Mercury mariner 15 hp 2 stroke impellor change

[Max...]

Anyone done one and can share tips, how to, exact parts need?

[The Gurnard]

I did my 25hp at the end of last season and didn't have any trouble..its straight forward. I had the service manual ..I already linked you the 15hp one ..and there are some good U tube videos..just google U tube and search for impeller change

here is one that explains removing the leg.. think its same as yours..it was same for my mariner 25hp anyhoo...

Mercury 15 hp Shift Shaft Retainer Location and Lower Unit Removal - YouTube

Look on Black Dog marine site for the impeller.. I got mine there and it was send next day delivery..costs around 17 quid

hope that helps some

[Max...]

Thanks very much, will check it out - do you need any other gaskets or seals etc?

[The Gurnard]

nope.. not for my waterpump...everything was in good nick.

You will find a full waterpump kit of blackdog marine if you want to go that far though..or just the impeller. Try checking the impeller and pump gaskets first ..the full kit with gaskets was around 60 quid I think ?

Its worth remembering to get the gear box oil plug gaskets there too ..if you want to change the gear oil. they don't cost much

Only other thing I changed for peace of mind was the thermostat..mine was a bit corroded.

Any problems finding the parts on the site ..just ask..or speak to Rob..he was a true gent and very helpful when I was looking for bits

[Max...]

Thanks again, leg off this morning - first time for me and pretty easy once you know how.

The impeller actually looks in perfect condition - clueless as to how long it's been in there but obviously I will change it anyway with a new gasket. Rang Black dog (Dan) very helpful as everyone says.

'Stat is out, really clean and tested - working fine.

Couple of points I've learned from doing it - the detent spring on the yoke does not need removing as per manual, the coupler pops off fine (this helps as the two bolts securing the spring are a PITA to access).

And a strip of gaffer tape left wrapped around the shift shaft allows you to measure down to the reverse lock actuator so it can be replaced in exactly the same position.

[uncle al]

Just a team tip, when you have to remove the G/h for any reason, if the impellor hasnt been changed for over a twelve mounth replace it ,it could save you a lot of trouble later on.If when you take it out and it looks good. Dont reverse it and put it back onto to drive shaft, the vanes will eventually break off then you will be in trouble.When refitting the g/h put a small bit of grease on the fixings and on the splines of the drive shaft, NOT the top of the driveshaft, just the splines. You will then find you have an easy job next year, that is use marine grease.

[Max...]

Got that. Workshop manual specifically states loctite on impeller housing bolts and gear housing to leg bolts. Black dog marine told me to grease them instead, any thoughts?

[uncle al]

forget the loctite use grease, but use it sparenly, read my bit about the team tip.

[Max...]

Thanks Al, understood.

One last query, re' the bead of RTV sealent to prevent exhaust gases going into the pump - is it just the small 1" or so strip that needs the sealent (see old sealent on pic below) and not sure what 'RTV' is - can I use Sikaflex?

[uncle al]

All I used was the sealant that I bought from B&Q or homebase somewhere like that, the stuff you sealed sinks baths etc it will be ok.