2015 pontoon with mercury 115hp CT rev limiter

[Clancy12]

Hi, I have a 21ft pontoon with 115 hp CT, had it all summer of 2015 and no problem, last week, I started to notice that 2 time out of 3 when I drive and push it to full trottle, I can^t get my full speed and the motor make a sound that seem to me like it cut off and on..... prop is not damage, changed engine oil not too long ago, pontoon is clean.. need help please

 

[Texasmark]

This can't hurt anything and may lead you to your problem. First of all I don't know what CT means and whether if affects my answer or not. For reference, my last engine was a 2002 90, the 3 cyl version of your engine. The manual for that engine showed a rev limiter (on some models) and it received signals from the rectifier/regulator module via a grey wire, the same color that sends pulses to your tach, also from the rectifier/regulator module. Since some models did and didn't have the module (mine didn't), seems reasonable to me that you can run the same engine with or without it...just unplug it.

So if I were you, I'd look for the rectifer/regulator module....alum 1 ? - 2" square with black epoxy filler mounted on an aluminum plate with some other things with 2 yellow wires, a black, a red large wire and possibly a small red also, and the grey wire. Follow the grey around the engine compartment and it will go to the electrical output connector (that connects to the remote control harness) and somewhere will Y off to the limiter module. Pull the plug and run.

Tell us the outcome.

 

[Clancy12]

Talked to a friend that told me that even If a prop doesn't look damage to start troubleshooting with that, so I tried a new prop and problem is gone, tried again with my prop and can't get to top speed and rpm cuts off @ WOT...