Few questions about 1985 Yamaha 25hp

[Joynerswf]

I recently bought a 1985 Yamaha 25hp 2 stroke and have a couple questions. Yesterday, motor was running great. I changed the lower unit fluid and found really old oil but fortunately no water. Afterwards I fired it up and had no water peeing out. Opened it up and found a shredded impeller. Is that just a big coincidence or did something happen while changing fluid? The impeller parts were very soft and almost jelly like which seemed weird. There was also some bubbly milky-white looking fluid under the water pump housing.

Any advice? This is my first outboard so have no idea if any of these things are normal or not

 

[tommarvin]

1. Nothing happed when you changed the LU gear oil.
2. Your a smart guy for catching the no water out the indicator hole.
3. I fthis is your first impeller, U-tube explains it well, you have to orient the fins for a clockwise drive shaft.
4. the bubbly milky white fluid could be the start of a leaking seal on the drive shaft.
5. Were any fins on the old impeller missing, if so try to find them, could plug the cooling system.
6. your carb(s) are probable dirty, clean/rebuild if you suspect a fuel delivery problem.
7.change all fuel filters

 

[99yam40]

there is a good chance someone put something on the rubber impeller or ran the motor in water contaminated with something that attacked the rubber and destroyed it.
It should not be very soft and jelly like.

I would remove and test the thermostat to make sure it is functioning properly also .
gives you a chance to see what the cooling passage behind it looks like too

 

[Joynerswf]

Thank you for the replies, I really appreciate it. I have already ordered the full water pump repair kit and thermostat from ********** so unfortunately not much I can do until they arrive. I'm pretty sure parts of the impeller have lodged themselves in bad places. When I say it was shattered, it's not an exaggeration. I'd be more surprised if pieces WEREN'T lodged somewhere. Shooting a hose up the water intake seems to be a bit clogged. Going to borrow my buddies air compressor and try to shoot it back out from the discharge hole.

Tommarvin, I have done an intense carb cleaning just short of a rebuild, gaskets seemed fine. Do need to replace fuel filter though.

I am a bit worried about what the previous owner said he has done, I just bought it last week. He told me he had changed the water pump recently which I am now doubting. And 2 of the 4 bolts holding on the LU were missing!!! That was terrifying to find. Ordered those as well. The motor has great compression which is only reason I'm bothering to to fix it up. I think it can be a good motor once I take care of this stuff