So I can not find a good description of how Guardian acts when it trips. How does the motor sound, I know you will get beeps but how does the motor act and sound?

It slips, kind of like a clutch, but you`ll never be able to tell. Testing shows the the torque limiting event is 0.095 seconds long. You`ll never know its happening. Thats the beauty of the Drive Guardian!

Send me your email if you`d like the tech brief.

He's not asking about Drive Guardian.

Guardian Mercury Fault electronically restricts power. You will not get full RPMs, and overall the motor will feel slow & sluggish.

Yes not the drive Guardian. I have a constant warning beep and I cant get past 1000 rpm. It acts like its going to die, coughing or flooding kind of thing and as soon as I bring it back it is fine. I know when I have hit the rev limiter in other boats it just like shut off for a second, and in cars the same kind of thing. I just wondered what you would hear from the motor or notice if it was restricting you besides lack of power.

Guardian mode limits the amount of rpms - depending on the ACTIVE FAULT the motor can have 5 % to 90 % available power. Again if your motor is limited on rpms and can not reach max full throttle along with a beeps or a continuous warning horn / beeps, you are in guardian mode of some form because you have an active fault (s).

Do not take this wrong but you are beating yourself up over this. I posted again some info and you need to change your water pressure sensor and read some of the other info posted that might come into play. It might be worth taking your boat in to a mercruiser shop that works a lot 496's. Just saying.

Thanks BUP, I did purchase a pressure sensor. I am just trying to understand it all.

Does the beeper sound before anything else happens as a warning or does the beeper and guardian mode come into play at the same time. I routinely bump the rev beeper when running light but have never noticed the power back off. (Mine's a 525)

I hit send too soon on the last one. I am taking it all in thanks for all the advice just trying to figure it out. I only have a problem easing past 1000 RPM under load it stumble some will not let me go any higher. Revs fine in neutral no problems and I can go from idle to wide-open throttle without any problems either boat runs fine until backdown get close to idle again it starts to stumble and act funny. I get no warning beeps until I ease past 1000 RPM.

I would think if I had a blocked pressure sensor or pressure problem I would have that in both idle, neutral rev and wide-open throttle. The same with the IAC in my mind. The other where thing is that all goes away after a while I can Putz around at 1000, get into it hard so it won't do and eventually it stops doing it.

again sorry for all the posts just trying to figure it out. I want to head the lake with everything I got ready to go to leave no stone unturned before I head out there

All fixed it was the pressure sendor as Diacom said it was. Thanks for all the info and help. I also now know what Gaurdian act like when it happens. We were able to get it to do full Gaurdian (only idle) and after cleaning and checking connections (before just replacing the sensor) got a 90% power with two beeps. I am much more informed now thanks again.

Hey thanks for re posting the fix and in the other thread. I figure if people post possible problem solving fixes then the OP can comeback up and post the exact fix when it takes place so everyone can learn.

Like I said no offense, you were beating yourself up and change the water pressure sensor for starters.