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  #1  
Old 09-12-2008, 09:24 AM
Machinist Machinist is offline
 
Join Date: Sep 2008
Rep: 10 Posts: 4
Location: US
1974 Evinrude 40H.P.

This motor starts up fairly easy and runs ok at half throttle. When I try to give it more gas it starts to sputter like it is going to stall. It will only run good past full throttle when it is not under a load. I would greatly appresciate any help!!!
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  #2  
Old 09-14-2008, 01:08 PM
Kay9 Kay9 is offline
1600T Master
 
Join Date: Oct 2006
Rep: 279 Posts: 615
Location: Central Coast Oregon US.
Clean the carb. Then check the diaphram (sp?) pump. That will likely fix your probs.

K9
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  #3  
Old 09-18-2008, 09:08 AM
Machinist Machinist is offline
 
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The carb has been cleaned and no difference in performance. The motor runs good at full throttle for 2-3 minutes before it acts up. Do you think it could be the fuel pump like you said before ? The motor runs okay with no load on it. This is my first boat so I have no clue what I am doing!
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  #4  
Old 09-19-2008, 07:15 AM
FAST FRED FAST FRED is offline
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Join Date: Oct 2002
Rep: 700 Posts: 3,208
Location: Conn in summers , Ortona FL in winter , with big dock & room for O'nite stop .
Evinrude ignition coils have a VERY limited life.

New coils and ignition wire will cost little at NAPA, and will help resolve weather it is a fuel problem,

FF
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  #5  
Old 09-19-2008, 09:03 AM
Machinist Machinist is offline
 
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Thanks for the advise Fast Fred. I will replace the coils first, if nothing else at least they will be new.
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  #6  
Old 09-20-2008, 03:39 PM
Kay9 Kay9 is offline
1600T Master
 
Join Date: Oct 2006
Rep: 279 Posts: 615
Location: Central Coast Oregon US.
Yea coils first, then fuel pump. I had to do it all on my 64 OMC, now it runs great. If this dosnt do it you might hae the compression checked.

K9
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  #7  
Old 09-26-2008, 08:43 AM
Machinist Machinist is offline
 
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Location: US
I have replaced the coils but have not had the chance to get it in the water yet. I also found out that the timingwith the high speed jet linkage needs a replacement for the adjustment screw.
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  #8  
Old 09-26-2008, 05:01 PM
dd24skater dd24skater is offline
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Location: Ohio
I would check compresion
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