TWIN 70HP EVINRUDES

G.W. Salm

Recruit
Joined
Aug 29, 2002
Messages
1
I have a 22' Sisu Lobsterboat powered by two 70hp<br />Evinrude outboard motors. The boat was new in 78<br />so I think the engines have to be about that age<br />too. The model numbers are F70ELCIM. The problem I am having is with the port engine. It will run fine for a couple of minutes and then abruptly drop the Revs from lets say 3000 to 2500. After<br />running at partial power for 2-5 minutes, it will recover abruptly, jump back to 3000 Revs only to do the same thing again. I have a mechanic that<br />winterizes the engines but he has not been able to fix this problem. Is it electrical or fuel related? What should I look for (at)? I don't have a comprehensive manual for these engines and only have the Owner's-Operator's Manual for the<br />E70ELCI's. Location of boat, Shelter Island NY. The odometers read about 700 hours. Help please! :confused:
 

Bear

Lieutenant Commander
Joined
Mar 1, 2001
Messages
1,627
Re: TWIN 70HP EVINRUDES

1981 - CI, so they are a few years newer than the boat.<br /><br />You need a manual. It is worth it.<br /><br />Fuel or electric, that is the big question. I hope it is fuel related. Less expensive.<br /><br />Try pump the primer bulb when this rpm drop occurs. Is is firm already or does it pick up?<br />I don't think it is the fuel pump, but some fuel restriction. Fuel tank pickup, or in the carbs. Drain the fuel bowls in a clear and clean bottle. Check for dirt and water. <br /><br />Try that and tell us more. Part two is the electric section...<br /><br />Good luck!
 
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