ysb8 impellor change - advice please

[Burnham_Bob]

i've changed the impellor on my 1GM10 every season - fiddly but easy. I've never done it on the YSB8 and I've just got a new one from French Marine and I'm confused. The 1GM10 is just a push fit and a flat on the inside brass collar fits a flat on the drive spindle.

the impellor i've just got has a hole both sides and a threaded stud that obviously goes through it. how does it fit? there is a slot in the head of the stud as if a screwdriver can be used but you'd never get one in the moulding the impellor rotates in.........

only thing i can think of is that the impellor pulls out and there is a small shaft that comes with it, you replace the impellor on the shaft and reinsert.........

i haven't even had a close look at the engine yet but rather than start something i can't finish i'll leave it until i get some advice.....

can anyone help?

 

[Richard10002]

On mine, (a Johnson pump, Jabsco or VP branded), the impellor has ridges on the inside which are matched by ridges on the stud it slides onto. Once you've got the blades squashed to fit, (in the right direction), it just slides in, (easier said than done). AFAIK, it can go on either way round.

Not sure if that helps

 

[Burnham_Bob]

no this one is smooth - could understand if it had ridges but it's this threaded stud that's got me fooled......the inside brass collar is perfectly round - no ridges no flats....obviosuly the stud goes through the drive shaft but how does one get at it to put it on?

maybe it'll be clear once i get the flange off and look but i need the engine to get home (its a new boat to me and its not at my home port) so i'd rather not start a jib i can't finish

 

[dickh]

If it's like mine(Jabsco), the stud screws through the impellor before fitment, equal each side(the metal bush isn't threaded)- there should be a hole through the rubber. There is a slotted shaft in the pump body and it just pushes on. To remove the original impellor I use a cheap long nosed pair of pliers(£1 from the market) which I heated up the tips and bent each tip inwards so it's like a crabs claw - just one pull and it's out.

 

[Spyro]

It's very simple once you get the old one out. It fits onto a slot on the drive spindle. a tip is to remove the pump and turn it to face outwards. it's only fixed on with 2 bolts. you may have to take off the hoses to turn it round but it makes removel and refitting of the pump cover so much easier.

 

[Burnham_Bob]

thanks - that makes a lot of sense about the slot in the drive shaft - it was the fact that the threaded stud was supplied loose - had it been in palce it would have been obvious how it fitted!

 

[simon_sluggett]

The water pump on the ys series is facing to the back of the engine , which makes changing the impellor in emergencies very hard. really you have to unbolt the pump to get to the cover plate- been thinking about changing the pump so it faces to the front but not sure how to engineer it.