Not sure if damage occured to motor

[Rockpainter]

Hello,

Well I committed the classic...got the gas cans mixed uop and ran my 1978 Merc -70 HP without oil for about 3 minutes on the lake until it started to smoke and I shut er down.
After I reconnected a can with Oil/gas mixute it ran but missed . Found one plug fouled..had some metal around the center and looked liked sprayed alum paint.
Changed all plugs and it started up but am not sure if I hear a noisey rocker.
Are they noisy with the cover off anyway? It is not a loud rap... just a rapid "tick".

How can I tell if I damaged the motor.

Guess I am not the first jerk to do this.....i am making the cans with"Add Oil before using".

Thanks and be kind!

 

[hkeiner]

Re: Not sure if damage occured to motor

had some metal around the center and looked liked sprayed alum paint

It does not sound good to me based upon your description above. I would suggest a compression test to get a better indication of damage to the cylinders and cylinder walls. Having good and even compression would not mean that everything else is OK, but it is an important test.

 

[j_martin]

Re: Not sure if damage occured to motor

Ain't no rockers in that one. It's a broken piston, or a wrist pin or rod bearing.

Nothing that turns that fast lives very long without oil.

Sorry
John

 

[Bigjohn1]

Re: Not sure if damage occured to motor

Good responses so far and spot-on. I will second doing the compression test and being prepared to have the powerhead rebuilt.

 

[Silvertip]

Re: Not sure if damage occured to motor

You should be able to look in the spark plug hole with a small pen light and see the top of the pistons. If one or more has lots of indentation in it (like it was sand blasted), don't damage the engine any more by running it. Get it rebuilt.

 

[jimmbo]

Re: Not sure if damage occured to motor

From lack of oil, the piston skirts and ring grooves will be the first place damage will occur with bearings being a close second. Rings, grooves, and skirts can be partially checked by pulling the tranfer covers off and looking at them thru the intake ports. Examing the bearings will require a teardown

 

[kenmyfam]

Re: Not sure if damage occured to motor

3 minutes....no lubrication....... rapid tick.
There is damage in there and to what extent is educated guesswork right now.
Will need a rebuild in my opinion and the more it is run now, the more damage will occur.
Good Luck.

 

[Scaaty]

Re: Not sure if damage occured to motor

metal around the center and looked liked sprayed alum paint.
If its like tiny little aluminum balls, its piston meltdown.
Might have holed one from heat. Start with a simple compression test..stick your thumb over the hole and crank it, and compare to the others..you'll know real quick. If seems ok, get a gauge and check...but I think the ticking is a bad piston/pin slapping back and forth

 

[Rockpainter]

Re: Not sure if damage occured to motor

Thanks for all of your advice. Now what if the ticking is just normal and it is not heard with the cowl on. I never noticed it before but I was not paranoid about the motor.

Lets say I have good compression and she runs well at all speeds. Could this also be possible?

I have one kid just getting out of College and one going into College?

I imagine a powerhead rebuild is pricey? Any guestimates?

Could I have lucked out and not messed too much up?

Thanks Again, you guys are a great help to the novice!

 

[Scaaty]

Re: Not sure if damage occured to motor

Do a comp check first...if thats good, well we can take it from there...

 

[Rockpainter]

Re: Not sure if damage occured to motor

Hey Scaaty,

Did what you said and comp is 125 on all cylynders.

Also sprayed some oil in each plug hole and looked with a penlight.
Nothing seemed scored or pitted.

Started it up and the ticking has gone away.

So, what do you think?

Would using a little richer gas/oil mixture help the motor in the future?

Thanks

 

[jimmbo]

Re: Not sure if damage occured to motor

If any thing is damaged more oil is not going to reduce/prevent more damage.
you have three choices.
1) put it in storage and never run it again
2) tear it apart, inspect it. Repairing or replacing damaged parts, if any
3) Run it as usual, taking care and watching for any unusual conditions. If something goes wrong, then you tear it down and repair/replace parts. If, after 10, 20, and 30 hrs it is still running, recheck the compression. If still good, you dodged a bullit and will have trouble sitting down because, instead of having a horseshoe up your backside you must have the entire horse.

 

[Rockpainter]

Re: Not sure if damage occured to motor

Nicely put and well thought out... You are so right.

Some of us get lucky and get the shoe and the horse...

and then there are those who have their head permanently stuck where the horse should be.

Thanks

 

[Scaaty]

Re: Not sure if damage occured to motor

Hey Scaaty,

Did what you said and comp is 125 on all cylynders.

Also sprayed some oil in each plug hole and looked with a penlight.
Nothing seemed scored or pitted.

Started it up and the ticking has gone away.

So, what do you think?

Would using a little richer gas/oil mixture help the motor in the future?

Thanks

Yep, run the SOB...beat the daylights out of it close to shore...do double oil..its 50/50 chance your OK...remember, its only a motor, and at any given time, a mess of OTHER things can go wrong...wish ya luck...!!

 

[dajohnson53]

Re: Not sure if damage occured to motor

I agree: run it close to shore, or with a kicker on board to get you back home if it fails catastrophically. Test it, don't baby it, so you know if it works, it works.

I know one man's reasonable cost is another's fortune, (especially with kids in college, I know I have one), but on the bright side, it's almost 30 years old, and good solid 15 year old engines don't cost a fortune and you'll be upgrading by a decade and a half! At the risk of being flippant and insensitive, at least it's not a new $multi thousand Etec or Honda four stroke!