Lower unit will not take amount of oil required

[navyblue]

I have a 1978 Johnson 70 hp OB. The manual spcs. says it requires 25.4 oz. of oil. I took the fill and vent plugs off and let it drain completely. Then connected pump and filled with oil. But it only took about 10 oz. before the oil was comming out of the vent hole. I did take off the top, flat head screw, not the middle philips head screw. Any help here?

Thanks, navyblue

 

[alangf]

Re: Lower unit will not take amount of oil required

If you are putting lube in the bottom hole and it is coming out the vent it is full regardless of what the manual says it should take. 24+ oz of lube sounds like an awful lot to me but I could be wrong.

 

[alangf]

Re: Lower unit will not take amount of oil required

I just checked the manual on my 100 horse outboard (not the same brand as yours but similar size gearcase) and it calls for 22.64 oz.. The only thing I can think of is that your gearcase didn't fully drain for some reason. Full is still full. Were you getting clean lube from the vent screw hole or was it dark?

 

[navyblue]

Re: Lower unit will not take amount of oil required

I just checked the manual on my 100 horse outboard (not the same brand as yours but similar size gearcase) and it calls for 22.64 oz.. The only thing I can think of is that your gearcase didn't fully drain for some reason. Full is still full. Were you getting clean lube from the vent screw hole or was it dark?

Yes, I was getting clean lube from vent screw. I think you are right. I'm sure it is full. Thanks for your help!