Mercury water pressure low

[Matt]

I noticed yesterday that the water pressure coming out of the motor seemed lower than usual and wasnt very strong at all. Especially during idle. Almost like it was struggling. Its an 01 2-stroke 40 HP Merc. Any thoughts on what I should be looking for/at? Hoping to start with the easiest fix first. Any help is appreciated!

Matt

[Trackertroller]

Not a difficult fix and fairly inexpensive

First make sure the mud wasps have not packed the line with mud

If that is not it,

Then most likely the impeller or thermostat.

Less than $100 at a shop

[Matt]

Ill check the lines and go from there. Assuming thermostat first and if its still weak the impeller? Would a shop have them in stock, or would I need to order them online?

While I'm thinking of it, I've had my trim make some very odd noises while idling. Like I was hitting up and down over and over but I wasn't touching the trim and I don't think it was even moving, just making noise.

[Reelax]

I would guess impeller, it may be original. Good luck!

[spinner]

Easy job to do yourself Matt. Just 3 nuts to separate the lower unit pull it off and the 2 or 3 little nuts that hold the impeller in place and pull out the old and the put the new one back in. Its easier if you keep it in neutral.

[fishmaster176]

Most any Merc. Dealer will have the impeller kit. If the pressure has been fine, but suddenly isn't, the impeller is more likely the culprit. Finding a shop that can do it quickly this time of year may be an issue. Not a difficult job, but can be disastrous if done wrong. Worth the price to have it done by a marine mechanic. YouTube has great videos on the subject. Good luck.

[Matt]

I'm not sure if its always been like this, but I cleaned the outlet out and it seems a tiny better. This is the flow during idle in this pic.

Anyone know if I should be concerned with this pressure?



I found a few how to videos on almost the same motor and it doesn't seem too diffcult. There are some key things to make sure of though.

[Vtmopar]

Impelller should be changed after 2 seasons on the water.
Depending on hours.
Cheap maintainence. Important is too make sure its not on upside down. It can be easily done not paying attention.
Theres alot of youtube videos out there to help.

[Matt]

Impelller should be changed after 2 seasons on the water.
Depending on hours.
Cheap maintainence. Important is too make sure its not on upside down. It can be easily done not paying attention.
Theres alot of youtube videos out there to help.

The previous owner told me he had never changed it. So i am assuming it is original. I'll have to grab a new one.

[Matt]

Should I buy the kit that replaces the housing and seals as well, or just the impeller?

[Vtmopar]

Be a good time to do it if its never been done.
Good luck, not a terrible job if you take your time.

[Reelax]

Should I buy the kit that replaces the housing and seals as well, or just the impeller?

Go with the kit, of any of your old seal or housing has an issue it will ruin the impeller very quickly... Its best to replace all you can with the kit IMHO...

That stream look a little weak even at idle....

Good luck Matt

[Matt]

I cant find the exact kit I need - my # is 1041412YN. I found some random kits for like $30 but dont know if they match for sure. Guess I have to call a merc dealer?

[Vtmopar]

Call around might luck out and find a dealer that has one in stock.

[Matt]

Found what I need but ill call around tomorrow before ordering.