View Full Version : Overheat??

April 7th, 2006, 08:56 PM
I have an old outboard aircooled, with water assist cooling system, Chrysler 3.5hp 1 cylinder motor that overheats when not in water, Understandable! But when i put in water it still overheats then the piston locks up, it only runs for about 5 min. before doing this. Help me please.

Thanks Will

April 7th, 2006, 09:23 PM
The old water assisted cooling outboards use a pickup tube thats generally in the propwash...at least my old 2hp Elgin is that way. Make sure there are no blockages in that tube. Also, if you are running too lean a mixture of oil in your gas, you will have the same effect with overheating. I think the old Chryslers were 25:1.

Speaking of lean, too lean a fuel / air ratio causes overheating problems too. Assuming the carburetor is set correctly, the biggest cause of lean running 2 cycle engines are bad seals on the crankshaft, followed by crankcase seals. Most people don't realize that 2 cycle engines have to be air tight to run properly or else you will burn pistons. If your chrysler is oil covered under the cowling, suspect the crankshaft seals being bad.

Have you been over here?? Someone over there can line you up on parts if you need them.



April 8th, 2006, 02:27 PM
if i use one gallon of reqular unleaded fuel how much oil should i put in and what kind.

April 12th, 2006, 01:27 PM
1 gallon of gas = 128 ounces

128 ounces \ 25 = 5.12 ounces of two stroke oil. On old air cooled outboards, I've had good luck with the yellow bottle, Penzoil two stroke oil.

5oz is close enough. If you go to wal mart, you can sometimes find a syringe looking device that is calibrated in ounces. Look in the marine section of the sporting goods area....particularly where the outboard motor oil is. Its specifically designed for mixing up small quantities of 2 cycle gas. If its not there, check over in the lawn and garden section by the string trimmers.


April 12th, 2006, 07:43 PM
Thanks Gsniper