Mercury 650,65hp Motor Trouble

kellykool

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Jul 10, 2005
Messages
11
I have a 1966, Mercury 650, 65hp, 4 cylinder. When I first put the boat in the water it cranks great. It's idled a bit to low but when you give it the gas it runs great. After just a minute or so it's like it just quits running for a millisecond and then starts running fine again. Then it may lose power for a few seconds and then it restores itself and runs great. I can then turn the motor off and do a little fishin' (which is why I bought the boat) and when I go to crank the boat again it will not even try to fire. I can let it sit for 10 or 15 minutes and then it will crank again (except last Saurday when I had to troll all the way back to the dock). Does anyone have any ideas what may be causing this? I love the boat and motor would just like to get it fixed. I ordered a manual for it, but I am figuring the troubleshooting section is not going to cover this.<br /><br />Thanks Kelly
 

Laddies

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Sep 10, 2004
Messages
12,218
Re: Mercury 650,65hp Motor Trouble

Ck the mecury switch for tilt by disconnecting it from the mag, if that don't help remove the kill wire also to see if the trouble is in the harness or the mag, if that don't help you will need to rebuild the mag--Bob
 

kellykool

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Jul 10, 2005
Messages
11
Re: Mercury 650,65hp Motor Trouble

Thanks so much Bob.. I really apprecitate your help.. I have had this boat for about 6 months and has done this non stop.. Could anyone suggest the correct about of oil to be mixing with the gas? Where would the Mag be located? Sorry Guys, I am female and don't know enough.. Lots of questions.. Thanks Kelly
 

Laddies

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Sep 10, 2004
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12,218
Re: Mercury 650,65hp Motor Trouble

The gas mix is 50 to 1, if you don't know where the mag is Kelly you should seek some help so you don't get into a problem--Bob
 

danielar

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Sep 13, 2005
Messages
4
Re: Mercury 650,65hp Motor Trouble

Kelly, were you able to find the problem. My proble is simmilar.
 

kellykool

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Joined
Jul 10, 2005
Messages
11
Re: Mercury 650,65hp Motor Trouble

MacGyver,<br /> Yes we did find the trouble.. It was all caused by a burnt piston.. We have now replaced the piston and rings.. Putting things back to gether and hope to have it in the lake this weekend..
 
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