1978 Merc 650 with 65 Hp WONT START

[JesseNKim]

i have a 1978 merc 650 was just givin to me by a buddy and it was on a 73 pacer 18 foot king open bow he also gave to me i charged the battery and tunr key to on position and raised the warm up lever on the mercontrols and hit electric choke button and the choke worked fine but when i turn the key absolutly nothing happen motor doesnt even try to turn over any ideas what to check for he hasnt started it in 3 years?

 

[CharlieB]

Re: 1978 Merc 650 with 65 Hp WONT START

You are going to need a couple of tools, volt meter, test light, remote starter switch.

First time you assume anything, it's going to come back and bite you right in the .........

Check the battery connections, BOTH ENDS, clean, bright and tight, now check the battery voltage, now with a helper check it again as you hit the key, wiggle the shifter in case the starter lock-out switch is misaligned.

Ground the test light lead on a good ground on the motor battery/cable.
Use the test light and test the yellow wire with the red trace that triggers the starter solenoid, does it light up when you hit the key? Does the solenoid click? Move the test light to the starter side of the solenoid, does it light up when the solenoid triggers?

Use the remote starter switch and trigger the starter solenoid, does the solenoid click/trigger now?

This should tell you if you if the problem is in the battery, key switch, or solenoid.

 

[CharlieB]

Re: 1978 Merc 650 with 65 Hp WONT START

Crank this motor over is one thing. It is NOT ready to run yet.

Get it cranking, then test compression, then test ignition, find out if the motor is in good mechanical condition to run, THEN and only then clean the carbs AND install a NEW water pump impeller, you do not want to start it up just to overheat it and ruin it before you even get it into the water.

 

[JesseNKim]

Re: 1978 Merc 650 with 65 Hp WONT START

thank you so much beleive it or not i still have originial 1978 book for the merc 650 and i was just going over the wiring diagram and i believe because the controls are just so old (1973) that the nuetral start switch may be bad if that is bad is there a way to bypass it just to see if motor still runs right?

also if i could ask what would be a great thing to do to motor if it does run good after sitting for 3 years other than .....

Changing water impeller and housing and bolts
Changing lower unit oil
Cleaning carbs
Change spark plugs

Other than that is there anything good to do to motor after sitting so long?

Thanks for the reply and will check tommorow its 11 pm here dont wanna disturb neighbors expect a post tommorow mid day and thanks again

 

[JesseNKim]

Re: 1978 Merc 650 with 65 Hp WONT START

yes i have a compression tester and will be doing a test after i get it cranking once it starts cranking i will test compression to see where i am if they check out ok i will......

Clean carbs
replace plugs
change lower unit oil
and change water pump in its entirety

all this before i try to even start motor like you said dont wanna burn it up before i get to the river LOL

but i just want to get motor squared away before i start working on boat that needs about 1000 dollars worth of restoration which i am very good at restoring boats and inboard outboards but when it comes to outboards only i can change water pump and thats about the extent of my IN THE CASE WORK abilitys i cant do head or anything so if it doesnt have good compression in a cylinder then im giving the motor away and selling the boat for 50 bucks and moving on to next project!!!

i really hope everything is ok though i heard these motors can last forever if taken care of and the boats in decent structual shape just alot of cosmetics.