12.9hp Chrysler Lower unit seals

MickLovin

Master Chief Petty Officer
Joined
Feb 18, 2013
Messages
822
Ok, after running this motor for a while I pulled the lower unit oil screws out to check the oil and found it already black and with water in it, after changing it when i got the motor. Looks like I need new seals, so may I ask is it the seal in the water pump housing and the one below the housing I need to worry about or is there more, as I said the oil was black so I am thinking it is coming from those two seals not the prop seal I hope. Have 2 seals on order anyway so I will let you know how I go with this problem. Also at the moment I don't have a manual for this motor, and I am unsure about timing and carb settings etc. Can someone help me out with some basic tune up guide for this or am I better off waiting for a manual.
 

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,428
Re: 12.9hp Chrysler Lower unit seals

On these Engines the timing is fixed. Set the points to 020 in at top of camloob.
Then you can adjust the throttle pick up point. There is a mark at the throttle cam and when the roller is at mark the throttlebutterfly shall start to move.
You adjust it with the screw at the carblinkage to the left. It push at a spring connected to the roller rod.
Set the air/fuel mixture screw about 1-1 1/8 turn out from lightly seated then finetune from there.
 

wickware

Lieutenant
Joined
Jun 20, 2009
Messages
1,286
Re: 12.9hp Chrysler Lower unit seals

1. I have never heard the oil described as being Black due to bad seals vs milky or brown due to the water mixed in the oil.

2. If the oil is black and coming from the L/U only, would that possibly point to more than bad seals? Please attach a Pic if possible showing the black oil.

3. Possibly, I am missing an earlier post since I see a ref to seals other than prop seals.
 

MickLovin

Master Chief Petty Officer
Joined
Feb 18, 2013
Messages
822
Re: 12.9hp Chrysler Lower unit seals

Wickwave, the oil is black out of the holes on the lower unit due to not having been run for a good while, also I have creamy oil in my tank of water and when I had checked the oil in the gear box when i first bought the motor it was dark gray/black, I put new oil in and since then it has come into the tank milky and I had water in my lower untit
So I have 2 problems, 1. out of tune. 2. lower unit seals
 
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