496 HO guardian mode?

[hessdk]

I am running a 22' Velocity with a 496 HO. Even with the drive tucked in and the tabs all the way down, it is pretty lazy coming out of the hole. I noticed the other day when trying to get on plane and at full throttle I was only seeing about 3000 RPM. Once the boat planes it takes off. I know that Velocitiy's have high X dimensions, but this feels to me like the computer is limiting power. Is this part of the computer program for the 496's for warranty purposes? Guardian mode? Any thoughts are greatly appreciated.

[MOBILEMERCMAN]

In most cases the alarm will sound. One example is a short series of beeps every two minutes.. There are different sequences and intervals of tones for different problems. If it is not setting off an alarm and you do not have a smart craft display the best way to find out if it is in fact in a power reduction mode is to plug it in to a scan tool like Mercs DDT.

[hessdk]

Thanks for your reply. I am not hearing any beeps or seeing the red dash light. I do have Diacom Marine software I can use. What parameters should I look for and trend? I swear it feels like the power is being reduced because the engine runs just fine once on plane and at top end. In my past experience, even a boat was slightly overpropped, the RPMs would come up higher than 3000 while trying to plane.

[MOBILEMERCMAN]

If power is reduced it would be evident at top end.

[hessdk]

I know it does not make sense, but I was wondering if the computer program somehow reduces power to keep the engine from overloading the drive while getting on plane.

[MOBILEMERCMAN]

Never heard of such a thing.

[hessdk]

Which specific connector was giving you a problem? Thanks.

[Teague Custom Marine]

Hey Hessdk,

Did you figure out what was going on? The 496's do not make too much bottom end torque, so don't ask for a miracle. Depending on your prop gear/pitch and your boat, they are just lazy. What prop pitch are you running? What is your top RPM with that prop?

If you were in a guardian, you would know! It wouldn't go over about 3,200 RPM and would be beepin at you all the time.

If you think you have guardian problem, take the boat to your local (good) Mercury mechanic and have them hook it up to a computer to see any codes. -Eric


TEAGUE CUSTOM MARINE
661.295.7000
www.teaguecustommarine.com

[Raylar]

If your Diacom is hooked up while you are running and you check the power output percentage value and if its showing 100% at idle up thru full throttle acceleration, then there is no guardian active holding back bottom end power.

Stock programming is like the other 30,000 496's out there, its not perfect but all the other 496's are accelerating just fine!

Merc 496's have excellent bottom end torque from 1500 rpms up thru 4200rpms!
They make over 450 lb/ft. at 3000 rpms and up to 485lb/ft. at 4000rpms. That better than all stock 454's, 502's and a few others like the HP500efi and such!

My initial thought is you need some prop changes to something better than you're using now.

What prop and pitch are you using now and what is your WOT rpm?

I hope your not running captains call or silent choice closed when you throttle up?

Best Regards,
Ray @ Raylar

[Boat Tech]

I am running a 22' Velocity with a 496 HO. Even with the drive tucked in and the tabs all the way down, it is pretty lazy coming out of the hole. I noticed the other day when trying to get on plane and at full throttle I was only seeing about 3000 RPM. Once the boat planes it takes off. I know that Velocitiy's have high X dimensions, but this feels to me like the computer is limiting power. Is this part of the computer program for the 496's for warranty purposes? Guardian mode? Any thoughts are greatly appreciated.Have you had any service work done to your Stern Drive area lately???

There's one thing you might want to consider checking out on your bravo drive to see if it's in the correct position, You should double check to ensure that the "celery stick" is in the correct position.

The "celery sticks" = (the trim insert, Trim Adjustment stick) If the stick is in the wrong position on the newer style bravo drives, it will affect your time to plane immensely.

See number 30 in this link below for an idea of what and where it goes.
http://www.mercruiserparts.com/Show_Pictures3.asp?dnbr=880951002&ivar=images/COMMON/26405.png&inbr=11210&bnbr=90&bdesc=Driveshaft+Housing+and+Drive+Gears

Also see page 3-5 in this next link for directions of how to correctly install the celery stick between the bravo's 1 thru 3 drives.

http://www.boatfix.com/merc/Techbk/97/97hs3.pdf

Hope this helps,Good luck with it.:)