impeller question

[jocko126]

hi all
this is my first post,but i am often in here reading. i just got a boat to fixup . its in great shape. i cleaned it up and everything is looking good.the motoris a mercury 500 50hp 2 stroke 4 cyl. i hooked motor up to water muffs and no water was coming from pee hole. so i checked the impeller and it was bad. so i got a new impeller and i was gonna install it myself,but i dont know it there is only one way to put impeller in. i just dont want to install it backwords. any help well be great. thanks in advance.

jocko126

 

[robert graham]

Re: impeller question

You want the impeller blades turned the same way as the one you took out. Do you still have the old one to look at? Good Luck!

 

[Ken G]

Re: impeller question

Top and bottom is the same. Turn the drive shaft clockwise as you reinstall the impeller housing and the vanes will point the correct way. They would probably correct themselves when the drive shaft turns even if you get them pointed the wrong way.

 

[emckelvy]

Re: impeller question

That's correct. It's an Old Wives Tale that if you turn the blades the wrong way when you install a new pump, that it won't pump.

New, flexible blades will 'right' themselves as soon as you start the motor. In fact, when the motor is running at speed with the boat in motion, the blades of the impeller don't even touch the sides of the water pump; they 'curl up' and what you've got is a 'circulating pump'. They only touch the sides of the pump for "positive" pumping action at lower speeds and when the boat is stationary.

Now, if you were to turn around an old impeller whose blades had taken a 'set', that's a completely different matter. Probably won't pump at all, and a high probability that the blades will break!

All that being said, it's just Good Shop Practice to turn the impeller the way it's naturally gonna be spinning, when you install it. But if you get it backwards, won't make any diff in the long run.

BTW, most American and Japanese outboards (with very few exceptions) rotate their crankshafts clockwise as viewed from the top of the motor.

Of course there were the old Merc Dockbusters (Direct Reversing) motors that ran backwards for Reverse but that's a different breed of cat altogether!

HTH..........ed

 

[jocko126]

Re: impeller question

thanks guys for your great answers.

cya later

jocko126