General Questions 1973 Johnson 25 Horse

"Hi Folks,

I am completely

"Hi Folks,

I am completely new to the marine scene and I recently purchased a 73 Johnson 25 horse, model# 25R73A as to catch fish where I live in northern Wisconsin. The motor always takes about 6-8 pulls at the start of the day and one pull all day thereafter. That is okay with me and is not a big deal. I changed the spark plugs and the lower unit oil. The lower unit oil was about 20% or so milky color mixed in with grayish black. The motor shifts fine, but I realize that a seal must need to be replaced. I will get to my question(s).

1. On the lower unit oil, I do not have the money to bring it to have it fixed, so I was thinking of just replacing the oil every month or so, always keeping fresh in there. What do you guys think?

2. From what I have heard, most people running these old Johnsons run 36 or 40:1 instead of the 50:1 as to not scorch a cylinder. Sounds like solid advice to me, but what is the consensus here. I realize that I will have to replace plugs more often, but the NGK B8S only costs 2.19 a piece, so no big deal there.

3. The motor sometimes will stall when you idle down right before shifting in gear. Not a big deal as I usually leave it in forward all the time anyway.

Sorry for the long post! Thanks in advance for the help!

Jon"

"1. Buy a seal kit. Sierra kit

"1. Buy a seal kit. Sierra kit 18-2684 -- about $14, plus shifter o-ring and bushing for about $5 more. It's a bunch cheaper than oil. Whatever seal is leaking, it's going to get worse and it will toast your gearbox, if not from the lack of lube, but from sitting in the gearcase rusting your gears away. Not to mention what'll happen to the gearcase when the temp drops below 32deg.
2. 50:1 works fine. Not sure who 'most people are', but anyone running a richer mixture under normal conditions is wasting their money.
3. When was the last time the points were dressed and gapped ? Cleaned and adjusted the carb? When you do get down to it, make sure you adjust the idle mixture and idle speed while in forward.

Bottom line -- you gotta spend some time and a few $ on maintenance or you'll have an expensive anchor for when you're out rowing your fishing boat."

If you will go and get you tho

If you will go and get you those little gaskets that go behind the fill and drain screws in the lower unit you may just fix your problem with the water intrusion.

Run that engine with 50:1 mix with a 87 octane fuel and make sure the carbs are right and you won't burn those pistons from lack of oil at 50:1
Now as for the plugs. Those ole johnnie rudes do not like NGK plugs. They love to dine on champion plugs. J4C is what the book calls for but I would use a J6C and gap it at 35 or 40 to help with the idle and plug fouling.

Get you a can of sea foam and decarb that little gal and see if she won't run better at idle. If you need directions for decarbing just let me know and I'll give you some instructions about how to do it.
On the lower unit yes you can change it often and keep the mouister down but where you live it gets cold early and stays late so don't leave any water in there to freeze up.