Twin 225 Pro Max water temp issue

**mragu** · 07-03-2022, 12:07 PM

At my wits end with this. Replace 200ff blocks with 225 Pro Max powerheads on 25” bass mids with standard gear cases. Powerheads had/have less than 3% leakdown and perfect compression when I bought them. Mechanic strongly suggested “free flow” cooling which I believe is no thermostats or poppets? Lowered motors down to lowest setting. Replaced water pumps. Had top two holes of gearcases closed. Port motor is fine and operates with correct pressure and temp. Starboard motor. On hose, turn up to 2000 then 3000 rpm, no issues. Put boat in water, heats up at canal speeds with hardly any “pissing. Horn go off and temp goes up. Limp in on one motor. Back at dock in water, 2000,3000 rpm pisses and temp is fine. I have a guy who wants boat but will not sell it to him this way until problem is solved. Anyone have any ideas or suggestions? Thank you in advancd

**David - WI** · 07-03-2022, 12:19 PM

Kind of a pain; but if you swap the lower units... you narrow it down to motor or lower?

**mragu** · 07-03-2022, 12:34 PM

Originally Posted by David - WI

Kind of a pain; but if you swap the lower units... you narrow it down to motor or lower?

Was thinking that. Going to putter around today. Too nice out.

**Jim Speros** · 07-03-2022, 01:52 PM

If you don't see anything unusual with gearcase , pumps tubes. While they are off rig a garden hose to water tube and flow hose pressure thru with engines off. See if both sides flow the same.

**mragu** · 07-03-2022, 02:36 PM

Originally Posted by Jim Speros

If you don't see anything unusual with gearcase , pumps tubes. While they are off rig a garden hose to water tube and flow hose pressure thru with engines off. See if both sides flow the same.

got it, thanks

**tlwjkw** · 07-03-2022, 02:46 PM

ya lost me at "free flow" ona bass (2 piece plates) mid??? never heard of such a thing?......

**scott reierson** · 07-03-2022, 03:03 PM

Maybe you picked up some stuff in the canal causing a internal restriction. Maybe those side screens in the water intakes are hiding something in there?
Sure hope is something simple for ya. The muck or sand might be packed up inside or jammed up stats. Hope not.

**mragu** · 07-03-2022, 07:23 PM

Originally Posted by tlwjkw

ya lost me at "free flow" ona bass (2 piece plates) mid??? never heard of such a thing?......

mechanic referred to free flow as removing t stats and poppets. Said what is done with 260’s etc. I believe he used the existing adaptor plates that were from the 200s.

**mragu** · 07-03-2022, 07:25 PM

Originally Posted by scott reierson

Maybe you picked up some stuff in the canal causing a internal restriction. Maybe those side screens in the water intakes are hiding something in there?
Sure hope is something simple for ya. The muck or sand might be packed up inside or jammed up stats. Hope not.

Hey Scott, hope all is well by you. Don’t think I picked up anything because it pumps water on land. Its when I shift it into gear. No screens on these lowers. He plugged the top two holes because he said I was sucking in air due to props raising stern of boat

**transomstand** · 07-03-2022, 10:44 PM

Hope you don't lose the powerheads Mike. If some total retard pulled the stats and poppets, you won't even be able to fill the blocks.

**tlwjkw** · 07-04-2022, 12:42 AM

Originally Posted by mragu

mechanic referred to free flow as removing t stats and poppets. Said what is done with 260’s etc. I believe he used the existing adaptor plates that were from the 200s.

ya might consider findin' 'nother guy.. thats tha dumbest thing ya can do for coolin' to a production 2 piece plate motor thats nowhere near tha same as tha 260/280 stuff.... jmo.

**H2OPERF** · 07-04-2022, 07:02 AM

Take a little tension out of the popet valve spring, I have seen that problem in the summer down here mostly on 25in motors. The problem is in the 1200 1500 range on long idle zones then they cool off as soon as the rpm/ pressure goes up and the popet opens allowing water to flow thru the block.

**transomstand** · 07-04-2022, 07:37 AM

Originally Posted by mragu

I believe he used the existing adaptor plates that were from the 200s.

This is really the key. Depending on if the powerheads are on 1 or 2 piece plates, the diagnostics and recommendations will be a good bit different for each. The 200 motors would have had 2 piece plates from the factory.