Sound after going to the mud

[kerby0825]

HI all, I am new in boating and fishing offshore.

I have a 2 stroke mariner 90HP (1998) and last weekend I went to a western port here in Melbourne (Australia). I went to very shallow waters (0.4m) by mistake and the engine practically was running in the mad. To the point that it was expulsing mud trough the water out hole.

Then, it was getting hot and a "bip" sound started. I turn off the engine and waited until it got a bit cold and moved it out the mud. I turned it on again and the water was flushing clean and the ?Bip? ended.

I went to many places later on at full speed. I did not have any issues and it was running very good.

I went home and flushed it as per usual and it was ok.

I tried to move the propela manually and hear a mild sound (like a cracking sound) coming from inside (around the arm between the propela and the motor head). I don't know if the sound was there before because I did not check it or it was caused by the mud.

Does anyone have a similar motor that can check if it has the same sound is coming?

What do you think?

Thanks in advanced if anyone can provide me with a point of view or help.

Thanks

Kerby

 

[Bifflefan]

Re: Sound after going to the mud

Welcome aboard.

Remove the propeller and clean the dirt out of the housing behind it. That should fix the cracking sound, if not you may have damaged the prop or the prop shaft.

The "bip" was probably the over heat alarm, or a low water pressure alarm. Either way they did their job.
I would suggest that you learn the water you are in are in before running into the shallows. You (or someone else) may not be so lucky next time.

 

[Grub54891]

Re: Sound after going to the mud

Just remove the prop,check for any debris around the prop and in the exhaust ports@ the lower unit. Its not unusual to get junk in there when running aground.
Grub

 

[kerby0825]

Re: Sound after going to the mud

thanks guys

I will check it soon.

Thanks

kerby

 

[kerby0825]

Re: Sound after going to the mud

Hi Guys,

It just to let you know what was the problem. I checked and the boat was in gear. The gear handle was just moved a bit forward (difficult to notice). I placed it back to the N position and the cracking immediately finished.

Thanks again.

Kerby

 

[BatDaddy1887]

Re: Sound after going to the mud

Also, if you have a depth finder on board, most of them have a shallow water alarm that you can set to warn you of that type of situation. I set mine to 3 foot (1 meter) to warn me.

 

[Texasmark]

Re: Sound after going to the mud

The crackling sound may have just been the overrun clutch. You said you didn't notice it before but it was always there if in forward gear.

To prevent serious disruptions to occupants of some marine engines (OB and IO I know of) designers put what's called an overrun clutch in F gear. Reason being on deceleration, the engine rpms drop below the propeller rpms. Were it not for the clutch the instant you cut the throttle the prop would respond which would be equivalent to throwing a "sea anchor" overboard on a non stretchable cable. Your teeth would wind up in the windshield if you had one.

So in N, the prop rotates with no noise. In F in a normal rt hand drive engine rotating the prop cw as viewed from the rear will get a clicking sound and a slight movement of the prop and shaft in and out of the gearbox...1/8" (3 mm) roughly. In R, carefully moving the shifter to the rear with the engine off and someone rotating the prop till engagement, you will get a lock in both directions with no in and out movement of the shaft nor prop.

HTH,
Mark

 

[kerby0825]

Re: Sound after going to the mud

thanks all for the replies.

cheers

Kerby

 

[quicktach]

Re: Sound after going to the mud

Hope you gave it a good flush and back flushed if you can!