Preventive Maintenance

JoeW

Senior Chief Petty Officer
Joined
Nov 8, 2003
Messages
664
I have a 1988 100hp Merc Ob. This motor has been great, but I'm wondering about what things I need to do to keep it that way. This motor has never had its impeller or t-stat replaced. Is this okay, or should I replace them now? What else should I be looking out for?
 

KCLOST

Commander
Joined
Jun 22, 2002
Messages
2,095
Re: Preventive Maintenance

Yep,<br /><br />If it has never had service to the water pump or stats, do it now.....<br /><br />You don't want to find out the hard way that the impeller/pump has gone bad.... After is has, the whole motor may burn up... And the motor is history....
 

KCLOST

Commander
Joined
Jun 22, 2002
Messages
2,095
Re: Preventive Maintenance

Also, take a look at the poppet valve (if you have one) and also do a Lower Unit oil change...<br /><br />The gear lube should be replaced every season...<br />Just drain it out (follow your manuals directions) and fill it with new...
 

Merc805

Petty Officer 1st Class
Joined
Feb 14, 2004
Messages
202
Re: Preventive Maintenance

As far as impellers go.. there are varying opinions on how long they last, but if you make sure that the impeller is wet before you start the motor, you will mininise the chance of it sticking or burning in the dry housing. I have read one instance on this forum about an impeller that has not been changed since new (80's motor) and it is still going. But having said that.. you NEED to remove the L/U periodically to ensure that it doesn't sieze in the crank shaft spline. Also, the impeller can start to break up and the pieces will clog you cooling system.<br />Keep your fuel clean, as a clogged carb can create a "Lean condition" and destroy pistons.<br />Periodically check the Geracase for water and replace the oil as KCLOST said.
 
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