High water pressure & low water temp

[transomstand]

Me too Chris. I've sent a note to a guy on Allison owners... he's swapping to a 260 and needs a 1pc plate and it's going on a ProMax mid. Going to try to make a trade with him so I KNOW I have the right adapter plate.

Here's some food for thought.... would the fact that I'm dumping both thermostats out the cowl make any difference? Below 143* the T-stats are out of the picture but since the tell tale is off that line and T'd into the adapter plate where poppit water is channeled I'm thinking that once the poppit opens that is where your tell tale water comes from. This probably won't change much but thinking out loud and wondering....

Something doesn't sound right there. I would not pull the powerhead yet until you rearrange the plumbing. Think in terms of slowing down the exit water, that will keep more heat in the powerhead.

[njj502]

I'm with ya Pete. Again, if I have too much water pressure & no heat I'm obviously flowing water and way too much of it. Jeff and I were talking last night and I'm going to check to be sure my poppit is correct (is there more than one???) and then going to plumb the T-Stats back in like they should be.... hoping this cures it... not that pulling the powerhead is that hard...

[transomstand]

I'm with ya Pete. Again, if I have too much water pressure & no heat I'm obviously flowing water and way too much of it. Jeff and I were talking last night and I'm going to check to be sure my poppit is correct (is there more than one???) and then going to plumb the T-Stats back in like they should be.... hoping this cures it... not that pulling the powerhead is that hard...

There are 3 poppet designs, but I doubt you would mix them up, they look a good bit different. I think you confirmed it's working anyway, by the observed pressure drop. I'm trying to come up with a pic of an unmolested Promax to see the hose plumbing, but I'm pretty sure your just dumping too much water, the closer to original you get it, the better.

[njj502]

I've got the picture in my book.... but... Jeff has it.... that dirtbag

[transomstand]

.... but... Jeff has it.... that dirtbag

He sucks


I've looked at a bunch of photos, looks pretty much like "plain vanilla" 2.5 cooling. Hose between the stat covers with a tee in it, running down the rear, then another tee, one hose out the cowl for a tell tale, the other to the adapter plate, and a hose from the top of the block to the poppet cover fitting.

[njj502]

That's basically what I've found too. My T-stats just dump out the cowl and I have no tell tale. I suppose I need to plumb it in but then I've got more area for water to dump and overcool... I guess this will help my pressure problem tho...

[Capt.Insane-o]

I have a pm in the shop I'll get a pic of later today.

[njj502]

Steal the friggin adapter plate too.

[Go Time]

Nick, where is your pressure gage tied in? Is it in the hose between the top of the block and the Poppet cover?

[njj502]

It's on the exhaust plate in back.

[Go Time]

Where on the exhaust plate? Are you right tap directly into the water pump discharge plenum? That might have something to do with it. Do you have the hose from the top of the block to the poppet cover? This water actuall bypasses most of the block (comes off the top of the supply plenum in the block and is directed to the back side of the poppet and out) and measuring pressure there may show less pressure and this is where the gage is suppose to be instaaled. Where in the cooling cycle the pressure is measured should matter.

[transomstand]

Where on the exhaust plate? Are you right tap directly into the water pump discharge plenum? That might have something to do with it. Do you have the hose from the top of the block to the poppet cover? This water actuall bypasses most of the block (comes off the top of the supply plenum in the block and is directed to the back side of the poppet and out) and measuring pressure there may show less pressure and this is where the gage is suppose to be instaaled. Where in the cooling cycle the pressure is measured should matter.

I think he means the exhaust cover plate on the rear of the powerhead. That's the correct location for the water pressure fitting.

[njj502]

That's right Pete, and exactly where it is. Either way, I'm fighting two issues... no temp and high ass pressure.

[Go Time]

Thats right, I remember now the fitting on the top of the exhaust divider plate. So that ain't it. Do you have the hose from block top to poppet cover?

[3springers26]

My 98 pro max 225 has 2 hoses off the stats running to the bottom of the power head & the port side tees to the starboard then exits the cowl to the open hose No tell tail fitting..... have the 143 stats & water doesn't flow till the motor temp & stats open up. about 2-3 min. does yours flow water @ start up?? mine runs about 18 psi on the gauge @ wot 3 @ idle all with a new impeller.. my water system Is bone stk.. the poppet system is a fishing motor system On this engine... if you have another to try.. if the spring is incrrect it can't dump the water & will cause hi pres & over cooling.. if the rubber gromet in the block for the poppet is cocked... it will hang the poppet closed causing your Issue also,, I'm In Wi By Green bay & do have a complete bolt On mid with exhaust plate if you wanted to try it from a 225 super mag.. need your power head & gearcase.. Kurt