Might have a problem!

[silver6]

Been a while since my last post, but with life and all been really busy. Think I have a problem. Was loading my boat last night and as I approached the trailer it died three times on me. finally got it loaded and got home, got it hooked up to my ears to flush it as I always do and it started and ran just fine but no water was coming from the "pee" hole. Does this mean the impellar is trash and can't get the water to the water pump or is it worse? It's a merc 90 4 stroke that's only three years old. Any help would be greatly appreciative. If it's the impellar I think I can take care of it. It's still under warranty, but I am affraid this is something else.

[wed]

Was water comming out of the propeller / exhaust area when you had the ears on? That is where the majority of the water exits from. The pee hole is just a visible indicator of circulation and it can become blocked. Try running something into the hole to see if it is obstructed. Do you have a water pressure gauge? If you do make sure it is working properly so you know there is water pressure when you are on the water.

Someone will be able to tell you what the typical life of the impeller is for that engine....it seems like I have seen 3 years but not sure. Did you have any audible alarms when the motor died. I think your model should have the same type of alarm systsem as mine. It will beep when there is a problem like overheating or low oil pressure. Good luck.

[silver6]

It didn't beep or anything, but when I got home the pressure gauge was at about 15psi at idle and this is not normal. I have always had about 5 psi at idle and always had a steady stream of water coming out of the hole. Thanks for the reply!

[lakerunner]

I would go ahead and change the impeller. It is easy to do yourself. If you have another set of hands it will help but not necessary. I do my own to save the 100 bucks when impeller is $15.00. On my old 04 merc 4 stk You removed the trim tab, Bolt is under it, I think one on top where you remove a plastic plug, the 2 on each side should be it unless there was a design change.

[HandymanHerb]

If your at 15 psi at idle you have a blockage some where, but they say replace the impeller every 2 years

[silver6]

How do I find the blockage? To replace the impeller I need to drop the lower unit correct?

[slingshot]

OK, first off if your motor is a 2006 it's probably a Yamaha.

Second. You have 15 PSI at idle which proves that your impeller is fine and is good working order.

Third, if you are confident that you have no obstruction in the pee hole and no or little water is coming out the exhaust hub at the prop when the motor is at proper operating temp then you have an obstruction.

Fourth, 15 psi is way high for that motor at idle which means your obstruction is downstream of the water pressure sending unit, probably around the thermostat or in the block which means plumbing between the impeller and the water pressure sending unit is clear.

Possible cause, if your boat was in storage and this is the first time out you probably have some critters that nested in you cooling system (mud dobblers and spiders). No problems when you first started might mean that you impeller pushed that crap into the areas mentioned and caused the clog. No alarms might mean that the obstruction is partial or just enough to keep the motor from hitting the temp that would trip an alarm. Remove thermostat and flush. You also have anode ports that can be removed and used to flush. If you go there it's a good idea to replace the anode.

Manual says impeller should be changed every 2 years, I've had them in a motor for 6 years with no problem in the past. I've even heard of them going 10 years.


Good luck

[silver6]

Thanks for the help. Looks like i have some work to do!