# 225 Mercury bogging down



## Rotund One (May 19, 2009)

I have a 1997 225hp Mercury on my 21ft Robalo cuddy cabin. Lately, when I am ready to go, and I put the throttle down, the engine will reach 2500 rpm, and struggle. The boat just pushes its way through the water without getting up on plane. I then work the throttle back and forth and sometimes the motor will fire on up to 4000 rpm and I am off. Also, sometimes if I trim the motor up a little, the engine will come back to life and jump up on plane. This problem is not consistent, although, it is becoming more frequent (approx 70% of the time).</DIV> Last week, after running 15 mile back to the bayou, I idled through the no wake, and when it came time to speed back up, the motor would stall when I put the throttle down. I am not sure if these are to seperate problems, or not. </DIV>


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## sosmarine (Sep 28, 2007)

Sounds like you have a fuel issue. Do you have a water/fuel seperator in line? If so check it for water and/or trash. Is this a Carb or EFI motor?


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## ul412al (Oct 2, 2007)

Welcome to the forum! I had 2 of those motors and I would first check the plugs and plug wires. Sometimes they make partial connection and sometimes the other cylinders will "pull" along a dead one.



As for the other problem, do you get any alarms? If the alarms aren't hooked up, then check the oil level on the motor. If it is fine, check (and/or) replace the impeller. If that doesn't work - take it to Kenny!


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## Rotund One (May 19, 2009)

I have a carb motor, along with a fuel/water separator. I have replaced the fuel filter (separator & in-line)and the spark plugs within the last 100 hrs.


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## DOUBLE "D" & LV (Oct 2, 2007)

First, check to see if you loose cylinders by spark or by fuel and make sure that the spark plugs are the correct ones. On those engines, they have CDM modues (coil packs) that will do some strange things. One of them may cause up to all the rest not to have spark, but that bad one will. The stator, or flywheel gear counter may also be acting up. (Usually the stator is an all or nothing item though. This stator has one coil bobbin for each cylinder CDM and could still be intermittent.) I will be glad to look at it, but I am a couple weeks backed up. Once it is determinned if cylinders are dropping out or not, then you can move forward to also check to see if the timing is advancing or not if you do not find a problem with dropping cylinders. As stated earlier, check to be sure your warning system is working so you are not chasing a ghost due to an overheat condition or other item.


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