1970's 45hp chrylser overheating

[fishinginmyboat]

I'm having overheating problems with a late 1970's 45 hp chrylser outboard. It runs great when cold. There is water leaking inside the cover. Some water sprays out of the exaust. This motor has not been run in 8 years. There is also some oil or gas leaking out all the time in the water. A watery/oil mix is leaking out of the small drain/vent holes in the lower unit. How can I tell if the water pump is working? Is the head gasket possably blown? It's compression 100psi. in both cylinders. Any help would be great. Thanks.

 

[scotiany]

Re: 1970's 45hp chrylser overheating

I would remove the LU and check the impeller closely. It could have dry rotted and become brittle-and useless. Could be a stuck thermostat but, I'd go with the impeller first. Take a picture of the union on the shift rod before you disconnect. That way you know about where to adjust it to. Make sure the water tube is aligned when you reinstall. Compression is a little low but, at least both cylinders are in the same ballpark. It could also be your gauge. While you have the LU off, you should change the seals. NAPA has a kit for this about $15. Also, if it were me , I'd change the fuel pump diaphragm and soak and rebuild the carb. Parts for both at NAPA for about $25.

 

[eurolarva]

Re: 1970's 45hp chrylser overheating

The watery oil mix stuff is normal. YOu are talking about the two holes on the starbord side of the lower unit. You are probably running a little on the rich side. Do everything scotiany says . NAPA part numbers are 18-7037 for the carb kit and 18-7806 for the water pump kit. Also get two L82C champion plugs. They are about 2 bucks a piece and they replace the L4J plugs chrysler recommends.

 

[fishinginmyboat]

Re: 1970's 45hp chrylser overheating

Any ideas about the water being pumped inside the cover?

 

[eurolarva]

Re: 1970's 45hp chrylser overheating

What cover you talking about. the covers to the lower unit or to the actual motor on top. The two small holes in your lower unit above the vent plug is for exhaust and water. When you take your motor out of the water you will see it dripping and it is normal. When you stop your motor in the water you will a lot of times see gas rings float to the top. If you idle a lot it is worse. This is a rich condition and is normal for chryslers. <br /><br />If you are concerned about your lower unit leaking remove the drain plug and take a small sample of the oil. It should be dark brown or amber colored. If it is milky white or water comes out you have a seal breach in the lower unit and will have to get it fixed. See attached photo for drain plug location.<br /> lower unit

 

[fishinginmyboat]

Re: 1970's 45hp chrylser overheating

The water is in the motor cover. Seems to be coming out the bottom rear of the motor, but not real sure. I've never worked on a boat motor before, does the water flow through the head? I figured it does, thats what leads me to belive it might be the head gasket. On this motor the exhaust comes out above the water level, where should the water come out? The exhaust has some water coming out with it.

 

[rbruce63]

Re: 1970's 45hp chrylser overheating

Water is coming from the exhaust plate and cover gaskets. Replace them and clean the exhaust plate from carbon build up.<br /><br />Make yourself absolutely certain that the water pump is correctly rebuilt, sealed and seated. I scored the pistons of my "new" Chrysler by starving the powerhead from a good flow of water.<br /><br />Be absolutely clear that the thermostat must be changed. It could end up stuck and you will be an unhappy boater.<br /><br />Get a repair manual or better a trusted mechanic that nows Force/Mercury and perhaps Chrysler motors.