taking bottom off 150hp Merc

[Dignity]

need to take the bottom of off my 150hp merc outboard as I fugure it might be easier than dragging the whole boat out to take to the mechanics. #I can see 3 bolts up the front and the 1 at the back which also holds the anode in place. #I gather once these are undone there will be more to undo once the leg is separated eg the forward/reverse gears. #any traps for the unwary. #Should the gears be in neutral etc. thnx in advance for any help


sam

edit: found 2 more nuts under the rear fin - mmm, where do I go from here?

[Dignity]

I loosened all the nuts till they were still half on the bolts which gave about half inch of play. Couldn't get the bottom part to move at all. I know that the shaft has a splined end but how much force is required to move it or am I missing something. The bottom was off in February as the impeller was replaced as part of the service. I took the bottom an 85 hp off back in 1982 and from memory it wasn't that difficult, or was it.

sam

[mark221263]

Hi there, your pretty much onto it. There is a total of six botls/nuts and you've found them all.
There is also a small plastic tube at te front of the leg with a small barbed joner that feds water pressure tot he speedo (if you have one).
I leave the leg in nutral and undo all of them totally apart fromt he 2 nuts at the sides of the leg which I undo progressively to slowy let the leg come away.
If it hasn't been off for a while undo them a few turns and use a rubber allet to give the lower leg a few taps.
Apart from copying I guess the manual would say something like,

1. Disconnect high tension leads from spark plugs and remove spark plugs from engine.
CAUTION
Gear housing MUST BE in NEUTRAL position and shift shaft MUST BE removed from gear housing BEFORE propeller shaft can be removed from gear housing.
2. Shift engine into neutral position.
3. Tilt engine to full up position and engage tilt lock lever.
4. Bend tabs of propeller tab washer away from thrust hub (rear), then remove propeller locknut, tab washer, thrust hub (rear), propeller and thrust hub (forward) from propeller shaft.
5. Mark gear housing and trim tab so that trim tab can be reinstalled in the same position. Remove plastic cap at rear edge of drive shaft housing, then unthread bolt that secures trim tab and remove
trim tab from gear housing.
6. Once trim tab is removed, remove bolt from inside of trim tab cavity.
7. Remove 2 locknuts from bottom middle of anti-cavitation plate.
8. Remove locknut from the front gear housing mounting stud.
9. Loosen the side mounting locknuts. (DO NOT attempt to remove one nut before opposite side is loosened sufficiently, or driveshaft housing could be damaged.)
10. Pull gear housing away from driveshaft housing as far as the loosened nuts (in Step 9) will allow, then remove loosened nuts. (DO NOT allow gear housing to fall, as it now is free.)
11. Pull gear housing from driveshaft housing.

All the best, PM me if you want more info.

[familyman]

Sam be careful with the shift rod as it only takes a small knock to put it into gear.What year is it?I have a manual for mine up to 150hp il6.Pm me if this will help.I can scan it and send it to you.
Without the manual you are doing ok so far.When the time comes for re assembly dont force anything as it will cost you big time :(
Put some grease or vaso on the exhaust seal and the water pump discharge tube as well as the two shafts.When you have it together you should be able to turn the prop anti clockwise in forward ,clockwise in reverse and either way in neutral.good luck.
cheers jon

[Dignity]

Thanks Mark221263, the way you printed it s basically what I did even down to the the rubber hammer bit. Didn't seem to want to budge. Should the gear case just slide out or will there be some heavy resistance. As I said it was off in February this year. Will give it another go today.


familyman it is 1991 model

Sam

[Dignity]

mark, reread your thread qand got to point 6 - had a look under the trim tab abd there she was the culprit holding everying in place - removed that bolt and no force necessary, popped straight out

thanks again for your help

[mark221263]

Goodo, I find there is rarely a reason to force things.

Glad to hear all is going ok.

Cheers Mark