Weak spark on a 1996 DT25C

RROBINETTE

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Aug 8, 2006
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DT25C 02507-751171 The motor runs rough on all stages but will run and idle.I took each plug out and grounded to the head bolts and the spark looked weak on all three.Plugs look foul and wet after running.Compression was 130 130 &120.Just hoping its not the cdi but not sure what to do next. Thanks for any ideas, R
 

rodbolt

Supreme Mariner
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Sep 1, 2003
Messages
20,066
Re: Weak spark on a 1996 DT25C

can ya explain how a bad CDI can make weak spark? its an input output storage device. and your test method is not reliable, that system must be capeable of 1/2" gap minimum.
 

deejaycee_2000

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Mar 28, 2006
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3,447
Re: Weak spark on a 1996 DT25C

make sure you have the correct gap on your spark plugs ....
 

RROBINETTE

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Messages
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Re: Weak spark on a 1996 DT25C

RROBINETTE said:
DT25C 02507-751171 The motor runs rough on all stages but will run and idle.I took each plug out and grounded to the head bolts and the spark looked weak on all three.Plugs look foul and wet after running.Compression was 130 130 &120.Just hoping its not the cdi but not sure what to do next. Thanks for any ideas, R
 

RROBINETTE

Recruit
Joined
Aug 8, 2006
Messages
3
Re: Weak spark on a 1996 DT25C

I bought a spark tester and had a 1/2" spark on all 3 wires, new spark plugs and checked the gap ,cleaned the carbs. and checked float levels adjusted idle screws and it still runs rough. It gets loaded up after running about a hour and dies,have to clean the plugs again.I dont know much about outboards, first time I worked on this one but could it be a reed valve or timing issue, just thumbing through the service manual guessing.Thanks again for any help. Russ
 

deejaycee_2000

Captain
Joined
Mar 28, 2006
Messages
3,447
Re: Weak spark on a 1996 DT25C

Coud be your reed valves, but also check your fuel filters, and ventilation at your fuel tank, make sure you have a proper ground, a broken wire can cause a weak spark ..
 
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