Lower Unit for 1965 Evinrude 18HP

I just acquired a Evinrude 18hp with a bad forward gear and clutch dog. The previous owner pulled it apart so I am also missing the pinion gear thrust bearing and both forward and reverse thrust bearings.

I only have 2 questions to start with.....

What other model year and horse power Evinrudes have the same lower unit, or one that will bolt up or use the same internal parts?

Can anyone direct me to a used part house that I could try other than TC outboard?


Thanks
Kevin

Re: Lower Unit for 1965 Evinrude 18HP

That basic lower unit was used for many years, from about 1955, up into the '80s, on the 18-20-25hp 22 cu in motors. That's not to guarantee that all the internal parts are the same. Looking up the part numbers will verify yes or no.

Re: Lower Unit for 1965 Evinrude 18HP

OMC web site only goes back to 1968. Do you know of a web site that shows prior to 1968 Evinrude/Johnson diagrams and part numbers?

Re: Lower Unit for 1965 Evinrude 18HP

I can tell you this: I just checked the books for the '63 and '68 and they are the same, so your '65 surely would also be the same as the '68. Same that is except for they did an un-nose job on the case somewhere in those years (straightened the leading edge), but that makes no significant difference.

Then I went back to '59 and found some different part numbers for the gears. But I'm confident that the whole thing as a complete unit would bolt up and work.

Re: Lower Unit for 1965 Evinrude 18HP

Try laingsoutboards.com. Rick

Re: Lower Unit for 1965 Evinrude 18HP

I am looking at a gear set that the seller states has the following numbers -
#s found on 387209, 320800, & on the cradle looks like 303731

Could you please check and see if they will work? all help is much appreciated.

Re: Lower Unit for 1965 Evinrude 18HP

Re: Lower Unit for 1965 Evinrude 18HP

K Hultgre said:

I am looking at a gear set that the seller states has the following numbers -
#s found on 387209, 320800, & on the cradle looks like 303731

Could you please check and see if they will work? all help is much appreciated.

Click to expand...

Sorry, I have nothing crossing to those numbers. BTW, 303731 is a reed stop, not a cradle

Re: Lower Unit for 1965 Evinrude 18HP

And 387209 is a forward gear from a late 1970's 6HP motor. Checking 320800, that's late 70's 6HP as well, but reverse gear.

Re: Lower Unit for 1965 Evinrude 18HP

Thanks for the great help, I'm sure I'll be back with more questions before this one is done.

Re: Lower Unit for 1965 Evinrude 18HP

Can anyone tell me if the lower unit complete and or gear set from a Evinrude Fasttwin 15hp model 15012 will fit the 65' 18hp ?

Re: Lower Unit for 1965 Evinrude 18HP

One easy way to tell is if the case has a 5 bolt pattern such as your case has. F R pointed out the difference in the 20, 25 HP case, another difference is that the 25 case is much thicker in cross section, making for a much stronger casting. One thing to look out for when changing the case is to check, and see if it is bent, I found this to be quite a common problem wwith the 15, and 18 case, as they are quite thin through the lower web. This will cause undo strain on the drive shaft, and lower pinion gear bushing. With the case apart, you can set it up on a flat surface such as a drill press table with a pointer, or dial indicator in the chuck. With the case upside down on the table, you measure to see if the two surface's are parallel. The maximum tolerance is .030. We once bent the case on our 18. I measured 3, or 4 cases' before I found one in tolerance, none were truly straight. We have 2 l8 HP engines, I put 25 cases' on both. Our local river can be very shallow, that is it can be until a couple of week's ago, when it went 12 ft. above the all time record 40 miles down stream from us. It can give a engine quite a beating if you are not careful.