked at the gearbox first
Although when I eventually drained the gearbox oil there were metal shavings in mine

[liltuffy]

Check your timing, I had a 97 model Ocean Pro from new until a couple of months ago, great motor.

Those donks have an optical ignition sensor at the top of the motor - a word of advice, don't rub the face of the sensor with anything - you'll scratch and ruin it. Mine played up about a year ago - missing and carrying on like a pork chop. Anyway I was told the electronics "wear out" after about 10-15 years. I replaced the black box, the optical sensor, the high tension leads, coils, plugs, thermostats etc. Still didn't fix the problem - in the end Downes marine found the stator coil assembly was failing, we replaced that and she ran like a dream.

This may not be your issue but in the first instance if you know how to disconnect the shift pin and selector under the carbies and remove the gearcase, then run the motor with the gearcase off, you'll then know if it's powerhead or gearcase/midsection related.

Bloody frustrating mate but get your motor sorted, there will be plenty of other times to go fishing - your missus would probably like to see you came back as well.

Craig

I know this will piss a lot off but parts were purchased through boats.net for half the cost is Aussie.

[cormorant]

Just ideas

Drop the box off it and see if the noise still exists

Narrows down if it is motor or shaft and box but before I would do that.

Really depends on what sort of knock it is. I usually get out the stethoscope with a probe and try and prove where it really is on the motor as noise travels in a funny way.

Apart from the obvious crank pistons and spinny bits lift off the cowl and see it it is coming from the flywheel - magnet loose? Pinging with a batch of fuel? No oil about to throw a bearing.

Go the simple options first.

[hopalot]

Managed to calm myself this weekend with a day down the creek and some gardening... Talked to a helpful marine mechanic and he will come round and drop the leg one day soon, not to confident in the shift pin thingy, after watching YouTube and a bit of research on the net. I did remove prop and regrease it, double check compression, refill gear case oil and it still sounds like a high pitch clank coming from very close to prop, motor kicks over first turn and rumbles sweet apart from that. Will check gear cable adjustment when I figure out exactly where that is... Cheers for the input fellas, will keep at it and not play silly buggers til its fixed :-)

[gazza2006au]

your gearbox oil being gray is one indication of a problem u need new gearbox seals and if u think the clunking noise is coming from the gearbox i'd agree with noelm and say its just a simple gear shift off setting, follow your cables that run into the front of your engine there will be two the same a push/pull type of cable one connects to the throttle the other the gear selector, if u still cant find it remove the engine cover and have someone push the throttle forward while your looking at the engine (of course with the engine turned off) the cables that move are the ones u need to disconnect than restart the engine

[Fed]

Don't shift into gear without the engine running or turning the prop by hand.
OMC dog clutches are not spring loaded.
Buy a manual or take it to an OMC dealer.