Outboard - Drain plug will not unscrew

[Finallybuyingaboat]

Okay, I almost have my barge ready to have a mast attached. I got the boat into the water today and it didn't sink! I have done major work on this mess over the past 7 months and still did not know if it would sink or float until today, so I am extremely relieved! I'll post some pictures tonight or tomorrow night.

Anyway, I need to replace the gear lube on the lower housing of my outboard, but I cannot get either the vent plug or the drain plug to turn at all. I do not want to strip the srcew heads, so once again I have come here for some ideas...it is an 8 HP evinrude yachtwin long shaft motor. So far, I have just been trying to turn it with a large flat head screwdriver, but it accomplishes nothing.

I bought the motor second hand, so have no idea when the lube/gearcase oil was last changed, so I figure I should do it just to be safe. It should be changed every year anyway.

[lbdavis]

I've had a tough time with lower unit screws in the past and I always got them with the largest flat head screwdriver I could find and a second person on the opposite side of the lower unit. This way I could apply my full force down (or in this case, sideways ) onto the screw head without trying to break the engine free off the motor mount.

Be sure your helper is safe from impalement from said screwdriver!

[pfatyol]

Do you have an impact driver?

I have had luck with PB blaster then using the impact driver.

[TrueBlue]

This may sound archaic, but have you ever tried using a screwdriver bit in a bit & brace? These tools may have been ignored during the past decades, but I still find uses for them every now and then.

You can apply more downward pressure because of the ball-bearing palm knob on axis with the screw, reducing the possibility of stripping a screwhead while maintaining increased torque.

[TrueBlue]

I would caution you against using an impact driver against the thin aluminum casing of your outboard's lower unit. These tools require a heavy blow in order to work effectively - with risk of cracking the casting.

[timebandit]

Do yourself a favor and use a properly sized and dressed screwdriver.

You might try turning it in a tightening motion first.

Screwdrivers of the proper size usually have a square shank so you can use a Cresent wrench on them. Try to keep the wrench as close to the bit as you can.

I also advise against the impact screwdriver.

If you ruin the slot and mangle the plug beyoud all repair it is time to use the Small hammer and punch.

Rick

[Finallybuyingaboat]

I'll go fo rthe biggest screwdriver I can fit in , and if that does not work I will try and find an old manual drill as trueblue put forth.

[SVDistantStar]

I do small outboard repair and when i have plugs that wont move ive got a special screw driver. Its a large flathead thats been ground down a bit to not be as pointed. It has a square shaft so i can get a wrench on it. I lay the motor on the ground with the plugs up, spray them with either PB Blaster or Seafoam spray. I then push as hard as i can on the screw driver wile turning the wrench. It works about 99.9% of the time. If it doesnt work, ill pull the lower unit apart and soak the whole thing in a bucket of WD-40.