1970 johnson 25 hp 25RL70E

[jdt]

@ stupid questions. One, Is all 80-90 lube the same as long as it has
the GL-5 rating on it? Can I use regular 80-90 that is packaged for a differential in my boat? And second what spark plugs should I use in my motor? I am finding conflicting answers.
Thanks,
Jdt

 

[jbjennings]

Re: 1970 johnson 25 hp 25RL70E

I'm thinking champion J4-C on the plugs. I don't have a manual for that motor, though. J6-C if you're doing a lot of trolling.
You can use the 80w-90 but I'd get the marine kind which has an additive that will help save your lower unit in case a little water gets in. You can use regular 80w-90 but I like the extra security of the marine brand. I use walmart supertech marine lower unit lube and it seems to work fine. The price difference isn't much.
JBJ

 

[jdt]

Re: 1970 johnson 25 hp 25RL70E

ok. I will go with the the j6j"s
jt

 

[tashasdaddy]

Re: 1970 johnson 25 hp 25RL70E

http://www.boatsetup.com/SparkPlugChart.pdf