Honda 100 lower unit oil (10hp)

[woodsailboat]

I just cleaned the carburetor on my 80s honda 100 and it's running better than ever. I just bought it and I would like to change the lower unit oil before I test it but I don't know what kind to put in it, can someone help me.

 

[Jon Boat Jim]

Re: Honda 100 lower unit oil (10hp)

SAE 80-90 weight with an API rating of GL-5. There are lots of different "brands".

You can buy it at Walmart, any auto supply store, or at your outboard motor/boat dealer if you want to pay more.

 

[woodsailboat]

Re: Honda 100 lower unit oil (10hp)

Thanks I can't wait to test it. One more thing, the motor was given to me by a friend who never had the time to mess with it and the guy who sold it to him said it had a blown head gasket but when I got all the fuel line's hooked up and ran it it never spit oil and the oil wasn't milky after running it for about twenty minutes so is there any other way to test it for a blown head gasket or did the guy have no idea what he was talking about?

 

[Jon Boat Jim]

Re: Honda 100 lower unit oil (10hp)

A compression test will tell you. The compression should be balanced (equal +/- 10%). You'll find threads on this test in this forum, if you do a search.

 

[woodsailboat]

Re: Honda 100 lower unit oil (10hp)

I will definitely do a compression test but it seems to have pretty good compression. When I cleaned the carburetor I got it to run at such low RPMs you can almost count the rotations.

 

[woodsailboat]

Re: Honda 100 lower unit oil (10hp)

Sorry to keep adding on to this thread but I would also like to know how to disconnect the linkage. I noticed that unlike most outboards the shift linkage does not have an exposed place to unscrew the nuts that connect it so does the linkage just separate when the lower unit is dropped.

 

[isaksp00]

Re: Honda 100 lower unit oil (10hp)

I don't know the 10HP, but on the BF8 (8HP) there is a fitting at the top of the shift linkage rod that screws on to the rod (which obviously is threaded at the top). You have to pull the cotter pin and clevis pin that holds the shifter handle rod to this fitting, and then unscrew it - sort of like a cap. It is very hard to reach to unscrew. If you remove the clevis pin you can pull the LU down maybe 6 to 10 inches before that "cap" keeps it from going all the way, which is enough clearance to change the impeller. I have never actually removed mine, as it is so hard to reach. Maybe someone else who's a Honda expert has a tip on how to unscrew that fitting.

 

[woodsailboat]

Re: Honda 100 lower unit oil (10hp)

Well the water impeller is the only reason I need to disconnect it. So I guess I can just separate the lower unit and the clevis pin and see how it goes.Thanks