Gearcase lubricant capacity ? Manual wrong ??

[oldtortuga]

Mercury 60HP 4 Stroke EFI Year 2004-2005 with (I think) 4 1/4 inch diameter gearcase. I know it is not the Bigfoot.
Book says capacity is 24 oz.
Every time I change this lube it holds only 10 - 12 oz.
I carefuly follow the directions about leveling motor, allowing to drain completely, refilling til overflow at front vent plug and then reinstalling front plug then filling til overflow at rear vent plug and then reinstalling that plug.
When I am all done I have pumped about 12 oz of lube into the case.
Had the same experience last year.
What is up with this ??
Could I actually have the 3 1/4 inch gearcase with front and rear vent plugs like the 4 1/4 inch model ? I don't have a set of calipers to accurately measure the case and am basing my expectation on the presence of the front and rear vent plugs in my gear case. The shop manual shows only one vent plug on the 3 1/4 inch gearcase and my unit has 2 vent plugs.
People I have asked have said not to worry. If lube comes out the vent holes the darn thing is full. Oh well,,,,,but then again are we sure ??

 

[mikeneal]

Re: Gearcase lubricant capacity ? Manual wrong ??

I am no expert on your motor, but sure sounds like air is trapped somewhere, I would run a short while with in flush muffs and then make 100% sure still full. 12 oz sounds like not much oil.

QUOTE=oldtortuga;1901483]Mercury 60HP 4 Stroke EFI Year 2004-2005 with (I think) 4 1/4 inch diameter gearcase. I know it is not the Bigfoot.
Book says capacity is 24 oz.
Every time I change this lube it holds only 10 - 12 oz.
I carefuly follow the directions about leveling motor, allowing to drain completely, refilling til overflow at front vent plug and then reinstalling front plug then filling til overflow at rear vent plug and then reinstalling that plug.
When I am all done I have pumped about 12 oz of lube into the case.
Had the same experience last year.
What is up with this ??
Could I actually have the 3 1/4 inch gearcase with front and rear vent plugs like the 4 1/4 inch model ? I don't have a set of calipers to accurately measure the case and am basing my expectation on the presence of the front and rear vent plugs in my gear case. The shop manual shows only one vent plug on the 3 1/4 inch gearcase and my unit has 2 vent plugs.
People I have asked have said not to worry. If lube comes out the vent holes the darn thing is full. Oh well,,,,,but then again are we sure ??[/QUOTE]

 

[hamit59]

Re: Gearcase lubricant capacity ? Manual wrong ??

Hi
The non big foot motors look to have 2 vents also on the left side
Big foot motors have a vent screw on both sides. I never really noticed this before so having both on the yard right now. I had to go check for myself.
Then I pulled up the parts break down to confirm. You most likely have a non big foot motor. Which would mean you only need 11.5 oz to fill up you lower .