Mariner 3.3 Impeller Renewal ?

[LinTeal]

Hello,
I have a 15 year old Mariner 3.3 ,that has had v limited use.It runs well and the impeller seems to be working fine.
Therfore the only reason to renew the impeller is one of age and ideally one should do so.However is renewal necessary ie do impellers deteriorate with age.I know they don't cost much but they are a bit of a faff to change and I have already changed the gearbox lube oil some months ago.
I would appreciate your thoughts.

 

[VicS]

If it is 15 years old I would be inclined to change it, but dont fit some bit of cheap ebay junk.
It might be a bit of a fiddle but it will be more of an inconvenience if it fails while you are on your annual cruise for example

You dont need to get inside the gearcase AFAICS to change the impeller on this one, so you wont have to drain the new oil again but it might not be a bad idea to change the drive shaft seal while you are most of the way to accessing it.

 

[CLB]

The worse thing you are likely to face is stainless steel bolts that go into the aluminium casing that may not have been removed for 15 years. There is a very high chance that one or more could shear. Go very, very gently.

 

[VicS]

The worse thing you are likely to face is stainless steel bolts that go into the aluminium casing that may not have been removed for 15 years. There is a very high chance that one or more could shear. Go very, very gently.

Drive shaft rusted into the crank shaft is my worst nightmare.

 

[jwilson]

I have done this once: I hope never again. The S/S bolts into alloy castings that have regularly been in salt water and corroded responded to Plusgas and a day later some local heat. That was the easy bit. Getting the two-part gear rod reconnected with a tiny clamp via the small rubber bung hole in the leg was the really difficult bit. Bent wires, needle nose pliers and a lot of cursing eventually got it done.

 

[Mistroma]

I have done this once: I hope never again. The S/S bolts into alloy castings that have regularly been in salt water and corroded responded to Plusgas and a day later some local heat. That was the easy bit. Getting the two-part gear rod reconnected with a tiny clamp via the small rubber bung hole in the leg was the really difficult bit. Bent wires, needle nose pliers and a lot of cursing eventually got it done.

Yes, it is a bit fiddly connecting the gear rod. Pretty simple otherwise apart from any problems with seized bolts.

I did have problems with the actual gear leaver breaking and that was because I had followed the manual's instruction to grease the O-rings with their 2-4-C grease. I used Quicksilver / Mercury 2-4-C Marine Lubricant / Grease with Teflon.

Unfortunately, it caused the plastic to swell and I broke the lever when it became very stiff. The replacement did the same and I removed it before it became too stiff. I ground it down a little and used silicone grease instead. The lever is still fine about 8 years later and I only ever use silicone grease if it needs to be removed.

I would avoid 2-4-C grease if you decide to lubricate the gear lever when putting everything back together.

 

[LONG_KEELER]

Drive shaft rusted into the crank shaft is my worst nightmare.

I was recently faced with the above dilemma . It is so tempting to start wielding hammers.

I completely inverted the outboard ( 2T ) , and poured diesel down the leg and left it for two days.

The leg come off with some gentle persuasion with a rubber mallet. I then fashioned a brush on the end of some dowelling and cleaned the grooves as best I could. It was still not easy to mate the splines on reassembly .

 

[LONG_KEELER]

Getting the two-part gear rod reconnected with a tiny clamp via the small rubber bung hole in the leg was the really difficult bit. Bent wires, needle nose pliers and a lot of cursing eventually got it done.

On my Mariner, you have to reconnect the gear rods, drive shaft, and worst of all, the copper water pipe on to the pump. Even with two people, it was a very difficult job. I will be drilling a second access hole/plug in the leg next time.

 

[jwilson]

On my Mariner, you have to reconnect the gear rods, drive shaft, and worst of all, the copper water pipe on to the pump. Even with two people, it was a very difficult job. I will be drilling a second access hole/plug in the leg next time.

I'd forgotten the water pipe which made it even harder to get them all lined up. I just remember it was a ridiculously difficult reassembly.....

 

[VicS]

I'd forgotten the water pipe which made it even harder to get them all lined up. I just remember it was a ridiculously difficult reassembly.....

I don't know about the Mariner but with my Evinrude you just have engage them in the right order. Just get one started then the next. The difficult one , until you learn to trick of linning up the splines, is the drive shaft

 

[LONG_KEELER]

The difficult one , until you learn to trick of linning up the splines, is the drive shaft

It seemed to help giving the starter rope a little tug to help the splines mate. Unfortunately, it means releasing one hand and arm for the job and putting the torch between your teeth.

A chap on youtube was using a ratchet tie down to hold the leg whilst working which looks like a good idea.

 

[VicS]

It seemed to help giving the starter rope a little tug to help the splines mate. Unfortunately, it means releasing one hand and arm for the job and putting the torch between your teeth.

A chap on youtube was using a ratchet tie down to hold the leg whilst working which looks like a good idea.

Mine does not have a top mounted starter, which would prevent this, therefore I can turn the flywheel , provided the plugs are out. . Or I can turn turn the prop provided it's in gear.

To work on it I clamp it to a stout piece of wood held in the vice, which itself can be swivelled though 90°. and tilt the motor so that it is horizontal.
I also have electric lighting in the workshop so don't have to work with the aid of a torch.