Lower unit fill plug stripped

New to me 1970 Evinrude 60hp. I filled the lower unit with correct oil and tried to put in plug with new nylon washer and it would not thread in. I drained the unit and removed the nylon washer and the plug threaded in. How do i solve this conundrum? I thought about maybe a helicoil but I don't know where I would find one in my area? Also what size helicoil?
Any info is good thanks.

Re: Lower unit fill plug stripped

Are the threads really damaged, or is the new washer just too thick for the motor? I'd be inclined to look for suitable substitute washers before I'd go helicoiling. Maybe a rubber o-ring.

But if that's what you decide to do, I highly recommend finding an old-school hardware store, the kind with old men who know what you need to do and will make sure you know how before you leave the store. Not the teenaged autoparts store manager. Take the screw with ya, they'll fix you up.

Re: Lower unit fill plug stripped

jtexas said:

Are the threads really damaged, or is the new washer just too thick for the motor? I'd be inclined to look for suitable substitute washers before I'd go helicoiling. Maybe a rubber o-ring.

But if that's what you decide to do, I highly recommend finding an old-school hardware store, the kind with old men who know what you need to do and will make sure you know how before you leave the store. Not the teenaged autoparts store manager. Take the screw with ya, they'll fix you up.

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It was threaded in fine when I got the motor. I just found out that a helicoil kit will set me back 100 odd bucks which is way out of budget right now. I was thinking of maybe getting a bolt that is just 1/4" longer thread to catch the threads that are not damaged. If its a hex bold I can grind the head down a bit so it doesn't stick out as much. I'm hoping this works. The threads on the plug are just too short to catch so it should. I read an o ring would not be that good from people who have posted here in previous posts.

Re: Lower unit fill plug stripped

If the plug threaded in without the washer then you must have the wrong washer or you're doing something wrong. Maybe there was more than one washer and you only removed one. If it was stripped I would think the plug would have rattled loose and fallen out.
I don't like the thought of a bolt in there with gears moving around and back and forth.

Re: Lower unit fill plug stripped

Evinrude Boater said:

If the plug threaded in without the washer then you must have the wrong washer or you're doing something wrong. Maybe there was more than one washer and you only removed one. If it was stripped I would think the plug would have rattled loose and fallen out.
I don't like the thought of a bolt in there with gears moving around and back and forth.

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The bolt will be shorter than the plug right now. The plug has 3/8 to 1/2 of thread on it and the rest is magnet. I will custom cut the bolt and magnetize it before putting it in. I have some confidence in this but we'll see.

Re: Lower unit fill plug stripped

60-80 in lbs torque. Don't go leaning on the wrench. The plugs are put in with a screwdriver and that's plenty tight.

Re: Lower unit fill plug stripped

Evinrude Boater said:

60-80 in lbs torque. Don't go leaning on the wrench. The plugs are put in with a screwdriver and that's plenty tight.

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agree...if you're not crushing 'em, they can be reused. Course, you don't know they're shot until you find water.

Re: Lower unit fill plug stripped

Quick question to add here: I was told by my local Johnson dealer that he can't get me the washers. Are they a 'standard' size and material? I'm holding off on taking mine out until I know what my options are in case I find mine to be bad

Re: Lower unit fill plug stripped

tnltracy said:

Quick question to add here: I was told by my local Johnson dealer that he can't get me the washers. Are they a 'standard' size and material? I'm holding off on taking mine out until I know what my options are in case I find mine to be bad

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marineengine.com frequently has little pieces parts like this. On small packages, shipping eats you up. But you can get omc gasket sealant & moly lube and that 3m substitute for OMC adhesive M, makes it a little more worthwhile.

Wonder what your dealer's putting into his customers' motors?

In a pinch, I'd take 'em to the hardware store & try to match 'em up. Should be able to find a suitable substitute based on your knowledge of the application. Make it highest quality though, since a total failure could be catastrophic.

Re: Lower unit fill plug stripped

Well I got a bolt last night and made the head round not hex as it would not fit in the recess. Then I cut a slot sutable for my screwdriver and tested it with an o-ring as this is all I could get my hands on. Nearest marina is 50km away and closed by the time I get out of work. So it worked.
I Magnetised it and filled the lower unit with correct oil and from the bottom hole as in the manual. Put the bolt in and placed a clean sheet of cardboard below to check for a leak. Then I went to bed and to work today with out getting back out to check on it.
I'll see in about an hour & halve whether it leaks. I did catch the threads and tighten down good so it should be well sealed. If it is good I will put it in a barrel and run it for a while and then check the oil for water. I did every other seal on the lower unit when I had it off to do the pump impeller so if it lets in water this is the propable cause.

Re: Lower unit fill plug stripped

rayodunne said:

Well I got a bolt last night

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regular bolts will rust.

Re: Lower unit fill plug stripped

It gets cold in Spencerville and the case can crack if water is in the oil. Mine did and it was hard to find the cracks without pressure testing in a tub of water.

Re: Lower unit fill plug stripped

CBINMN said:

regular bolts will rust.

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I plan on getting a stainless bolt today and duplicate the one I made so when I do my first oil check after putting it in the barrel I can swap them. I am going to fastener store to see if I can get a stainless machine screw which would be closer to the original plug.

Evinrude Boater said:

It gets cold in Spencerville and the case can crack if water is in the oil. Mine did and it was hard to find the cracks without pressure testing in a tub of water.

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I can prevent that from happening by filling with fresh oil before the frost comes, from what I have read on the forum. I have no history on this motor so for all I know it could have a frost crack in there already. I'm just starting out and if water enters the lower unit further tests will be conducted.
I have found out my neighbor has access to helicoils of the right size at his workplace so if this fix doesn't do it I will take him up on his offer.
Thanks everyone for there responses.