Stupid noob with minor overheat.

[rotorhead511]

Hello all, first time poster. I'm a new boat owned and had a little issue a couple days ago.

I was trying to get to a friends dock at low tide and started to touch bottom. I aborted, raised the out drive a little and started to back up. It needed some omph so I gave it and got the overheat alarm.

Not sure if I was making too much cavitation and not getting enough water in for cooling. It didn't last long as I got clear of the bottom and lowered the drive. The alarm went out after a very short time and I saw the temp quickly get back to operating range.

My best guess is 10 seconds or so of alarm.

The boat operated fine back to the ramp.

I went home and flushed it due to salt water exposure and noticed I only get water out the right side port. Being new to boating and doing my first flush I wasn't sure if I should be getting water out both sides. I was getting exhaust out the left port but no water.

I Googled overheating a Mercruiser 3.0 and got check water pump and exhaust shutter.

Long story short, is there an easy way to check the exhaust shutter and should I be getting water out both exhaust ports at idle? And with little water in the cooling system from tilting could I have damaged the impeller?

F'n noob's.

Thanks

 

[alldodge]

I would pay no attention to what side the water is coming out. While it normally comes out both, this depends on other things like, amount of water supplied by the hose, crud on one side more then the other, and obstruction. The exhust ports your looking at are relief ports and not the actual exhaust port which go thru the prop hub.

I would be more concerned with the impeller in the drive. If you did suck up some crud then this could damage the impeller. Just watch the temp closely for a time and see if it gets above what you normally see

and :welcome:

 

[rotorhead511]

Thanks for the reply. What are your thoughts on the overheat?

 

[alldodge]

Thanks for the reply. What are your thoughts on the overheat?

When the drive is in reverse it stirs up air and can cause cavitation. The air will reduce cooling and does cause overheat

 

[rotorhead511]

Could I have done any damage in that short of time?

 

[Bondo]

Could I have done any damage in that short of time?

Ayuh,..... Welcome Aboard,...... It depends,.....

If it was from airiated water, as AD suggests,.... probably no issue at all,.... 'n I agree,....

If there was a blockage, the shutters, 'n the impeller die 1st,.....

Unfortunately checkin' 'em means turnin' wrenches,.....

The impeller's flow can be checked by pullin' the in-comin hose off the t-stat housin', 'n observe/ measure it's out-flow,....

 

[rotorhead511]

Thanks for the input guys.

There was no blockage but I think I'll do a visual on the shutters just to be sure. I'm ok with a wrench so this should be easy enough.

As for checking flow, I think I read at the incoming hose filling a five gal bucket in 18 seconds at 1200 RPM is good flow.

Sounds like a good plan?

Thanks again. Lesson learned.

 

[rotorhead511]

I found the flow check bulletin in the Miscellaneous Mercruiser Info link. 15 seconds at 1000rpm with quantity based on gear ratio.

 

[alldodge]

I found the flow check bulletin in the Miscellaneous Mercruiser Info link. 15 seconds at 1000rpm with quantity based on gear ratio.

Just a note, but the spec is with the boat sitting in the water, a hose cannot supply the same amount

 

[rotorhead511]

Just a note, but the spec is with the boat sitting in the water, a hose cannot supply the same amount

Thanks Dodge, saw that in bulletin. Probably has something to do with water pressure from the hose influencing flow rate.