How much lube & what this knob???

[refractory148]

I have a 1998 25HP Johnson Model# J25RECB. I drained the lower unit and would like to know the proper amount of lube to add to refill it properly and what type lube to use. I picked up a quart of "Pennzoil High Viscosity Lower Unit Gear Lube, SAE80W-90, API GL-5 Performance". I noticed there was also a lot of oil that was rated TCW-3 i think it was so im not sure if I have the right one. Also this is a hand controlled motor and on the hand control there is a knob. It is on the very end of the control arm by the throttle. It turns but im not sure what it does or if it even does anything at all. I first thought it maybe an idle adjustment or fuel:air adjustment but it doesnt seem to do anything when turned. Guess I need to go get a manual for this motor.

 

[Hooty]

Re: How much lube & what this knob???

The manual idea is an excelent one. The lower unit has two plugs, an upper and a lower. Remove both. When draining, the top one acts as a vent so the old lube will drain out the bottom. When refilling, pump the new lube into the bottom plug until it runs out the top. Replace both plugs using new gaskets or orings. <br />The Pennzoil Gear Lube you got is fine. The TWC-3 oil you refered to is engine oil, not gear lube.<br /><br />c/6<br />Hooty

 

[Joe Reeves]

Re: How much lube & what this knob???

I believe that the knob that you're referring to, which is on the end of the throttle (tiller) handle, would be the idle stop setting.<br /><br />Turn it clockwise to increase the idle rpms, counter clockwise to lower. I retired before that engine came into existence and I don't have the 1998 book in front of me, however from your explanation as to where the knob is, I can see no other reason for it.