Logo
FULL SITE MENU

Engine Swap140 hp Merc to replace 85 hp Johnson

G

gfbracht

Guest
"Hi. I've written for sug

"Hi. I've written for suggestions/information about the "seize issue" with my `76 Johnson outboard. It is mounted on a `73 Chrysler 20' Cuddy Cabin boat.

I have an opportunity to purchase the 140 hp Merc outboard at a reasonable price. It supposedly has "0" hrs. after a complete rebuild. It also is stated to have a brand new water pump. It is a `78.

Does anyone know what challanges, if any, I should look forward to in this potential swap? Like electrical?, various wiring?, steering?, etc.

I appreciate any insight into this matter before I commit to the purchase/swap.

I await any/all responses.

Thanx in advance,
Glenn"
 
The mercury should come with i

The mercury should come with its own control box and wiring.Plug the holes in the transom and away you go.
 
Thanx! Sounds pretty straight

Thanx! Sounds pretty straight forward. What is the best material/procedure to plug the old holes in the transom?

Do you think I'll have to "jerry rig" the throttle control or the shift mechanism?

I await further input.

Thanx again.

Glenn
 
The Mercury should come with i

The Mercury should come with its own controls.The JOHNSON controls do not fit and it is not worth the effort to make them fit.Plug the holes with 1/2" hardwood dowels and epoxy.
 
"Great insight, THANX ;-)

"Great insight, THANX ;-)

The Merc does come w/ its own controls. I will actually purchase the boat w/ the engine installed. I will then (theoretically) proceed to remove both engines and controls and basically swap them out complete.

Fill the old mounting holes and epoxy. Drill new holes and install.

Sound correct?

Thanx,
Glenn"
 
"Glenn,

If the Merc. bolts

"Glenn,

If the Merc. bolts up using 1/2" bolts (as opposed to screw clamps) the bolt pattern is the same and no hole filling is necessary.

Are you sure the year is right? 140 doesn't ring any bells with me in that year for Merc. are you sure it's not a 150?

Any Merc. guys with any insight?"
 
"Hi again. I'm not totally

"Hi again. I'm not totally sure of the year of this engine as I have not yet purchased it. I am operating on second hand info, but I was informed that the BOAT is a `78...maybe the engine is not.

It would be sweet if the Merc engine would just bolt onto the existing holes from the Johnson engine.

I'm not sure about weight differences between the two engines. I hope there is not a significant consequence for a substantial weight difference.

I will attempt to upload some pics of the Merc engine...maybe someone can determine the year.

Bad news...I attempted to upload pics, however, they exceed the maximum kilobite allowed.

Thanx,
Glenn"
 
"I'll try to upload pic...

"I'll try to upload pic...
14080.jpg
140 hp Merc Outboard
 
"gfbrach,

Good work posting

"gfbrach,

Good work posting the picture! But that's pretty small.... you could try the 400 x 400 pixel size."
 
"Okay, I finally picked up the

"Okay, I finally picked up the Merc Engine (w/ boat). The serial # is:5092579...so, I'm assuming it's a `79? Who knows??

I await your valued response(s).

Thanx again...
Glenn"
 
For Mercury 140HP that serial

For Mercury 140HP that serial number would be 1978.

It is not the last two digits of the serial number that matters.

1978 140HP was serial number starting 4865678. 1979 starting was 5189788.
 
"Thanx for the updated info.,

"Thanx for the updated info., Andrew. Merry Christmas, Happy New Year, & Seasons Greetings.

Thanx,
Glenn"
 
Back
Top