i got a 75 horse merc and a 9.9 kicker both fore strokes how often do i need to change there oil in there i have never owned a 4 stork and love them but i got a bout 25 houres on the 75 most all short runs i fish small lakes and about 15 on the 9.9 ....... longer runs ..... just a little info on this would be nice thanks a lot


and what kind of oil dose that merc take and any thing elss i should do at this time thanks agin

I got 2 new yamahas last season 150 and T8 kicker, and i think it is the first 10 hours on a new motor they told me, then change it. After that you should be able to go the full season on an oil change unless you run tournaments every week. Normal use should let you run all season on a single oil change, when changed in the fall.
As for what oils? You can use the manufactuerers oil or Amsoil has products that will work great as well.

I'm not sure what the lower unit requires for new, but i only replaced mine after the season in the fall (whole season).

By the way are you "Common Man" or just a fan?

Id say it depends on how much you use it. I change mine and filter twice a year. Middle of summer and end of year. I run Amsoil Marine 4stroke 10-40. Check your manual for viscosity of oil to use.
On lube note also, I change my lower unit at the end of the year with Amsoil.

10 hrs first change. and every 100 hrs after that or once a year. I use Mobil 1. But any good 10w30 will do.

just a fan i think common man would rather be tared and feather then spend a day fishing .....

thanks for the info

We run 50 hp hondas and my dealer told me to change the oil in early july and then at the end of the season.
He also changed us from the suggested 10w-30 to 15w-40.

Everything has run great the past few years on all the motors, so I guess they were right with the changes.

I use Amsoil and change it at the begining and end of the seasonr. I have a 18hp Tohatsu (don't laugh) its the same as a Nissan.
I am definitely not running tourneys every year. Lucky to get out 6 times a year.