1972 mercury 80hp starting issues, please help me save my baby.

[colinwalsh]

I have a 1972 mercury 80 horsepower 2 stroke outboard. great fast motor for my 17 1/2 foot glasspar.

Issue: was running at 3/4 throttle and motor died, tried to start back up and when the key would disengage the motor would die, making a spinning noise like the flywheel was slipping and not grabbing? The motor turns over strong and we tested compression once home with 100+ on all cylinders. we checked the like to the carbs and there is fuel going to them.

the motor cranks over like it is about to start and then nothing, seems like there is something stalling it from firing. would this be a timing issue?

any help would be much appreciated. thank you

-Colin

 

[Chris1956]

Re: 1972 mercury 80hp starting issues, please help me save my baby.

That is a symptom of a failing ignition trigger. Go to the CDIElectronics website and run the ign test for the distributor ignition system you have.

Be aware that the rotor is not removeable, fragile and cost $200 to replace (not including labor). A trigger can cost about the same, since you need to replace the distributor housing.

 

[colinwalsh]

Re: 1972 mercury 80hp starting issues, please help me save my baby.

That is a symptom of a failing ignition trigger. Go to the CDIElectronics website and run the ign test for the distributor ignition system you have.

Be aware that the rotor is not removeable, fragile and cost $200 to replace (not including labor). A trigger can cost about the same, since you need to replace the distributor housing.

So my friend and I addressed the issue with the trigger ( we think) upon investigation we found some wiring that was anything from acceptable. The wires coming out of the trigger were connected to the main wires by maybe a dozen or so strands, with a very poor tape job. so my friend soldered them together best we could, shrink wrapped them and it looked better than the previous job

....upon firing the motor we found the same issue, the motor would crank hard and strong but the second it wants to engage on its own it sounds like something is slipping out of place, NOT a rough grinding noise but more of a high pitch whine, like a belt has disengaged or something?

we pulled the drain nut to the carbs and found there was fuel in them. compression is also ABOVE 100.. I get my manual tomorrow and will go from there. any and all suggestions are much appreciated. as I do not have the money to upgrade to a different motor, nor do I want to. this motor is strong and still has lots of life left (or lets hope so)

fish on.

-Colin

 

[colinwalsh]

Re: 1972 mercury 80hp starting issues, please help me save my baby.

here is the issue we are experiencing

 

[colinwalsh]

1972 mercury 800 ISSUES----VIDEO INCLUDED__please help

1972 mercury 800 ISSUES----VIDEO INCLUDED__please help

here is a video of the issue I am having with my motor. It dies at 3/4 throttle one week ago. replaced plugs, good spark, compression at 100+psi on all cyl. carbs are clean. carbs are getting fuel. fuel is new. mixture is correct.

 

[Doc279]

Re: 1972 mercury 800 ISSUES----VIDEO INCLUDED__please help

Re: 1972 mercury 800 ISSUES----VIDEO INCLUDED__please help

Sounds like it is out of time to me. Check the distributor belt - I bet it is missing teeth. It will still spark - just at the wrong time.

Just my guess

 

[Way Far North]

Re: 1972 mercury 80hp starting issues, please help me save my baby.

That whining sound, sounds like the starter motor disengaging under load. Its pretty normal. Most times you don't here it because the motor starts and the bendix on the starter freewheels briefly before disengaging.

 

[colinwalsh]

1972 mercury 800 ISSUES----VIDEO INCLUDED_what is causing the motor to not turn over?

1972 mercury 800 ISSUES----VIDEO INCLUDED_what is causing the motor to not turn over?

https://www.youtube.com/watch?v=DmwOMweagtg

 

[Oldcraneguy]

Re: 1972 mercury 800 ISSUES----VIDEO INCLUDED_what is causing the motor to not turn o

Re: 1972 mercury 800 ISSUES----VIDEO INCLUDED_what is causing the motor to not turn o

Have you tried opening the throttle some? Its obviously got spark, and trying to run, sounds like it just wants a little more gas/air

 

[colinwalsh]

Re: 1972 mercury 800 ISSUES----VIDEO INCLUDED_what is causing the motor to not turn o

Re: 1972 mercury 800 ISSUES----VIDEO INCLUDED_what is causing the motor to not turn o

Have you tried opening the throttle some? Its obviously got spark, and trying to run, sounds like it just wants a little more gas/air

yeah I have tried that in the past, we checked compression, had spark on all 4 cyl with good spark off all plugs, no fouled plugs. I was running at about 3/4 throttle and it went out, and we had this issue ever since. I really do not want to replace this motor nor do I have the money to do so. It has been a champ and ran flawless prior to this issue. any help is much appreciated.

thank you

 

[colinwalsh]

Information on why my 80 hp will not turn over? VIDEO INCLUDED. thank you!

Information on why my 80 hp will not turn over? VIDEO INCLUDED. thank you!

 

[racerone]

Re: Information on why my 80 hp will not turn over? VIDEO INCLUDED. thank you!

Re: Information on why my 80 hp will not turn over? VIDEO INCLUDED. thank you!

First try to get you battery tested or fully charged.---------Perhaps the starter needs new brushes.----Perhaps your cables are bad, try jumping directly from a known good battery to the starter.

 

[colinwalsh]

WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

good spark. clean carb. fully charged battery. good compression.

please help me figure this one out! I really dont want to take it to the shop nor can I afford it. I really love this motor she has been very reliable and a strong outboard.

 

[racerone]

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

Needs a new starter.

 

[colinwalsh]

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

Needs a new starter.

would you recommend a good place to pick one up or do you think I should have a shop put one in? thanks for the help!

 

[colinwalsh]

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

also, just out of curiosity, why do you think it is the starter? I am new to boat mechanics and trying to pick up as much as I go along. thanks again for the quick response. people are so nice on this site.

-Colin

 

[racerone]

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

Sorry, I assumed you acted on the response of your earlier post. Still the same today so I assume you need a new starter.----Trouble shooting is still the best path forward.

 

[eggs712]

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

You can find used starters for cheap on ebay.

I would test with another battery before buying a new starter though, as the battery could be bad.

 

[MH Hawker]

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

To me it sounds like a bad connection is not letting enough amp hit the starter, before you replace it, take apart ever one, clean and polish till it shines not matter how good it looks, thats battery, solenoid, and take the stater off and clean where it attaches to the block and the main power lead where it hooks to the block. Then see how it works. 90 % of starter replacements are not needed but when you replace one the new stuff is clean.

 

[colinwalsh]

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

Re: WHY WILL MY OUTBOARD NOT TURN OVER? 1972 80hp merc

To me it sounds like a bad connection is not letting enough amp hit the starter, before you replace it, take apart ever one, clean and polish till it shines not matter how good it looks, thats battery, solenoid, and take the stater off and clean where it attaches to the block and the main power lead where it hooks to the block. Then see how it works. 90 % of starter replacements are not needed but when you replace one the new stuff is clean.

cool,
Thank You so much for that advice i have never even thought about that. I will try that tomorrow and let you know.

thanks again

Colin