Whats the difference? Adapter plates

[xb03]

What's the difference in an ss promax 1 piece plate and a 260 or 280 one piece adapter plate?
Found out that the early ss promax's had a 2 piece adapter plate. Mercury than switch to the 1 piece plate, promax specific only.

 

[BGohr]

the adaptor should be the same the tuner for the one piece 225 is much narrower than a 260/280 piece

 

[xb03]

I heard the ss promax plate had different cooling holes ect so it would provide more heat for the steel sleeves.

 

[suicidealli]

The 260/drag plates are the same as far as what I have seen... The 280 plate has bigger holes for the water to drain.. Bad idea... I fill them in and redrill smaller.. Just sold a 20" o/s with a pm 1 piece plate, but I didn't look that close. I have heard the exhaust openings are smaller, but can't say for sure.. The tuners are all different. I like the 280 tuner the best besides a diamond tuner... Also prefer dry stacked too, even on my bass boat.. I don't know if it makes a difference dry stacking, an average guy couldn't tell any difference.. A data logger may... The theory is logical, so I do it....
It makes them louder yet, without the water runnning into the exhaust..


Roy

 

[Dave Hensley]

Does the 280 plate have any more thickness or effective length? Heard they did which helped bottom end torque?

 

[suicidealli]

The plate, or the tuner?

 

[xb03fs]

Would a 200 EFI benfit from a 280 or a diamond tuner? I may have the powerhead off this winter to add an Alien cowl?? I have read tuners don't make much differnce

 

[Dave Hensley]

The plate, or the tuner?

Plate. The way the boss extends out where the tuner bolts up. Never measured but heard it was thicker.

 

[BGohr]

The one piece mercury 225 promax adaptor plate I have here is the same as the 280 plate, just has a different tuner. the adaptor plate between a drag and a 280? the drag is machined down and inch where tuner mounts

 

[Dave Hensley]

BG are you coming to Jasper? If so I need to catch up with you.

 

[xb03]

BGhor, pm sent

 

[shaun]

I had a promax with a 1 piece plate and later went to a 260. The promax plate definately had smaller exhaust openings, the water dump holes were alot smaller, and it had smaller studs that mounted to the swingarm.

The studs for the tuner mount were the same as the 260 so any 2.5 tuner should mount up.


Shaun

 

[Fl Boy in ILL]

. the adaptor plate between a drag and a 280? the drag is machined down and inch where tuner mounts

On a drag with it machined down does that effect bottom end but help on top end such as more RPM's. Whats the theory between the 2?

Rick