Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1

TOPIC: 1969 Merc 650 Red Band - lower unit interchange

1969 Merc 650 Red Band - lower unit interchange 1 year 5 months ago #128760

Hi,

The lower unit on my 1969 Mercury 650 Red Band has a small hole from an impact from previous owner. Ideally I'd like to replace the lower unit: What models interchange with mine? There are plenty up here around Toronto Ontario, I just need to know which one to pick up.

Please Log in to join the conversation.

Re:1969 Merc 650 Red Band - lower unit interchange 1 year 5 months ago #128762

most 650 1965 and up and 6cyl also fit just make sure they are the same gear ratio.

Please Log in to join the conversation.

Re: 1969 Merc 650 Red Band - lower unit interchange 1 year 5 months ago #128768

  • ed-mc
  • ed-mc's Avatar
  • Offline
  • Gold Boarder
  • Gold Boarder
  • Posts: 997
  • Karma: 217
  • Thank you received: 25
Both 800-4 and 850-4 (along with the later 80hp and 75hp variants) will bolt right up and have the same 2.3:1 gear ratio. I can't recall for sure if yours has the 2.3:1 but I did have a '71 with that ratio and they run very well with those gears.

Craigslist is your friend for spare parts!

Last thought, if the hole isn't in the oil-containing parts of the gearcase, you could have it weld-repaired then repaint.

HTH & G'luck with the replacement.............ed

Please Log in to join the conversation.

Re:1969 Merc 650 Red Band - lower unit interchange 1 year 5 months ago #128776

Hi,

An original 1969 Merc 650 lower unit would have the 2 to 1 ratio. The swap to the later 2.3 to 1 as Ed mention is nice, but a change of the propeller will also then likely be required.

Regards,
Joe
www.fergusonpoolemarine.com
This email address is being protected from spambots. You need JavaScript enabled to view it.

Please Log in to join the conversation.

Profile Picture:
E. Carl Kiekhaefer (Mercury Founder) & Joe Poole Sr. @ 1964 Mercury Dealer Meeting

Re:1969 Merc 650 Red Band - lower unit interchange 1 year 5 months ago #128795

I think the previous owner had JB weld or something wedged in there and it just came out. The benefit of a new lower unit for me is I get a new skeg, as the one on there right now is really beat up.

I'll look around for the similar year units.

What ratio would I need for the propeller?

Please Log in to join the conversation.

Re:1969 Merc 650 Red Band - lower unit interchange 1 year 5 months ago #128799

I think the previous owner had JB weld or something wedged in there and it just came out. The benefit of a new lower unit for me is I get a new skeg, as the one on there right now is really beat up.

I'll look around for the similar year units.

What ratio would I need for the propeller?

Please Log in to join the conversation.

Re:1969 Merc 650 Red Band - lower unit interchange 1 year 5 months ago #128808

just turn the drive shaft 1 turn and count the turns on the prop shaft. if 1 turn each it is 1-1. if not it will be 2.3-1

Please Log in to join the conversation.

Re:1969 Merc 650 Red Band - lower unit interchange 1 year 4 months ago #129034

Found a decently priced 1979 70HP lower unit. I'm assuming it's compatible, just have to figure out the ratio and prop pitch?

Please Log in to join the conversation.

Re:1969 Merc 650 Red Band - lower unit interchange 1 year 4 months ago #129035

70 hp will not work. They are based not he 4 cylinder and 3 cylinder motors. . You need a big 4 or 6 cylinder lower unit.

Please Log in to join the conversation.

Re:1969 Merc 650 Red Band - lower unit interchange 1 year 4 months ago #129037

Dave B wrote:
"just turn the drive shaft 1 turn and count the turns on the prop shaft. if 1 turn each it is 1-1. if not it will be 2.3-1"

And if you turn the driveshaft two complete revolutions to one for the prop shaft,...You have a 2:1 ratio.

The other thing you need to know is if you have a short shaft (15") or long shaft (20").

Please Log in to join the conversation.

  • Page:
  • 1
Time to create page: 0.137 seconds

FG Login

Donate

Please consider supporting our efforts.

Glassified Ads

Completely Restpred Redfish
( / Boats)

Completely Restpred Redfish
04-19-2018

FiberGoogle

Quick Search

Who's Online

We have 2454 guests and 8 members online