any outboard mechanics or a service

BillS

BillS

Well-known member
manual that covers a 1988 4hp Mercury. I had to replace an impeller but I am having a problems getting the lower unit back mounted to the motor. I got it line up and in twice, but couldn't get the shift linkage adjusted right. Pulled it back out and now I can't get in line back up. I am not sure if there is a certain procedure to get in and adjusted right. Thanks

bill
 
Have tried Forward Neutral and reverse. I can't remember which it was in when I was able to get things lined up. Also tried all three when trying to adjust linkeage, with no avail.
 
Take a pair of plier and turn the shift shaft on the lower unit and turn it clockwise. While turning it, spin the prop until you feel it go into gear (forward). Make sure the motor is in forward, then slide back in. You need to make sure the driveshaft, shift shaft and water tube are lined up. For future reference make sure it's in forward before taking it apart.

Kevin
 
Thanks I will try that, the only thing is this motor shift shaft is a two part deal. A rod comes down from the motor and a rod come up from lower unit. there is a flat linkage with a bolt where the top one meets the lower rod. The top of the lower unit rod goes in a hole in the houseing, it is also bent(factory). When I did get it in I couldn't get the linkage aligned right, but this time I will leave in forward and try.

Thanks again
 
worked....but I have to put in neutral to tighten shift linkage bolt. When I do, it clicks into reverse, but not really in forward. How do you adjust it? also where that shift bar comes through the housing in forward it doesn't hit the plate above it. Is it bent the wrong way? Thank you so much already.....
 
Bill,

Not really sure on that one. We work on a lot of smaller motors, but not many below a 9.9. That sounds like a diferent Mercury system on your 4hp than that of ones we work one. I wish I could be of more help.

Kevin
 
There shouldn't be any adjustments needed to reconnect the linkages. Are you sure it's all the way up and flush? I just did a water pump on a 7.5 mariner and it gave me a few fits, but finally went back together. Some pics might be helpful to see exactly the problem.

dc
 
ok, first pic is where the shift shaft from bottom meets the shaft coming down from motor. when I say adjust, I mean lowering the lower unit, then tighten, vs tighten when the unit is all the way up. Second pic is where the shift shaft from lower unit comes through s hole in housing, this pic is when the motor is in reverse. Last pic is when motor is in forwsrd. It may have been like this before I don't know. I do rem without taking it lower unit off I can't get a pic of the shaft, the shaft has a wave, where it bends one direction for 2" then straightens back out. at rest the shift shaft would rotate 180 degrees, if you lift up it would rotate 360 degrees, in the lower unit. Thanks again guys

linkage
View attachment 021.JPG


Reverse
View attachment 024.JPG

Forward
View attachment 025.JPG
 
The shift rod should be bent as you described. If I'm not mistaken, that rod will rotate all the way around to allow the rod to clear the housing obstacles. Ensure that the rod is in the correct position when you install the lower unit. In other words, the rod has the ability for the top of the rod to either be close to the front face of the lower unit or the back of the lower unit depending on how it is rotated. It should only be able to feed up thru the motor housing in one position. Ensure that there are no gaps between the housing and the motor once it is fully installed. I would probably drop the unit out again. I would inspect inside the housing with a strong flashlight looking for any "keyway" tupe grooves on the drive shaft to ensure I am aligned correctly and that there is nothing blocking my way. install the lower unit far enough to get one bolt started and then see if there is anything you can do with the shift shaft. If I remember right, I had to shift my friends one way or the other so that I had enough shift rod to install the clamp that goes to both shift rods.



dc
 
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