Just a quick question I had about my lower unit oil.  First off I have a Johnson FastStrike 150. I changed the oil back in October and put Johnson lower unit oil in and I think it was in the neighborhood of 24-28oz. bottle.  My question is, is it full when it runs out the top plug?  The bottle I put in there did not get it to run out the top hole.  Do I have enough or do I need to add more?

Also I read the bottle and it said to put the oil in the bottom plug and use the top as a vent, how to yall keep the oil from running back out the bottom when you go to put the plug back in there?  Why cant you just put the bottom in after draining and just put the oil in through the top plug?

Thanks for the help!

You are correct. The lower unit oil level is full when it comes out of the top hole (vent plug).

To change your lower unit oil.

Place a pan under the lower unit. Remove the lower drain plug, remove the upper plug and drain the lower unit. Connect your fill tube to the bottom drain plug, add lower unit oil until it comes out the top vent hole. Leaving the fill tube connected replace the vent hole plug, then remove the fill tube and replace the lower drain plug, your done.

To add lower unit oil.

If you need to just add fluid. Place a pan under the lower unit, Remove the lower plug and connect your fill tube, remove the vent plug, add lower unit oil until it comes out the vent hole, replace the vent hole plug, remove the fill tube, replace the lower drain plug and your done.

When changing your lower unit oil you should make sure the oil does not have a milky look to it. If it does you most likely have a worn prop shaft seal and it should be replaced.

The reason you should never add lower unit oil through the vent hole is that it will trap air making impossible to fill.

The oil should run free out of the top hole while filling it from the bottom hole. Here is rthe way to do it.

Remove the vent plug (top) then remove the lower plug and drain all the fluid out. Take notice to the color of it, If it looks real milky, you have a bad seal in the lower unit that needs to be fixed. After it's drained, start filling it from the bottom hole, I know it's sounds stupid, but this will force all the air out the vent hole. Once you see a pretty steady flow of fluid coming out the vent hole, squeeze in a little more and hold the pressure of the tube. Insert the vent plug, this will create a vacuum allowing you some time to replace the drain plug. Some oil will come out but very little. It needs to be full. Also don't mix up the plugs. the drain plug has a magnet on it to collect any shavings from the gears. There should be a very small amount of shavings on it after some good use.

Hope this helps

Rob

That motor as well as many other OMC's need exactly 33oz yes 33   1 bottle and and bit from another.  I also recommend Amsoil synthetec lower unit oil. will mix with water and still protect and some claim and extra 100-200 rpms. I can confirm that if i spin my prop when it s under 45 degrees it does spin much easier than with regular lower unit oil.

Thanks abunch guys for the help!!!! ;D ;D