Thread: Help please

I replaced the water pump impeller on my 115 Yamaha four stroke last year....the impellor and the gasket cost around 40 bucks. I did the work myself , I have no idea what a boat shop would charge.....I called and asked but I cannot remember what it was.

Should be able to get the whole kit for under a $100. Changing the waterpump is a simple procedure. Look it up on youtube, there are quite a few instructional videos for doing it on different motors. Don't skip the marine grease. If it's a new-to-you motor I'd do the whole thing, including the housing.
A weak flow, even a dribble points to the impeller, no flow at all sounds more like an obstruction(but DO replace the waterpump regardless). Find a schematic and trace the flow path, check everything for obstructions. If it's been sitting for a while critters might have set up housekeeping.

I am no mechanic by no means. G-3 is the water pump impeller something i can check if so how do i do that

The water pump is pretty easy to fix. They should be changed every couple of years. It's cheap insurance compared to a burnt cylinder. Trust me. I found out the hard way.

Just undo the bolts that hold the foot on the bottom of the lower unit. Different motors require different proceedures, but basically, lower the foot off the motor and the water pump housing will be right there in the drive shaft

The only way I know to check is by doing what you did....you should still have some water coming out the hole ....if your indicator hole is not wet or dribbling a little water....it kinda sounds like a obstruction. Are you sure you had the water muffs in the right position ?

Originally Posted by g3 fisherman

the only way i know to check is by doing what you did....you should still have some water coming out the hole ....if your indicator hole is not wet or dribbling a little water....it kinda sounds like a obstruction. Are you sure you had the water muffs in the right position ?

not 100% but in the morning going to hook to it and drag it to bulta and leave on tr and back in and lower motor and crank it and see. Only live about 8 miles from dam. Do not want to hurt motor so how long should i let it run?

If you let it run for 30 minutes and didn't set off the alarm then

1) I'd check the thermostats. Mightn't be something holding it open. Prolly good idea to replace regardless If u don't know how old they are

2) u r getting enough flow from current impeller to cool the motor, else u would have set off alarm in 30 minutes. Look again for obstruction on pee line.

3) regardless of obstruction or not. Replace impeller and housing if u do not know it's history. Cheap ins and peace of mind.

Go to bassboatcentral.com boats and motor page. There is a sticky at top with pics on replacing on a merc. Or at least used to be.

Wannabe...