Mariner 25hp 2T Motor Help With Gearbox Separation

John100156

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I wanted to change the impeller on my 2001 Mariner 25hp 2T outboard but I am having trouble splitting the box from the top end.
I made sure it was in neutral then removed the lower casings four bolts, a light tap and she came down but will not budge any further. I dont want to force it as I recall on some larger motors you had to disconnect the forward/reverse gear selector or something but where is it located?

Any assistance appreciated, here are some images:

Mariner Gearbox – partially dropped:

IMG_5447_zpstbwmwpf5.jpg


Marina top cowl:
IMG_5452_zpsr4y3wsxc.jpg


Mariner Front:
IMG_5451_zpsa4b0gzdp.jpg


Mariner STB Motor side:
IMG_5449_zpsbs6epr3w.jpg


Mariner Port Motor Side
IMG_5448_zps3fasgnxm.jpg



Many thanks.
 
Looks like you have all the bolts loose
So you may have the type (there are 2) which you need to release the gearshaft/ selector rod
'wiggle' the gearchange lever and you will observe where it and its bits are connected to the vertical shaft
Usually a c clip or circlip holding the linkage in place. Remove this and it will release the shaft
Don't try and release the shaft at the lower end
You can see the shaft in your first picture (top end) follow where it emerges and release then the whole lot should come away, shaft un all!
 
I just cant find where it links the shaft at the top, will take another look in a day or two - thanks for your reply.

If anyone else has any further information please let me know, I only have the owners manual which doesn't even show how to change the impeller, which is most annoying.
 
John you need to disconnect the shift . Iirc on that engine there is a threaded joint just below the bottom steering swivel bearing. I mean in the little slot right at very top of you first photo - access is better from front than side. Not in the engine housing. Two 10mm open ended spanners needed to open the joint in the shaft
 
Last edited:
Well I managed to get it sorted in the end....

It did not have a 2 section shaft with 10mm nuts, there was two variations, a 1 part or 2 part shaft. My one had the single gear change shaft.

I followed it up through the engine casing and found a spring clip close to where I thought the end of shaft should be, as follows:

IMG_5453_zpsav92id7z.jpg


I opened up the clip which obviously connected to the gear shift linkage and removed it, this cleared the top of the shaft, you can just see the top with hole in it in the following image:

IMG_5454_zps7qvnhopn.jpg


I then removed the four main bolts and the lower unit slid off easily.

Changed the impeller, old one was in good order of course – preventative maintenance, don’t you just hate it.

All done now so thanks to all for taking the time to comment :encouragement::

IMG_5455_zps6zpfwj9j.jpg
 
Well, I ran-tested the motor taking several trips shunting crews from three boats backwards and forwards to Xiringuito's, a restaurant on stilts sitting in the lagoon in Sant Carles, on Wednesday. She worked perfectly, started after 2 pulls. Such a good little motor this 25hp 2T Mariner. She's 14 years old, never misses a beat, always gets flushed out after every use, runs on 50:1 fuel mix, gets new gearbox oil every two years, I even painted the top cowl this time! Must get some photos uploaded when next out, top cowl came up really well...

Now just got to sort-out the HFL Genny (different thread) :encouragement:
 
Excellent read that saved me no end i had been hunting for info on doing the exact same job so thanks for that, i have one question when i removed the unit 4 small washers came out of the hole that look like they fit over the gear rod, i can only presume that they must have been on top of the two pressed sections on the rod at the top, you can just make them out on the last photo, did you have anything on yours when you removed it and any idea what they are for.
Many Thanks
Steve
 
According to the manual there should only be one washer that as you say sits on the end of the change rod stopped from sliding down by the pressing in the rod, I did not find one when I stripped mine down, so had to order one which you just slide over the end then offer the gearbox up, all goes back together just fine. Great motor, never misses a beat.
 
Hi that clears a few things up i will just put the one washer back on, why there was four on i dont know, another thing the water pipe came down also but im hoping it feeds back in ok, if not im not sure how this fits in at the top so will investigate more today.
Thanks
 
Not sure about that - I was a little concerned that the flexible water pipe connector would align, so not sure what to do if the pipe comes down, I did manage to get hold of a workshop manual - so PM me with your email if you want a copy.
 
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