1973 Merc 65hp wont start

[scottyisback44]

Hi all. Im new to boats. I can work on a snowmobile with my eyes closed but boat motors scare the crap out of me. I dont know much about them. Well i bought a 1973 boat with a 65 hp merc on it. I went to look at it in a snowstorm and the guy sprayed some starting fluid in the carbs and it fired up but they shut it off because obviously there wasnt any water flowing in it. Well now its nice out and I decided to pull it out and start it up just to hear it run. It wont start. If I squirt some starting fluid into the carbs it will fire and quit. The primer bulb wont get hard. Where do I start to look and what do I do? Im hoping its an easy fix because like I said. I am a boat moron. Any and all help will be great. Dont leave anything out because I am really not boat smart... Thanks
Scott

 

[Faztbullet]

Re: 1973 Merc 65hp wont start

1) Compression test 1st!!!! 100psi +
2) Spark test
If above is ok..
3) Pull carbs and clean ,clean ,clean, install new gasket set and needleand seats
4) Replace fuel pump diaphram
5) Replace all fuel lines from boat to engine
6) Drain fuel tank(s) and fuel or replace
7) Only use a OEM made primer bulb (Johnson/BRP/Evinrude/Mercury/Yamaha/Suzuki)

 

[scottyisback44]

Re: 1973 Merc 65hp wont start

This is all a great place to start. I just ordered a manual to help me with all of this. Some of the fuel lines have already been replaced. The motor has a new impeller and rebuilt starter. What would keep the primer bulb from getting hard? Air leak somewhere???

 

[ckangaroo70]

Re: 1973 Merc 65hp wont start

Check valve in the primer bulb itself could be bad. If the valve is bad it allows pressure to return back into the tank. Get a good line and bulb rated for gasoline/alchohol. Some of the cheepie bulbs really don't like the ethanol that is in alot of our fuel today and within a year or two...the bulb and line will be stiff as a board. Get a gasoline/alchohol rated one and it will last a long time. Same goes for your fuel pumps on your engine. That engine wasn't really designed to be ran with ethanol in the fuel, but for alot of us and especially us in the midwest...almost all our fuel has some in it. Ethanol can be pretty hard on older motors and can stiffin up the seals in your pumps. So replacing them is a good idea especialy if they have not been rebuilt in quite some time. It really does sound like you have a fuel delivery issue. If you can do the work yourself and have a bit of mechanical experience and a shop manual...you are not looking at that great of expense to rebuild the entire fuel delivery system.

 

[carholme]

Re: 1973 Merc 65hp wont start

Do you have a s/n for the engine?

Here is a Parts Listing:

http://www.crowleymarine.com/mercury-outboard/465.cfm

The Mercury Service Manual is P/N: 90-68647

http://www.ebay.com/itm/MERCURY-OUT...47-/160750854759?pt=Motors_Manuals_Literature

or here is a condensed version of the Clymer manual for you to get started with:

http://web.ebscohost.com/serrc/pdf?...9-a758-7c3f36159468@sessionmgr14&vid=4&hid=10

Download this to your computer soonest as the link is short lived.

Gerry

 

[scottyisback44]

Re: 1973 Merc 65hp wont start

So far I have checked the spark, all 3 cylanders have good spark. Replaced the fuel line from the tank to the motor and changed the primer bulob. The primer bulb will not get hard. Not sure why it will not. It sounds like its pumping gas. The arrow is pointing at the motor. Anyone????

 

[ckangaroo70]

Re: 1973 Merc 65hp wont start

Did you look inside your tank to make sure the pickup line has not fallen off? Also....did you try pumping the bulb with it disconnected to the engine? You can take a phillips screwdriver while pupming the bulb and push in the valve at the end of the line that way you can see how well the fuel flow is when you pump the bulb. Just something to check if you havn't already.

 

[scottyisback44]

Re: 1973 Merc 65hp wont start

OK here is an update. Put fresh gas in the tank. Changed the spark plugs. Drained the carbs. Took apart the fuel filer and fuel pump. cleaned that all up. Finally got the motor running. It sounds great. Put the boat in the water and either controls are backwards or I am. Forward was reverse... Is that suppose to be that way? Also the boat would rev up and sound great but it would go anywhere. It moved but should have been ripping with the RPMs it was turning. Brought it home and noticed that the prop wasnt very tight. Took the prop off and discoved some grease that was like tar.. Is that normal? There was no pin holding anything on and no spot for a pin to go. Is that normal?? I put everything back together and tightened it down. Have to see if it goes tomorrow. Also, how much water should be spraying out? It was spitting out but I thought it should be a stream... When I bought it they said it had a new impeller. Thanks for the help...

 

[scottyisback44]

Re: 1973 Merc 65hp wont start

One more thing... On the controls there is a knob at the front of the controls that turns. Nothing happens when I turn it. Is that for auto trim if it was installed?

 

[carholme]

Re: 1973 Merc 65hp wont start

I'll ask once again, do you have the engine s/n?

As far as your fwd/rev problem it sounds like they installed the LU without the boat being in the same gear as the LU.

Here is a link to the prop shaft. There is no pin as you will see on some other engines:

http://www.crowleymarine.com/mercury-outboard/parts/465_19.cfm

That engine has a thermostat and poppet valve, with the thermostat a 143 degree unit.

Gerry

 

[scottyisback44]

Re: 1973 Merc 65hp wont start

I do have the sn. its 3661873

 

[Moody Blue]

Re: 1973 Merc 65hp wont start

One more thing... On the controls there is a knob at the front of the controls that turns. Nothing happens when I turn it. Is that for auto trim if it was installed?

Um, do you have the MerControl type controller? If so, that "knob" you are turning is an electrical connector for connection of a tach. As you are turning it, you are twisting the wires inside the control and will possibly result in a short circuit. It is not meant to be twisted.

 

[scottyisback44]

Re: 1973 Merc 65hp wont start

yeah thats the type of controller I think. And I will stop playing with that knob now.

 

[scottyisback44]

Re: 1973 Merc 65hp wont start

I'll ask once again, do you have the engine s/n?

As far as your fwd/rev problem it sounds like they installed the LU without the boat being in the same gear as the LU.

Here is a link to the prop shaft. There is no pin as you will see on some other engines:

http://www.crowleymarine.com/mercury-outboard/parts/465_19.cfm

That engine has a thermostat and poppet valve, with the thermostat a 143 degree unit.

Gerry

So obviouslt the thermostat works like a car. once the motor reaches the temp it opens up and circulates more water??? Sorry for the dumb questions, I am trying to learn as I go and the damn manual hasnt came in yet...

 

[ckangaroo70]

Re: 1973 Merc 65hp wont start

When running...the engine should pee a steady stream....or at least it does on my 1979 Mercury 50hp which was not designed to have a thermostat, but perhaps the 1973 does have one(I don't know), but it still should pee a stream when open. Whoever installed your water impeller got something out of line when reinstalling the lower unit which is probably why your shifter is screwed up. As others have said....don't turn the outlet on the front of the shifter. That is an outlet and not a nob. Your prop should be held on by just a nut, but there should be a brass plate that goes on behind the nut and it has a couple little tabs you bend up against the nut to keep it from loosening.