Starting Help - 1973 Chrysler 85hp Outboard

[mikezitt]

I have a 1973 Chrysler 85hp outboard that would start after a few tries and run fine at high speeds. But it was consistently stalling at low idle and running speeds. Attempting to fix this, I decided to replace the fuel filter diaphragm which looked to be the original. It was distorted and had some stress marks around the edge of it.

Everything back together and now it fails to start. Correction, I got it to start twice for a brief period but then nothing again.

Nothing else has changed to my knowledge. Is it possible that I installed it incorrectly? Could I have put the diaphragm on upside down, or got some debris in the line?

The engine turns over all day. Plugs are new and I have spark. Cylinder 2 had some oil fouling which I hoped to resolve with the new diaphragm. It has new fuel and it flows to the fuel pump and fills the carburetor bowls.

I have scoured the iBoats forum for similar issues with no luck. Any suggestions or thoughts will be appreciated. Thanks in advance!

 

[Frank Acampora]

Re: Starting Help - 1973 Chrysler 85hp Outboard

The diaphragm only goes on one way--you can not install it incorrectly. Well, correction: you would be surprised at what people have done to these engines. I suppose that if you really wanted to and tried really hard, you could get it on incorrectly. LOL

Anyway, Did you replace the inlet and output hoses on the correct nipples. If your pump is mounted on the bypass cover, then the black plastic cover is the fuel inlet to the pump and the screw in nipple behind it is the output to the carbs.

If you have the glass bowl type, then --Phooy---- It's been so long I don't remember and I don't even have one to look at. But the top two nipples are the impulse hoses from the block. The output is always the nipple on the smaller section of the pump.

 

[mikezitt]

Re: Starting Help - 1973 Chrysler 85hp Outboard

Thanks Frank for the good response. It would for sure be a trick to have rotated the fuel diaphragm incorrectly. I was thinking that I might have reversed the gasket and the diaphragm. Top and bottom. Is it possible that flipping those could cause the problem?

I will double check the inlet and outlet hoses that I replaced. I remember that the larger section of the pump hose went to the nipple that was higher and the smaller section went to the lower one on the engine.

And yes, it dose have the glass bowl. Good memory. It's kind of nice seeing right away if you are getting fuel to the pump.

 

[sailingwest]

Re: Starting Help - 1973 Chrysler 85hp Outboard

Hi there, I had the same problem after replacing diaphram in fuel pump.you might want to strip and clean your carbs as you may have blocked or partially blocked idle jets this would also cause the symptoms of your original problem. Jim B