Re: Lower unit compatability
Nope, other than the number of cylinders these are completely different motors and the L/U's are not compatible.
Your best bet is to find a L/U used in the same application, i.e. '800', '850', '85' '80', '75'. All of these HP ranges from '69 to arould '86 or so use the same 4-cyl 66 cubic inch powerhead with a gear ratio of 2.3:1.
Note that later-80's-models Big Threes and Big Fours have different bolt patterns to their L/U's and won't fit your motor.
L/U's from an Inline Six will also bolt up to your motor but the gear ratio is typically 2:1 and any propeller you're now using probably will be too "tall" with a Six L/U. You'd have to get a prop with approx 2" less pitch for the same performance you have now.
Check your local
www.craigslist.org as there are always lots of parts motors listed. Or eBay, but I bet you can find an entire motor on Craigslist for the price of the lower unit on eBay (plus shipping).
Any used L/U should have the gear oil checked for water/metal bits. Grab the propshaft and turn, listen for bad noises. Same with the driveshaft. Check the gearcase for cracks, especially the rear where it fits up to the prop. Salt buildup between the gearcase and bearing carrier can crack the gearcase, and the crack will just spread unless you do an ugly weld repair.
HTH & G'luck............ed
