Chrysler 12.9 hp

[Greg O.]

I just aquired a Chrysler 12.9 hp motor. The price was right. I don't know anything about the Chryslers. First off, what is the proper gas oil ratio? Second, I would like to run it off a Johnson tank using a OMC single line fitting. Has anyone else done this? Or should I plumb a Chrysler fitting to an OMC and use it as an adapter? Just currious what others have done.

Are there any other quircks I shshould know about this motor?

Thank you in advance.

 

[jerryjerry05]

If it doesn't have a sticker/ tag stating it needs 100-1 ratio then 50-1 or 6gal to 1 pint.
It doesn't make any difference what tank or squeezie or lines.
The fitting, since it's old might need replacing (the rubber dries and can suck air),
Any combination of fittings will work.
Just remember the simpler the better.
Install a filter between the pump and carb or the tank and pump(better).
Wal-mart sells a Fram in line. G-2, G-3 or G12 depending on hose size.
These smaller Chrysler motors have been a good motor.
Just keep them out of the mud, sand and rocks.
Check on the gear oil after using.
Not many placements out there.
Post the model# and serial# and we can figure out the year.

 

[Greg O.]

Thanks Jerry for the info. Its always fun to bring an old motor to life.

 

[Nordin]

The year is 1971, 72 or 1973. Chrysler only made the 12,9 Hp in those years. Then the 12,9 Hp became 15 Hp.

 

[Frank Acampora]

Gas to oil ratio is 50 to 1. The 12.9 was in the 9.9 to 15 family and many parts are swappable. Since the male fuel fitting screws into the lower cowl, you would be best buying a female fitting and either attaching it directly to the fuel line or, assuming you still want to use the Johnson, use an adapter utilizing the Chrysler female fitting and an OMC male fitting.

 

[steelespike]

Essentially a 50:1 ratio but with a proviso of 25:1 for severe service and break in. I assume that's something like a boat and weight it can't plane out.

 

[moving violation]

Must be something in the air...I also just acquired a '71 12.9 this past weekend. The original owner (friend of the family) gave it to me...used very little and seems to be in really nice shape. I'll be looking for/replacing the impeller before I try starting it. I'll stay tuned to this thread...thanks already for the info...

 

[Greg O.]

Thanks everyone for the input. I am looking forward to making smoke from it. I haven't had a chance to even look at it this week. Moving Violation, sounds like you have a nice one. Mine looks a little rough, but has good compression, which is half the battle. Chrysler had nice styling in their day, better then OMC of that era. But then again beauty is in the eye of the beholder.

 

[fishrdan]

Replace the impeller and rebuild the fuel pump, get those old rubber parts swapped out. Probably $30 in parts and a couple of hours of work. Plugs and gear lube is most likely in order too... I would inspect all the fuel lines as that 40 year old rubber wasn't ethanol resistant.