1978 800 mecury

[tiger18th]

I just bought this motor and got it put on my boat. I took it to the lake today and once i got it in the water and was getting ready to take off the motor started sounding funny. it never got up to speed. the sound was like a thumping, not like it was metal. i was thinking it's some kind of fuel problem. and since i'm asking what is the fuel mixture, i was told that it was 50:1 is this true? any help would be greatly appreciated.

 

[achris]

Re: 1978 800 mecury

Originally posted by tiger18th:<br />I was told that it was 50:1 is this true?

Yes.<br /><br />The thumping sound like a piston may have detonated. Pull the spark plugs out and look at them. If any have aluminium on them, we have a rebuild to do. Or take it back to the shop you bought it from and have them replace/repair it.<br /><br />Chris..........

 

[tiger18th]

Re: 1978 800 mecury

I went out and pulled the spark plugs out and there was no sign of any metal on the plugs just a lot of build-up. However, one of the plugs was only twisted in around three or four threads. I'm going to replace all the plugs is there is anything else that I could do? The sound I was talking about, the more I think about it, it was more of a intermittment like it couldn't get power. Thanks

 

[achris]

Re: 1978 800 mecury

Do a compression test while you have the plugs out.<br /><br />Chris..........

 

[tiger18th]

Re: 1978 800 mecury

Where do I get the tool that I do the compression test with? I have never done this, is this task hard?