had my boat out today and same damn thing,

[Chico]

i put a new set of plugs in started it up ran good applied some throttle got up on plane, ran up to 7000 like a raped ape then it started to cough and backfire so i backed off the throttle. so i unplugged the red wire from the rectifier in the gray box and tried it and it didnt change anything,still backfired or coughed, it does it pretty consistant when the throttle is wide open so i pulled the choke up just thinking if it was starving for fuel it would recover but all doing that did was made the motor bog down and almost kill,it seems when i first take it out it runs pretty good for a couple of minutes up to 6500 rpm then after like 5 minutes of coughing and sputtering it has a real hard time even getting up on plane, not sure if that is because i put new plugs every time i go out or if there if a fuel issue with the small filters, minnetonka4me showed me yesterday how small those damn things were, so now either i go into the carbs or pull the magneto cover and check for metal shavings like drhonda said, any suggestions? if it was fuel it wouldnt make it back fire would it? everything inside the grey box was very clean and dry as well, im stumped fellas

 

[Dr Honda]

If it was a fuel issue... it would surge. (or die) If it's popping/stuttering... that's electric.

Since you disconnected the rectifier... You have a pick-up issue... or the CDI is giving out.

 

[Chico]

ok... so i gotta go in the mag cover like you originally said, it the cdi the same thing as the mpem or are they different?

 

[Dr Honda]

they are different. The MPEM is the main computer... the CDI is your ignition module. The CDI is what receives the signal from the pick-up coil, and fires the plugs.

 

[Chico]

so i guess tonight after im done eating i better go out and pull off the exhaust and then pull the front mag cover to check the pickup, i suppose there isnt a test to determine if the cdi is bad or not, how much are those cdi boxes? i might just buy one if its easier to replace than pulling the exhaust and the front motor mount, i was hoping to be up and running by next weekend so i could go to lake city for the meet and greet