Missing cooling part on Chrysler 20HP?

[papi]

Hello!

I have just bought an old Chrysler 20HP out board motor. It starts and runs perfectly up to about 10 knots. If I go any faster the cooling water stops flowing abrubt. It has been suggested that there might be a missing part located at the cooling intake (number 3 in the picture). All suggestions and ideas welcomed. /Thanks Patrick

 

[jerryjerry05]

Re: Missing cooling part on Chrysler 20HP?

Sounds like the first thing you should do is change the impeller.Check water tube for clog.
Need a closer pic.Jerry

 

[papi]

Re: Missing cooling part on Chrysler 20HP?

Hi and thanks, here comes a closer pic. According to the seller the impeller is new. The bolts are new and the cooling water flow is high until it stops above 10 knots. Running the motor for 20 minutes (on low speed) the temeperatur of outlet water are about 40-50 degree celsius or 110 farenhaiet. The engine sits on a Vator 12 R boat.

 

[eurolarva]

Re: Missing cooling part on Chrysler 20HP?

A couple things could be happening and my response is probably not going to give you any assurance. At higher speeds it is possible that the water is just going out the exhaust into the water and that is why you are not seeing it, however it could be a defective or improperly installed impeller. I have seen the brass inserts separate from the rubber and it will work at idle but not at operating speeds. It is possible the vanes are pointed the incorrect way or the driveshaft impeller pin is not installed correctly. If it were me I would get a manual, take the lower unit off and try and see what is going on.

 

[papi]

Re: Missing cooling part on Chrysler 20HP?

Tanks for your thougts eurolarva. I do think that the motor gets to hot at high speed so that leavs it out to the impeller (or if the motor dont fits the boat in some strange way.)

If I decide to dismantle the the rigg/impeller I do it with a camera in reach for you guys to comment. /patrick

 

[Frank Acampora]

Re: Missing cooling part on Chrysler 20HP?

That impeller is a pin drive in a plastic insert. and the pin is only about 3/32 in diameter. Like Euro said above: Drop the lower unit, remove the water pump housing and check for a broken or missing pin.