Good old Johnson, my story...

I rebuilt both carbs on my 48 hp Johnson and installed them today. After a couple of attempts it fired right up and ran great in a barrel of water but then noticed no tell tale stream. The tell tale stream has been getting weaker during the last few outings. After checking thermostat, I pulled the lower unit, shot water up the intake tube and water came gushing out of the thermostat housing (had the unit removed) and water came out of the tell tale. So, opened up the water pump housing and found that the "key" in the impeller was shot and just about worn out! This impeller, key and housing is about 7 months old and has been in only about six outings in salt and fresh water with a flush after each outing!

My long gone 15 hp Evinrude went four seasons before needing a new impeller. It really wasn't an impeller problem but clogged water passages on that old one!

So, how long does your water pump last?

I've heard every 2nd or 3rd season it should be changed, but I had an 82 8 hp Johnson that was good for the 5 years I ran it

in my 80 25hp johnson(ive owned since it was brand new)i still have the original in it.........other motors ive owned they have lasted 10 yrs or more...

The older outboard water pumps have short veins which should be replaced every 2-3 years where the newer outboards have longer veins which can go 5 + years but anymore than that your taking a chance on a $20 part for a $1500 + motor.

The longer you don't take lower apart the harder it is to get lower off. [-X

My dad bought a 79 Johnson 9.9 brand new in 1980. It has been used hard it's entire life. Passed onto me, then to my brother, and now back to me. A wrench has never touched it. Never a water pump, a lu oil change, or even a carb rebuild. It has been sitting in my garage for a couple years. I put it on a stand about a month ago to see it it would start. Three pulls and it was running and pumping water like it was new. I'd say it's been a good one.

chavist93 said:

My dad bought a 79 Johnson 9.9 brand new in 1980. It has been used hard it's entire life. Passed onto me, then to my brother, and now back to me. A wrench has never touched it. Never a water pump, a lu oil change, or even a carb rebuild. It has been sitting in my garage for a couple years. I put it on a stand about a month ago to see it it would start. Three pulls and it was running and pumping water like it was new. I'd say it's been a good one.

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Youve been lucky. Rubber dry rots and deterierates over time. Your impeller is over 30 years old. It may have been a good one up to this point but when it comes apart your gonna have bigger issues. All those rubber pieces wind up in your engine and clog all your water passages. If you dont catch it in time, you over heat the motor and blow it up. There is a reason the water pump impellor is on the "preventative maintenance" schedule!!

Something to think about here. The days of the lightweight and powerful two-stroke technology are, sadly, over. We all have enjoyed these engines. I would strongly urge those who continue to own, run, and enjoy these engines to at least change an impeller every 2-3 years. For the price of frying a powerhead this is cheap insurance and you cannot replace this technology anymore! If you buy an OEM impeller the part is warranted for a year which is nice to think about!
And to the guy with the 1979 9.9.........get with the program and do the maintenance!