stripped lower unit plug

[airshot]

Earlier this summer I had purchased a 15 hp johnson OB the previous owner had just replaced the water pump and changed the lower unit oil. At the end of season I wanted to change it before winter storage. The lower plug did not thread out correctly and I now see why, the housing is stripped. What are my options, do helicoils work here, can it be tapped oversize, or mabey a tapered pipe thread? Thanks in advance for any suggestions!!

Airshot

 

[boobie]

Re: stripped lower unit plug

I've always used helicoils for this repair. That way you keep the thread size orginal. Somebody on here may have a better way tho'.

 

[kbait]

Re: stripped lower unit plug

I'd first call Tim's outboard with your model number. 218-682-2331. If they have a used one, it'll likely be cheaper than even the heli-coil route. May as well put a new head gasket on while your there. If they ship to me before 3pm, I get it the next day!

 

[ovnic1234]

Re: stripped lower unit plug

I paid a local automotive repair shop $35 to put in an threaded insert. I don't know if that is an average price for that kind of work. Just giving an option and approximate cost. There's always a cheaper way.

 

[AlTn]

Re: stripped lower unit plug

isn't this a stripped lu plug?...not a stripped sparkplug hole?...is there enough thread left to chase it with a tap?

 

[kbait]

Re: stripped lower unit plug

Sorry.. I thought you meant spark plug hole. I'd try to chase it with a tap (stated above).. if there's nothing left, may as well try to tap it larger, and rig a new plug.. Otherwise it's changing out the case, and that'd be a much larger job..

 

[boobie]

Re: stripped lower unit plug

I'll still stick with my helicoils. That way orginal drain plugs and washers can be used.

 

[Sixmark]

Re: stripped lower unit plug

Yeah helicoil is the way to go if you ask me.

 

[rodbolt]

Re: stripped lower unit plug

yeaaaaaaa
but
they dont make a heli coil the size you need.
the thread pitch is right, the length is long.
this is what kills me on the net, the amount of info from folks that never did it nor tried it.
can it be heli-coiled?
yes
very easily.
but
but but.
you MUST modify the standard coil AND you MUST use the plug that uses the plastic washer.
note the language, I did not say use the plastic washer.
I said USE the plug that uses the plastic washer, and the plastic washer.
the oring style plug leaks with a helicoil as does the paper washer plug.
carefully grease the helicoil tap.
carefully tap that hole.
carefully us a good sharp set of dikes to cut about 2-3 coils off the heli-coil insert.
carefully break off and RETRIEVE the drive tang.
now your good to go.
just remember, 3 types of plugs have been used by OMC/BRP.
one has a flat surface,takes a paper gasket.
one has a face groove, takes an Oring.
one has a face ripple, uses a plastic gasket.

 

[boobie]

Re: stripped lower unit plug

Rodbolt, sounds like you don't like helicoils. Tell us, what do you use ? I've used them for the last 45 yrs and if installed correctly you don't have to worry about the paper gaskets or orings leaking.

 

[metriccrescentwrench]

Re: stripped lower unit plug

Rodbolt, sounds like you don't like helicoils. Tell us, what do you use ?

The point was that the standard helicoil is too long and needs to be slightly modified, that's fairly thin metal around the lower unit drain plug.

 

[boobie]

Re: stripped lower unit plug

I know about the helicoil being too long and that's why I have a good sharp pair of dikes.

 

[Sixmark]

Re: stripped lower unit plug

We were granting the OP the benefit of the doubt that he would see the difference in lengths, last time I checked, even helicoil promoted their product as being usable with multiple applications with some customization.

Are we now going to start requiring step by step procedures with photos for every subject that is posted on here, oh and are we going to be required to post our phone numbers for 24hr service?

If this is what people are going to start having to deal with for offering help, then what is the point of helping in the first place. I guess we should start telling every poster on here "Look it up in the service manual"

 

[boobie]

Re: stripped lower unit plug

Six, I agree with you on the above and would really like to elaborate on it but I'd most likely get in trouble for it. Only thing I'll say is I've delt with a lot of people in this here marine business over the years and sometimes they just don't want to LISTEN !!

 

[lmuss53]

Re: stripped lower unit plug

Personally I would clean everything up and run the plug back in, it was sealing before wasn't it?

If you have to fix it and don't want to go the helicoil route, use a 1/8 NPT tap and a brass plug. If you want to get real fancy use the allen wrench type plug that resembles a set screw. The tap drill is a letter Q drill at .332.

 

[MTboatguy]

Re: stripped lower unit plug

This may sound weird to some, but I had an old 35 Johnson back in the eighties that I actually fixed a lower unit drain hole with , JB weld, I mixed a good batch up, coated the bolt with Vaseline, coated the bolt with JB and screwed it in then let it set overnight, back it out the next day, cleaned everything up, inside and out, then reassembled and it is still going strong with no leaks(My Dad has it now)

Was that the right way to go? Probably not, but at the time, I couldn't think anything else up, did it work? For me it did, and it has been going for over 25 years now..go figure..

 

[airshot]

Re: stripped lower unit plug

To all that responded, many thanks!! I have no problem with detailed instructions or any other ideas. Just appreciate the feedback........

Airshot