74 65 HP 3 cyl runs 10 minutes. then loses power

cheapthrills

Cadet
Joined
Dec 8, 2008
Messages
12
Carbs rebuilt, fuel pump diaphragm replaced, new plugs and tune in June, 08. Ran fine all summer. Took it out in September and ran for 4.5 hours fine and then began a high speed miss. Would run but not at open throttle. Motor picked back up after 10 minutes or so and then laid down again.

Have had it in the water 4 times since then and all 4 times it ran fine for 10 mintues and then crapped out, sputtering but running with no power. Sometimes it will run ok after about 4 - 5 imutes and then it craps out again. Other times, once it craps out, it just stumbles and runs but not well.

This past weekend, drained fuel out of carbs, drained fuel from tank, blew out fuel lines, cleaned filter and put in fresh 93 octane fuel and oil (50:1) and she did the same thing. Ran great for 10 minutes and laid down.

I am at a loss. Any ideas??:confused:
 

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: 74 65 HP 3 cyl runs 10 minutes. then loses power

If you have low battery voltage the ign. system will fail.
 

casi77

Petty Officer 2nd Class
Joined
Mar 13, 2006
Messages
122
Re: 74 65 HP 3 cyl runs 10 minutes. then loses power

i had this happening on my 65hp, turned out the carbs were not rebuilt well by the shop..they had rebuilt them over and was fine afterwards.
 
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