24ft 06 Bentley cruise with a Mercury 150 readings

[Caseyjoe]

Ok for those of you who have helped me a great deal with this project, you wanted to know what my 06 Bentley cruise 240 with a 96 Mercury 150 xr6 would do with the high five stainless 21 pitch prop on it. Well it's fantastic out of the hole but as soon as it turns it is terrible. Top speed is 21 gps and wot is 3500 rpm. All it will do with 6 people on board, one on the tube and the canopy up. I hate to trade in that beautiful prop but I need something different. Any suggestions?

 

[clemsonfor]

Yep like we all predicted your going to need like 13 or 15 pitch prop possibly but also you might have something else going on cause isn't the rule of thumb 200 rpm per pitch? A 15 would only give you like another 1000 rpm which would only be 4500 which is still too low unless like we all said it is just so over propped that it magnifies the torque issue and we can't even get into the rely you need t be.

 

[Caseyjoe]

Also just put another tach on. Have no clue where to set it. Any clue about which setting it needs to be on? I set it where the idle was 1200 rpm.

 

[MH Hawker]

you set the tach by the pulses the motor puts out

 

[Caseyjoe]

I'm new here hawk. Never took the pulse on an engine.

 

[NYBo]

Mercs of that size and vintage have 12-pole alternators, I believe. But post this question in the Mercury & Mariner Outboard sub-forum.
http://forums.iboats.com/forum/engine-repair-and-maintenance/mercury-mariner-outboards

 

[MH Hawker]

the charging alternators puts out AC pulses, its different on each motor and you set the tach to match and it works, their is a little dial on the back of the tach and run the wheel around a few times to polish the contacts before the final setting the dial has 4 to 12 markings, it counts the pulses to show RPM

 

[ahicks]

Also just put another tach on. Have no clue where to set it. Any clue about which setting it needs to be on? I set it where the idle was 1200 rpm.

What brand tach is it? Some tachs are set directly according to pulses/poles, the other uses a corresponding number that has nothing to do with that. Usually has a tiny chart sticker that's not always real easy to read. If it came with no directions, you'll have to go to the tach manf web site.

Prop size is a crap shoot/best guess. Betting a 13 or a 15" pitch is where you end up.

 

[Caseyjoe]

Nothing is ever easy on a boat. While working on this thing I've been watching a show called The Curse of Oak Island where two brothers continue to hit dead ends looking for treasure but for some reason they continue to throw more money at it. I think I'll name this boat oak island if I ever get it done. Thanks guys

 

[Caseyjoe]

Got it. Mercury told me that for a 06 Bentley 24 ft 2log setup with a Mercury 150 xr6 pushing it I need setting 6 on the tach and the black max 16x14 prop.

 

[clemsonfor]

Nothing is ever easy on a boat. While working on this thing I've been watching a show called The Curse of Oak Island where two brothers continue to hit dead ends looking for treasure but for some reason they continue to throw more money at it. I think I'll name this boat oak island if I ever get it done. Thanks guys

Love that show. It's not the current season now it's on in the winter. Seen every season. That's one heck of a legend on that island

 

[clemsonfor]

Got it. Mercury told me that for a 06 Bentley 24 ft 2log setup with a Mercury 150 xr6 pushing it I need setting 6 on the tach and the black max 16x14 prop.

The boat and toons and size has nothing to do with the tac but everything to do with the prop

 

[Dusty78]

Nothing is ever easy on a boat. While working on this thing I've been watching a show called The Curse of Oak Island where two brothers continue to hit dead ends looking for treasure but for some reason they continue to throw more money at it. I think I'll name this boat oak island if I ever get it done. Thanks guys

ve been watching as well awesome show and lots of money spent and that's how I feel on my project as well one step forward two steps back lol

 

[rickdb1boat]

Mercury said to put it on 6.