Merc 65hp leg to fit 85hp?

[sillydilly]

Hey guys, I have a Mercury 85hp outboard and I hit a bunch of rocks due to a wind storm and ended up getting a serious grinding noise in the lower unit. I was able to limp it back to the trailer with a very bad grinding noise, but now it has trouble even turning over the engine because something is ceasing down there.

I ended up finding a local classified for a 65hp with a blown motor, and Im wondering if I could buy it and bolt it on to the 85hp and be on my merry way? unless theres a nother solution to fixing my lower unit?

the 65hp parts unit it cheap enough to go pick up and give it a whirl, but I thought id check with some experts first. I dont know the years yet but I will post a picture as soon as I can

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

here are photos of my 85HP

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

and here are the photos of the 65hp for sale

thanks in advance for any help!

 

[Faztbullet]

Re: Merc 65hp leg to fit 85hp?

Sorry but it will not fit as its a 3 clylinder if it was a 4 cylinder 650 it would be a direct fit

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

so I cant even tear them apart and replace whatevers broken inside?

 

[Chris1956]

Re: Merc 65hp leg to fit 85hp?

Silly, 4/6 cylinder gearcases interchange, however, you likely have a 2.3::1 gear ration and the IL6 gearcases will be 2::1. A prop change may be necessary.

Where are you located?

 

[chum1]

Re: Merc 65hp leg to fit 85hp?

Sorry but it will not fit as its a 3 clylinder if it was a 4 cylinder 650 it would be a direct fit

I am fairly certain that a 69' 4 cyl 650 will not fit the 76'/77' 850's as the length dimensions fore and aft at top flange are different......I might have got ya Fazt

What has probably happened is the shaft bent and it can be straightened at a machine shop if not to far gone. Those shafts new are about 300 bills, the shaft in the 650 may work though?....if thats the prob.

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

im located in southern Alberta.

I might pull the leg apart later and see whats going on in there. I got the entire boat cheap enough I can afford to probably just sell it all as is with a busted leg and get back what I got into it, I just figured it'd be nice to get it back in the water for a nice little runabout.

if I get around to wrenchin it apart Ill take lots of pics, just for the hell of it

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

anybody have any tips for doing this?

I heard a lower unit can be as complicated as taking a car tranny apart. The only thing is, I dont have much to lose so it doesnt really hurt to start snoopin around and maybe learn a thing or two while Im in there

 

[chum1]

Re: Merc 65hp leg to fit 85hp?

http://forums.iboats.com/showthread.php?t=391064

there you go, a maint manual would be good, there are quite a few threads on this subject also

 

[Faztbullet]

Re: Merc 65hp leg to fit 85hp?

I am fairly certain that a 69' 4 cyl 650 will not fit the 76'/77' 850's as the length dimensions fore and aft at top flange are different......I might have got ya Fazt

I'll have to check a 1969 model but I know a 1970 and up will work as done it numerous times as the housings are the same
for the 650,800,115,125 and 135....

Silly, 4/6 cylinder gearcases interchange, however, you likely have a 2.3::1 gear ration and the IL6 gearcases will be 2::1. A prop change may be necessary.

They will bolt up but the 2:1 ratio makes a it a dog on low end..........

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

ok, well i dropped what I believe to be the lower unit, and Im kinda not sure where to go from here. what do you guys figure?

Shot at 2012-09-10

 

[chum1]

Re: Merc 65hp leg to fit 85hp?

ok, well i dropped what I believe to be the lower unit......

um....yea

might as well try to remove prop shaft and check innards, if there good, repair whats needed, reseal,replace impeller and reinstall. that shaft looks like its rusted? I thought the driveshafts fr mid 70's were stainless, you may have a different lower end then original.

If these engines are put together right they will pull a 300lb+ fatman on a tube up to plane guaranteed providing you hav good compression and its rigged correctly

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

how do I remove the prop shaft and check innards? I believe you're supposed to uncrew the big inner nut thing then use a slide hammer to pull everything out? am I on the right track?

I know a need a special tool the unscrew that giant nut but I can make shift something else.

 

[Chris1956]

Re: Merc 65hp leg to fit 85hp?

There is a stainless retainer that locks the donut-shaped cover nut in place. You need to bend the locking tabs out of the way. The cover nut is supposed to unscrew, but lots of times the threads are corroded off. The bearing carrier comes out with a slide hammer. Then the fun begins.....

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

I got the locking tab, I believe there's only one?

if I can't get the nut unscrewed Im gunna put it back together. It seems like this leg can be saved, almost as if there's a bearing or something in there thats wrecked, because sometimes it will spin the prop shaft and other times it will get stuck... who knows..

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

got it unscrewed, but now Im still confused. slide hammer the rest off? been lubing it and pounding at it for awhile now, gunna keep trying i guess, any tips?

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

for anyone interested, these are the damages.

 

[Faztbullet]

Re: Merc 65hp leg to fit 85hp?

Find a good used one(2:3:1 ratio) and reseal and istall new impeller and yer good to go...

 

[sillydilly]

Re: Merc 65hp leg to fit 85hp?

Ill keep my eyes open for something that will fit