mercury water pump impeller

[PRO V LE]

I beg for mercy! fishound you made the statement's "all that money" and "aint rite" youre spelling by the way. The point I was trying to make is that this is a normal maintence item that as a boat owner you should know. You're post about water pump impellors being made from rubber pulled my chain. H. Bob gave a excellent answer to the reason why.
School teacher please read this entire thread and tell me where the negative comments started!
BTW. 40+years mechanic.
Now let's all go FISHIN!

[CTFSHWHISKER]

thanks for the info sglass its a shame give all that money for a motor and the main part of the cooling system is made of rubber! lol aint rite.

the reason they are made of rubber is the way they work..when the driveshaft turns the impeller{offcenter} it squishes the vanes on one side of the housing,on a merc impeller the vanes are not very long,as opposed to an omc, and if they set unturned that one side will hold it's form,making a flat spot.in a sense at this point the impeller basically "spits" water..my dads xr4 150 gets run maybe 5 times a year,i have to put one it every spring or it will over heat.
mercs don't hold alot of pressure at idle.3-6lb so it won't pee real strong unless you rev it up slighty,and the t-stats are open. cool garden hose water they may not open all the way up at idle to allow full water flow.if you aren't getting any pee stream even with water pressure on the muffs something is plugged.probably some mud dabbers like stated.
it would be hard to build a pump of meatal to fit the small area and withstand 5,000+ rpms.that would take some good bearings and materials..and as bob stated the samd and debri would eat that thing up quik..

[fishhound]

alls good no harm done

[Dakota Kid]

My b-in-law had the same trouble years ago out of his 50hp merc. A mechanic rerouted the water line somehow. I need to look at it again. But as far as it not peeing, it might not be the impeller. Insects will crawl in and make a home out of it. But if you are going to take a look at the impeller, just put a new one in. couple of dollars vs. what could happen and most likely will happen.

A reminder to everyone. No matter what size of motor, do not use a garbage can to supply water. What happens is that the exhaust and peeing water creates air bubbles in the can. When the motor picks up the water, it also picks up the air bubbles. It will still pee, but won't have the water needed to keep it cool. Always use ears.