1991 Mariner 25hp motor serial # A148102

[grady94]

Have taken lower unit apart because unit will not pump water while running. No obstructions seen. Replaced water cover gasket. Unit does not have a thermostat, this model did not have one. Using rabbit ears to test, have installed new impeller but no other parts used. May go get a complete rebuild kit for water pump. All hoses clean. Can blow air through it seems. What should I try next?

 

[DHPMARINE]

Re: 1991 Mariner 25hp motor serial # A148102

If it overheated to any great extent,the grommet at the top of the water tube (under the powerhead) may have distorted and closed down.Air would still pass.

DHP

 

[grady94]

Re: 1991 Mariner 25hp motor serial # A148102

If this grommet did distort, is this an easy replacement?

 

[emckelvy]

Re: 1991 Mariner 25hp motor serial # A148102

You'd have to pull the powerhead to replace the grommet. Not "easy" but the powerhead is fairly accessible on these once you pull some of the plastic off from around it. You'll want new gasket(s) for the powerhead and also a new driveshaft O-ring, in addition to the grommet.

You can look up parts online for your motor at www.mercurypartsexpress.com

HTH........ed

 

[grady94]

Re: 1991 Mariner 25hp motor serial # A148102

Should I check the opening with a rod to make sure before I pull the powerhead? It looks like six bolts and she is off there. Do I pull the lower unit first or does it matter. Could I attach a hose to that tube with the lower unit off and just blow water through and would that tell me anything?