Tips for impeller change on 2011 Mercury 150 optimax

[mickab9]

I’m about to replace the impeller. Any top tips/pitfalls removing the lower unit and changing the impeller? Many thanks.

[carldalmas]

Originally Posted by mickab9

I’m about to replace the impeller. Any top tips/pitfalls removing the lower unit and changing the impeller? Many thanks.

Hi mate to change impeller buy a full kit with new housing and gaskets
The first job is to put the gear lever in forward Before removing gearbox
Carefully undo the bolts on gearbox dont forget hidden ones on trim tab be very careful taking bolts out as they can seize up in alloy and break off easy wd 40 will help when all bolts are out get a bit off wood a tap gearbox down make sure it does not crash to the floor ! They can be difficult to seperate depends on past maintence !
When down get the shaft out remove housing slide up shaft you will see impeller easy job ! Make sure plates are the correct way around when you rebuild it marine grease use yamaha triple grease on bolts and flange joint on rebuild
When you put it back on move the prop a bit to aline the splines up

[mickab9]

You are a star sir. Thank you. I managed to get an impeller but need the housing as its burnt out. Great advice.

[Waterman]

I did my 200 recently. Very straight forward, as stated above you may have to turn the shaft to align the splines when refitting lower unit.
Few pics of the job

[mickab9]

Thanks very much. Ps. Which way does the shaft rotate? My impeller is in pieces and I could do with getting the blades the right way round! As per your picture?

[carldalmas]

Originally Posted by mickab9

Thanks very much. Ps. Which way does the shaft rotate? My impeller is in pieces and I could do with getting the blades the right way round! As per your picture?

Hi dont matter but if you know which way your prop turns forward by looking at blades is the big clue ?
Make sure you put some greece or even cooking oil on impeller before install fits easy and gives it a bit off lube help it on start up
As for direction off blades they will flick the correct way anyway
Make sure your base plates match up with flow holes
Do not fit them upside down or it wont work ? And you fit a rubber seal overshaft down to top off housing
Use yamaha triple greece on flange joints and bolt threads so next time its free and change anodes
Carl from uk

[carldalmas]

Originally Posted by carldalmas

Hi dont matter but if you know which way your prop turns forward by looking at blades is the big clue ?
Make sure you put some greece or even cooking oil on impeller before install fits easy and gives it a bit off lube help it on start up
As for direction off blades they will flick the correct way anyway
Make sure your base plates match up with flow holes
Do not fit them upside down or it wont work ? And you fit a rubber seal overshaft down to top off housing
Use yamaha triple greece on flange joints and bolt threads so next time its free and change anodes
Carl from uk

Check in holes or hover any old blades broke off as may cause a blockage
Also drop gearoil and change that while your at it !

[carldalmas]

Originally Posted by carldalmas

Check in holes or hover any old blades broke off as may cause a blockage
Also drop gearoil and change that while your at it !

Triple greece is blue stuff for salt water protection brilliant stuff !

[Waterman]

Originally Posted by mickab9

Thanks very much. Ps. Which way does the shaft rotate? My impeller is in pieces and I could do with getting the blades the right way round! As per your picture?

As the others have said, once the impeller catches the shaft the blades will move into the right direction, the pic is of the old impeller before i removed it, hence the blades being bent, I smeared a tiny bit of fairly liquid on the new one and inserted into housing.
I also Found a second pair of hands for aligning the gear selector rod/lever came in handy for the reassembly [emoji1303]

[mickab9]

Thanks Carl. That’s a great help. Why didn’t I think of prop rotation ��.