1972 mercury 800 thunderbolt

[martinezalfo]

I purchased a 1972 merc thunderbolt which I was told sat for about a year I rewiredthe whole internal harness and changed the rectifier now when I tried to start it the first time on thr third key turn she fired right up but reved way to high like it was on full throttle turned her off emediatly this happens every time I try to turn her on,can anybody help me on this,Thanks

 

[b0horman]

Re: 1972 mercury 800 thunderbolt

mine did this after i rebuilt my carbs. the problem was i didn't put the throttle butterfly spring on one of the carbs corretly. What was happening was 1 carb was closed and 1 was WOT. i would check to see if your carb butterfly's are closed at idle.

 

[General Leak]

Re: 1972 mercury 800 thunderbolt

Sorry to jack this thread, but...I have this motor and also a question. I can not get any spark. The coil is not getting power. I have 12 v to the white and red , and over 10v to the brown for the trigger,while cranking. I get 71 ohms between the white connector on starboard side and the brown connector on the port side. The thing is, saturday, it started. I let ti run a few min in a large barrel of water,then shut it down. Now it will not spark at all. I did the trouble shooting from CDI page, whats next?