Prop and water pump question Yamaha 115 2 stroke

maineiac5586

Chief Petty Officer
Joined
Feb 14, 2009
Messages
623
I have a 1985 yamaha 115 and was thinking of getting a spare prop. I am trying to find some identifcation on the prop so I can order the same one. The only thing I see near the hub is 19 k or a (not sure which)., is there more identification somewhere else on the prop?
my other question is that I ordered a water pump kit thinking it was an oem kit but I didn't see that the listing was only giving me the oem part number as a reference. The kit is actually a Sierra kit and includes 2 o rings, impeller, impeller cup, plate, key, and a gasket. Is this sierra kit ok? Anyone have any experience using this brand (good or bad). The impeller in my motor is the original at 28 years old!!! It actually still works fine but I think I pushed the envelope far enough. Let me know if I should go ahead and install the aftermarket kit or is it mandatory to use an oem yamaha kit? thanks
 

Bamaman1

Lieutenant Commander
Joined
May 15, 2011
Messages
1,895
Re: Prop and water pump question Yamaha 115 2 stroke

Your Sierra water pump kit is just fine. It's doubtful that it's the original impeller, as they should be changed every couple of years.

Be sure to drain your lower unit into a clean drain pan so you can see the condition of the grease that drains out. On a lower unit that old, you want to make sure there's no water intrusion. And you should have the lower unit pressure and vacuum tested by a qualified marine mechanic. To replace the seals is about a $300 job.

If you drop the lower unit to change the impeller, remember that there's a bolt under the trim tab that's got to be removed from the bottom. You have to remove the trim tab on the back of the anticavitation plate and the lower unit will drop right down.

I too have a 1985 115 hp Yamaha, and they're a really good motor. Only thing I've done to my motor is clean the carbs twice and changed an oil pump module for $230 15 years ago.
 

maineiac5586

Chief Petty Officer
Joined
Feb 14, 2009
Messages
623
Re: Prop and water pump question Yamaha 115 2 stroke

I know it is hard to believe but we are the original owners of the outboard so I know the impeller is original. Awesome motor. We too changed the module and just cleaned the carbs for the first time. I have it on a 1984 chris craft scorpion 167 bowrider and it pushes it almost 50 mph! Do you have an answer for the prop question? What do you have your motor on
 

maineiac5586

Chief Petty Officer
Joined
Feb 14, 2009
Messages
623
Re: Prop and water pump question Yamaha 115 2 stroke

still looking for an answer on how to id my prop. all i can see is 19 k or a not sure? is there any other place I need to look for identification?
 

maineiac5586

Chief Petty Officer
Joined
Feb 14, 2009
Messages
623
Re: Prop and water pump question Yamaha 115 2 stroke

how can I tell if my current prop is stainless? Is there a way to check with a magnet?
 

MARV1

Seaman Apprentice
Joined
Jun 27, 2013
Messages
49
Re: Prop and water pump question Yamaha 115 2 stroke

Should be a 13x19 or 13.25x19 pitch. Correct #'s in front of hub, have to remove prop to see them... With that kind of speed it won't be hard to push a 20 pitch or 21 pitch prop and you'd be around the 50mph area, pick up speed is never a bad thing... When I had a 2 stroke 15 years ago I liked the Cabela's brand prop in 13.25"x19"p, worked great and couple mph faster than the Yamaha 19K...
 
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