End of season stumble

further

Lieutenant Junior Grade
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Jun 18, 2009
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Just took the boat out of the lake yesterday after about 5-1/2 months and 45 hours of flawless operation except the last two times out i noticed a bit of a stumble or kinda like a miss at high rpm... cruising at 3500 rpm or higher. Low rpm and idle is fine. I plan to winterize and do my usual fluid changes. Did the plugs, wires and dizzy cap middle of last season- guessing about 60 hours ago. Fuel delivery issue maybe? Fuel pump new about 85 hours ago.
thoughts?
 

alldodge

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Staff member
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Mar 8, 2009
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Without digging deep into your exact motor, I would check/clean the connectors of the crank sensor, cam sensor (if there) and then check battery cables both ends. Something may have a bad connection
 

further

Lieutenant Junior Grade
Joined
Jun 18, 2009
Messages
1,031
Just took the boat out of the lake yesterday after about 5-1/2 months and 45 hours of flawless operation except the last two times out i noticed a bit of a stumble or kinda like a miss at high rpm... cruising at 3500 rpm or higher. Low rpm and idle is fine. I plan to winterize and do my usual fluid changes. Did the plugs, wires and dizzy cap middle of last season- guessing about 60 hours ago. Fuel delivery issue maybe? Fuel pump new about 85 hours ago.
thoughts?

Thanks - will try. Also forgot to mention two other weird things... I noticed the voltmeter gauge started showing lower than usual - normally read around 13v and the last two times it was reading around 11 or just under... seems unusually low. And the temp gauge is showing cooler than normal although I think this is likely attributable to the cooler lake water.
 

alldodge

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Staff member
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Mar 8, 2009
Messages
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Thanks - will try. Also forgot to mention two other weird things... I noticed the voltmeter gauge started showing lower than usual - normally read around 13v and the last two times it was reading around 11 or just under... seems unusually low. And the temp gauge is showing cooler than normal although I think this is likely attributable to the cooler lake water.

Think your motor is stumbing because voltage is low. The higher the rpm the more current is needed. If there is a bad connection, voltage will drop due to resistance (bad connection), or alternator has an issue
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
The only time it draws power is when it starts, then the alternator takes over.
Test the charging system.
Meter at the battery, check voltage, start, then recheck the voltage.
Load test the battery. Hygrometer?
Check for water in the fuel?
Setting for 5 mo can cause condensation.
 
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