# Yamaha 9.9hp 4-stroke



## WagTheDog (Apr 15, 2008)

Hi all,

I recently took ownership of a beaten up 1978 Lancer 28. The engine however appears to be in good condition. It's a 2002 Yamaha 9.9hp regular shaft, set up for remote control from the cockpit. One of the other boat owners came over yesterday and told me that I should replace the water pump immediately. The boat has been on the hard for some time and my sense is that the motor has not been used much. Now, trying to get the boat into the water in as cost effective a way as possible (and haveing already racked up a substantial bill on paint, coating and a bunch of other stuff), that's the last thing I need to hear. 

Any thoughts on his comment/these engines in general? Oh, and by the way, if anyone has a owner's manual they would be willing to share by way of fax, that would be great.

Thanks!


----------



## sailingdog (Mar 19, 2006)

Wag-

It would probably be wise to replace the impeller in the water pump on the engine. If the engine has been sitting for a long time, the chances are very good that the impeller blades have taken a set, which will make them less effective and more likely to break off.


----------



## jimmyb116 (Feb 20, 2007)

Nah Yamaha impellers are bomb proof. I’m on my 5th Yamaha outboard never had any problem with cooling. The 8hp high trust on my sj24 has the original one, 3 years old and looks like brand new. I just checked it last week during spring service. Try it and if you have a good stream from the pee hole you are good to go.


----------



## chucklesR (Sep 17, 2007)

I'd at least pop the cover and take a look, and if the cover is off you might as well replace it. It's not much work and despite some folks luck - do you really want to be 5 miles out, find you have a problem with the sails, weather closing in and a overheated motor? Prudence says check it out and test it by running the motor in a bucket or with a hose adapter before you launch.
As for owners manuals, try here:
Outboard Owners Manuals


----------



## WagTheDog (Apr 15, 2008)

Chuck,

I'm inclined to agree with you. We have two small kids to boot and I'd hate to put them through a harrowing experience. I guess there's nothing wrong by erring on the side of caution. Thanks for the link to the owners manuals - I found it prior to my initial post but unfortunately the Yamaha web site does not allow for downloads or screen prints.

J


----------



## gershel (Feb 4, 2001)

chucklesR said:


> I'd at least pop the cover and take a look, and if the cover is off you might as well replace it. It's not much work and despite some folks luck - do you really want to be 5 miles out, find you have a problem with the sails, weather closing in and a overheated motor? Prudence says check it out and test it by running the motor in a bucket or with a hose adapter before you launch.
> As for owners manuals, try here:
> Outboard Owners Manuals


 Pop the cover? What cover? To change the impeller, the whole lower unit must be removed. Definitly not easy. Put a hose connected to earmuffs on, and run for a while. Check for a good flow from the pee-hole. If there is no flow, remove the thermostat, and try running without it. If that allows a good flow, then relace the thermostat. Easy to do. If no flow, then you will have to replace the impeller.
I learned this the hard way. Usually the impeller is OK.

Marc


----------



## WagTheDog (Apr 15, 2008)

Marc,

Thanks, that is the cost effective answer I was looking for. Now...let's hope that there's good flow when I run it as suggested. Just so as I know, where is the thermostat located?

Thanks,

John


----------



## gershel (Feb 4, 2001)

WagTheDog said:


> Marc,
> 
> Thanks, that is the cost effective answer I was looking for. Now...let's hope that there's good flow when I run it as suggested. Just so as I know, where is the thermostat located?
> 
> ...


Hi John, looking down on the top of the engine, remove the plastic flywheel cover. (thumbscrew aft, sliding alum. rod fwd). Thermostat housing is just aft and below the flywheel. 2-10mm bolts. Leave the water hose connected. Easy.
Good Luck, Marc


----------

