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View Full Version : b94 Johnson 60hp OB water pump problem



Matt Winkler
05-06-2003, 09:26 AM
This is my first boat and have no experience with OB motors (though I am mechanically inclined).I have what i believe is a '94 60 hp Johnson (boat is a '94). I put the boat in the water yesterday and immediately noticed a hesitation/cavitation when giving part or full throttle. There was no water streaming out of the small orific located in the bottom of the cowl. I am going to assume that the water pump/impellar is NG.
If that is the case how do I replace the pump/impellar?? What tools do I need? and tips or hints? please keep in mind I have almost no working knowledge of OB motors so pictures/diagrams and descriptions are a plus.
Thanks in advance for all the help !!!!

Matt (the hopeless)
p.s.- my father in law told me a man two happiest days are the day he buys his boat and the day he sells his boat. Hope this isn't going to prove to be true.

jupiterzeke
05-06-2003, 10:43 AM
" Matt;Sounds like the carbs. are varnished up and/or timing advance is sticky.About the "no water"that engine won't run very long without water--30 seconds before its fried most likely is the 'telltale' is plugged ,blow it out.You need to buy a shop/service manual,Andrew says the REAL ones are available here,do NOT buy a 'brand x' manual as you will be disappointed.Zeke "

Matt Winkler
05-06-2003, 12:44 PM
Thanks for the fast reply..... What is a "telltale"? I have used compressed air and blow air thru the small orifice and can feel air coming out of holes in the lower end. When I use the rabbit ears an run it out of the water it is fine thought there is still no stream of water coming out of the rifice in the cowl.
If I get a manual is this something I can fix easily or should I just take it to a marina for repairs??

jon
05-06-2003, 04:30 PM
" Matt,

I'm assuming this engine idles fine & will spin the prop forward/reverse, but just doesn't like pushing the boat above an idle in the water. Before you go into anything, a good idea is to check the compression on that engine, you want to see all cylinders within about 10 psi, probably around 90-140 (not sure on normal compression on that engine). This will prevent you from wasting time if there are major problems to be delt with.

The telltale is the little rubber fitting on the cowl where the water normally "pees" out of. It connects to a hose that exists the block somewhere, the water comes up from the pump, through the block & out that telltale, this lets you know all is working.

As far as what work to have the marina do & what to do yourself - that's your call, as stated - buy the book and then judge.

To diagnose & fix: Sometimes bugs or misc debri can clog up that telltale - blowing air through it can unclog this, sometimes people use wire, I don't - just be sure not to break it off in there if you do. After an attempt at clearing it out, run the engine again, give it 5-10 seconds, and if it doesn't pump, shut it down immeadiatly.

Take off the lower unit, read the book on this, it's very simple, but you've gotta take all the nuts/bolts off, including one hiding under the trim tab, and also you must disconnect the shift rod under the powerhead first. Slide the lower unit out & now you've got access to the water pump assembly - pull the cover off and take a look, if the impeller slides around the driveshaft and/or is melted (run without water), torn up (sand/wear/run without water), or the output from the pump wasn't correctly lined up with the tube in the exhaust housing during assembly etc.. etc.. you've found your problem.

If all appears well & it's a mystery what went wrong: Take a garden hose and slip it over the tube that the water pump fits to - turn the water on and you should see a stream of water coming out of that telltale. If there is water coming out, your pump has some issue, else the line is clogged - blow compressed air down the telltale; it will probably be easier to flush it out downwards as that's where anything substantial must've come from (ie pieces of a junk impeller, sand, salt, debri - etc.. etc..).

Jon "

Matt Winkler
05-07-2003, 11:31 AM
" last summer we had a similar problem... It turned out to be a diode went bad that puts the motor in "safe" mode when it is reaching overheating temperatures. It idles fine and allows you to engage the motor and travel at offidle only.
It is doing the same thing now.... I believe the water pump/impellar is NG and there is no water making it thru the motor and coming out the telltale. This would lead to high temp./ overheat conditions and the motor/electronics would put it in "safe" mode.
We have ordered a water pump kit and a service manual so that will be our starting point.
Being novice boat owners we have been told that the carb may be varnished because we did not winterize it properly. I truely hope we will skate by on that one, I am not looking forward to rebuilding a carb ( though I have done several auto carbs).
Thanks to all for your input! Keep it coming, there is always something to be learned....

Matt "