225 Promax Offshore cooling

[Reel Life]

Does the factory 225 Promax OS that uses the one piece adapter plate still have the poppet valve and thermostats installed? Or does it use the 280 set up with no poppet and washers in place of the thermos?

 

[njj502]

I'm not 100% sure but I'd think it would have poppit & tstats. Need a bit of heat in steel bore motors. A 1pc promax plate is pretty rare i think

 

[alc]

I think all of the 15' pro max engines were 1 pcs.

 

[Reel Life]

Thanks for the replys.....They are rare, but I want to use the one piece adapter because I may switch to wing plates and external steering rams. I notice the part number for the one piece adapter for the promax was the same as the 280, but the suffix was different the promax is a T11 and the 280 is a T15....any Idea what the difference is?

Still would like to confirm the need to use the poppet and t stats

 

[Myron]

I think the exhaust ports are smaller on the 225 plate, if I remember right it was basically a 2.4 plate

 

[bullwhipjkg]

running a 1 peice on my promax

washers for a 260 in heads no poppet

round 140 degress temp last time cked

 

[xb03]

Don't use a 280. Get a 2.4bp or a 260. You'll need to plug the drain holes in the adapter plate because they are to big for steel bore motors. Redrill the the drain holes to 19/64(2 holes only), run washers, no poppet, and install diverters in the water jacket. The difference in the promax 1 piece and the others are the smaller holes, to allow higher temps. The earlier ss promax's came with a 2 piece, later ones were 1 piece.

 

[suicidealli]

The 280 plate has the biggest holes.. I epoxy them, and redrill them smaller, even with a 260/280/drag powerhead.

 

[Reel Life]

I know the set for 260s/280s and drags with one piece adapters. But, I thought the factory still runs the poppet and T stats with the one piece adapter on the 225 promax to keep temps up on the steel sleave motor.

 

[suicidealli]

I have seen one, but didn't work on it. I'm sure it came with T-stats, and poppet..

 

[Reel Life]

I think your right Roy. I'm going to start with that set up....

 

[Reel Life]

Got my adapter and the poppet definitely does nothing on the one piece adapter. I going to fabricate a brass insert to reduce the drain holes and use the washers in place of the T stats as recommended. I think they leave the poppet in, but it doesn't do anything.

 

[xb03]

Let us know what the temps are, when you get it running.

 

[kylep390]

I was wondering if you could run the washers and no poppet valve on a 2-piece exhaust plate? The motor is a stock pro max sport 1998 model?

 

[suicidealli]

I wouldn't do it.

 

[kylep390]

Just put in a tuner and a Mod-vp mid, Can I run washers and leave the poppet in?

 

[xb03]

No run the T-stats and poppet with a two piece.

 

[kylep390]

Have you done any mods too yours? Mine is 1998 pro max sport on a XB2003.

 

[Reel Life]

If you don't need the one piece adapter for other reasons like use of external wing plate steering or your going to turn the engie over 7000RPM, My understanding is you should use the 2 Pc adapter, poppet and thermos with a steel sleeve motor. the stock set up maintains temperatures much better. The trick with the one pc addapter and the steel leeve motors is getting the flow right to mainain the engine temperature thru the RPM range and keep the passages full at idle.

 

[kylep390]

Thanks very much:cool