Trim problem or over-propped?

[taberz 0]

I just bought a 248ls with the 496/B3 setup-my first Monterey and I love it. The boat runs great-once I'm on plane, but seems to struggle at hole shot. I had my two buddies riding in bow to assist take off. That size boat with that size motor shouldn't have issues-right? The props are SS 26p and came with the boat. When I returned to my slip and lifted the boat, I noticed the drive and it seemed (to me) that it could be trimmed down a few more inches-but my trim motor won't allow anymore. See attached photo, taken with my phone so may not do any justice.

 

I asked the Mercury tech at the marina to take a look. He flat out said to drop to a 24p prop set. My concern with that is I could over-rev the motor and lose some top end. He also mentioned a drive spacer to lower the entire outdrive. Any thoughts?

[The MOST 0]

Hello Taberz,

 

What is the model year of the boat and is it the original outdrive from the Monterey factory? Gear ratio of the outdrive is??? Sea level or high altitude boating?

 

In the photo the drive "down" trim appears to be correct. Installation of the intermediate and drive looks balanced. The rams are closed and the gimble is in the correct position.

 

Before you install any alterations to the outdrive such as spacers, try using your Mercury tech's recommendation of 24's, (keep an eye on the rpm's). You will sacrifice some top end but gain the out of the hole shot.

 

Also, your leading edge of the prop looks like it has some nicks and chinks in the photo. It would be a good idea to get that reconditioned.

 

BTW, that photo wasn't bad.

[taberz 0]

Thanks for the quick reply! The boat is a 07 and to my knowledge all is factory as the boat only has 40 hours-no service history with Merc. I have no idea of the gear ratio. I will have my tech get that info and will go with your advice of switching to 24s. I have noticed the nicks but I didn't think that would have an impact on this issue. If so, let me know.

[The MOST 0]

 

The hours on the boat do not have a bearing on whether or not the engine, outdrive or prop is the original...many are stolen and replaced everyday, some boats have outdrives and props installed for use at high altitude and then sold or used in a sea level area, gears and shim kits sometimes changed out.....etc, etc.

 

Your Merc tech is the expert on advice of trying the 24's- he does that everyday. He is your best source of help and information.

[marfi 0]

I just bought a 248ls with the 496/B3 setup-my first Monterey and I love it. The boat runs great-once I'm on plane, but seems to struggle at hole shot. I had my two buddies riding in bow to assist take off. That size boat with that size motor shouldn't have issues-right? The props are SS 26p and came with the boat. When I returned to my slip and lifted the boat, I noticed the drive and it seemed (to me) that it could be trimmed down a few more inches-but my trim motor won't allow anymore. See attached photo, taken with my phone so may not do any justice.

 

I asked the Mercury tech at the marina to take a look. He flat out said to drop to a 24p prop set. My concern with that is I could over-rev the motor and lose some top end. He also mentioned a drive spacer to lower the entire outdrive. Any thoughts?

 

Hi there,

 

Maybe this can help if i understand your question correctly, i´m portuguese and some times just have some problems with tecnic words,

 

Bravo III unit have 2 positions, if you look close you can ajust your sterndrive with the bottom off your boat, i know this because i´ve bought a 4.3 mpi seacore with a bracvo III unit and that spare part didn´t come ( was lots in the transport), and without it the sterndrive could not be concluded, so talk to your mercruiser dealer and see if the sterndrive is in the same line off the bottom off your boat with this foto i can´t tell that.

 

Best Regards