1984 9.8 Mercury impellar

[dls-uscga]

Every year for the past 4,i have replaced the impellar on this outboard. The ones i removed looks new with no damages,the problem is that if the impellar is not in use ,say for the winter, the rubber keeps its shape of the pump and not flexable enough. The pump case is really small ! Never had any problems with water pumping while in use for the fishing season,just when i store it through the winter months. And besides i store it in my warm basement.
Never had problems with Evinrude or Johnson motors same size and year,Replace these every 4yrs.
Is there a person that may be the problem solver? Dave

 

[oldman570]

Re: 1984 9.8 Mercury impellar

The small area impellers will take a set when the motor is stored for a period of time. They will usually work for a few years before they need to be replaced. On these type of impeller, you can usually go ahead and run the motor in a barrel or in the water when you first take it out of storage and run it to see if the water pump needs attention. When run in a barrel make sure that the water is above the cavitation plate about 3 inches, so the water pump is below the water and will prime as it would when out on the water. It is sill best to check the impeller at least every other year for any broken impeller fingers or other damage to the seal area of the cup and plate. If all looks good and the motor pumps water fine then I leave everything as is and run it.
In all reality the replacement cost of the impeller and the satisfaction knowing that it will not be a problem latter is good cheap insurance. JMO
Oldman570

 

[racerone]

Re: 1984 9.8 Mercury impellar

These motors do not have an overheat warning system !!----------The tell tale is a visual indicator that the waterpump is doing something , but only when you look at it.-----------A new impeller every 4 years is the thing to do.-----Seen many of those motors ruined by folks who just do not know how important this is.

 

[out 2 launch]

Re: 1984 9.8 Mercury impellar

You state that you believe the impeller is taking a set due to non-use which is a common problem with impellers. Simply go down into the basement, grab the pull cord and slowly pull the motor over on a regular basis. This will exercise the impeller and may help delay the set.

 

[Scott Danforth]

Re: 1984 9.8 Mercury impellar

are you buying the sierra impeller or are you buying factory mercury impellers? There is a difference

for my Wooster Hellion project, I have 2 1984 9.8's and am replacing the complete water pumps because the P/O's did not regularly change the impellers, and on one motor, the unit was run dry and melted the plastic pump

 

[dls-uscga]

Re: 1984 9.8 Mercury impellar

You state that you believe the impeller is taking a set due to non-use which is a common problem with impellers. Simply go down into the basement, grab the pull cord and slowly pull the motor over on a regular basis. This will exercise the impeller and may help delay the set.

are you buying the sierra impeller or are you buying factory mercury impellers? There is a difference

for my Wooster Hellion project, I have 2 1984 9.8's and am replacing the complete water pumps because the P/O's did not regularly change the impellers, and on one motor, the unit was run dry and melted the plastic pump

I have tried all above,Mercury impellers,turning motor over once a week all winter long. Next going to put it in a bucket of water downstais and turn it!lol Dont do this unless in so water.
Last time i turned it just a little bent and deformed the fins worse than before! Maybe use KY Jelly in a bucket to keep the rubber soft!lol
Never no problem with Johnson or Evinrude they last 3-4 times better. Are the bigger with better rubber? Same size motor too?

 

[racerone]

Re: 1984 9.8 Mercury impellar

Fact ----The impeller on the 9.8 is a short lived design.--Perhaps one of the motors that needs impeller replacement most often.--------Impellers are all black , but they are not " all the same "