No Power Under Throttle - only happens intermittently

[Newbie0811]

All, I have been reading a number of posts from others that seem to have the same problem we are having, but we have a slightly different issue that I have not seen in the other posts.. We have a 79 Mercury 115 outboard. Like the others, you hit the throttle and the boat doesn't get above 5 to 10 mph. Starts fine, idles fine. The difference is that our problem is intermittent. At time the engine runs great. Yesterday we had it out, couldn't get it up to speed. After about 10 minutes it takes off and runs 40 mph like a champ. Stopped to gas up and have lunch at a marina. Head home at 40 mph. That night we take it out to fish and nothing. Stuck at 5 - 10 again. Just had a tune up, new plugs, carburetors cleaned, changed the fuel filter etc. Any thoughts would be greatly appreciated.

 

[Faztbullet]

Re: No Power Under Throttle - only happens intermittently

Need to check that all cylinder have spark when its acting up as it sounds like a stator is dropping one side of ignition....

 

[Newbie0811]

Re: No Power Under Throttle - only happens intermittently

Thank you. Appreciate the response. It ran great all day yesterday. Seemed to struggle a little bit getting up on plane, but once it planed out no problems at all. Crazy. They always say that the cheapest thing about owning a boat is buying it

 

[Chris1956]

Re: No Power Under Throttle - only happens intermittently

Maybe your idle mixture is s bit lean? Richen the top carb 1/8 turn and see if she is better. Do you have six coils on the motor or a distributor?