knocking the dust off an old 3.9 merc. Need Parts?

[huntxtrm]

I have and old 3.9 merc. I am trying to fix it up for a small river boat. It has potential. But I cant' find any parts by serial number? Can anybody help? I think its around a mid 60's model. I want to put in a new impeller, and rebuild the carb. It is also missing the drain and fill plugs on the lower unit.

 

[MTboatguy]

What is the serial number on it? Often times on the older motors the only place you can find parts is on ebay, ends up a lot of NOS parts get sold on there. But post the serial number up and we can figure out what year it is.

 

[huntxtrm]

2377882 is the SN. I can take a pic of the motor if needed.

 

[huntxtrm]

I found some parts? But not all. www.oldmercs.com. Anybody ever deal with them?

 

[MTboatguy]

Looks like it is a 1968, so you need to start your search there, I boats looks like they carry the impeller for this motor:


http://www.iboats.com/Mercury-Water-...view_id.271499

It is a Sierra part number 18-3447 if they don't have it in stock

The lower unit drain screw is Sierra 18-2244

If you want to do a complete lower unit seal kit, the Sierra part number is 18-2628

Iboats is also listing the carb kit for this motor:

http://www.iboats.com/Mercury-Carburetor-Kits/dm/view_id.271586

If they don't have it in stock, it is a Sierra 18-7013

That is what I was able to find with a short amount of searching.

 

[huntxtrm]

Thanks! That will help a lot! I do appreciate it.

 

[emckelvy]

You'll find parts breakdowns for your motor here:

www.marineengine. com

Just copy into your browser and remove the space (this site parses competitor's addresses).

HTH.........ed

 

[huntxtrm]

No Title

I want to take this lower unit down. How do I get it out. I just want to make sure all is good, if i'm going to spend some time and money on this little jewel.

 

[huntxtrm]

That inside nut thing seems stuck. It is left hand threads right? I will try and make me a tool tomorrow. Maybe I'll have better luck.

 

[racerone]

Left hand is correct.

 

[huntxtrm]

No Title

Ok, got it apart. Drive shaft is pitted at seal areas. I did see a thread on here somewhere,, someone suggested putting a sleeve on one? Any ideas? could I just weld it up, and grind it back off? Probably not?

 

[MTboatguy]

You could weld it up and then machine it off, I know the machine shop my Dad used to work for, did this quite often, but I would not weld up and then grind off, you will never attain the true round that you would need and you would end up with an unbalanced shaft. You should be able to find one on ebay that won't be that expensive.

 

[iggyw1]

I have and old 3.9 merc. I am trying to fix it up for a small river boat. It has potential. But I cant' find any parts by serial number? Can anybody help? I think its around a mid 60's model. I want to put in a new impeller, and rebuild the carb. It is also missing the drain and fill plugs on the lower unit.

BEWARE when putting it back together!! The fuel pump cover has a short and a long screw in it. DO NOT MIX THEM UP!! I have the same motor and I did mix the two screws up. When I put the short one where the long one goes, I cracked the mounting "ear" off of the cover. It is obsolete. I found one for like $80. Do not make the same mistake that I made. It is an excellent little motor.

 

[huntxtrm]

Thanks for the great info guys. Is there a part number that will interchange? I noticed a thread where someone put a stainless shaft out of a new engine. Danged if I can find the thread again.

 

[huntxtrm]

Oh, and I busted that dang inside retainer on the prop shaft. I got to find one of those now.

 

[huntxtrm]

I'm going to have to get this drive shaft repaired at a machine shop. People on ebay have lost their mind! LOL I'm not spending more to fix one, than I can buy one for.

 

[huntxtrm]

Motor that is. Shafts are crazy expensive.