Harpoon

I have a friend with an older Mako and a late 80's 90hp Johnson that is in great running condition.

THE ISSUE..... the drain plug/screw on the lower unit is siezed. You can tell its been a problem by the way the slot on the screw is all beat up.

I'm looking for a "trick" to get this loose without causing more damage. Otherwise we are just going to TOP OFF the oil and let her go...

If you have a trick you can share that would be great.

Regards,
Capt Phil

eb1326

It happens to my Merc every year...i take a large Flat scredriver or a properly-sized chisel and bang it a couple times with a hammer it loosens the screw up and I can then turn it.....works everytime.

__________________
2008 Sea Hunt 240 F250
1971 17' Mako 90hp Merc
www.fly-mag.com

eb1326

double post sorry

__________________
2008 Sea Hunt 240 F250
1971 17' Mako 90hp Merc
www.fly-mag.com

A1 Outboard

If it has been in saltwater usually you can see a thin line of salt buildup around the circumference of the screw head. Use a dental pick (explorer) to scrape away the crud as deep as you can go. Warm the area around the screw with a propane torch using a circular motion around the screw.

Then use an impact driver with a wide screwdriver bit on it, close to the width of the screw slot, and give the driver a firm hit while holding a counterclockwise twist on it. Normally one or two "taps" is all that is needed to break it free.

Now if the problem is a burr on the screw and/or damaged threads inside the gearcase, then you may be in for some work or professional help. In severe cases let a machine shop drill out the drain screw and retap the threads.

Good luck.
Mr. Bee

Harpoon

Thanks Mr. B

Tha motor used to sit on tidal flats.... so there may be some crap binding it up. I was concerned about the impact driver harming the casting.