2015 ETEC G1 250 HO Overheat - both heads and computer getting hot

[barronj]

I have this motor on a tunnel style hull (cat hull). It's a short shaft with the large pick-up scoops. Shallow running with the jack plate way up is common for the region I fish, and on these hulls, it's been found that a lighter spring in the blow off valve helps keep the motor cool when jacked up and moving at speed, so I had those installed a few years back to fix the overheat I was experiencing when running the motor jacked way up. Ran fine for 2 years after that. NOW it's getting hot at WOT with the jack plate all the way down, the mechanic says my water pressure is not the problem, says it's high even, but that there's not a dumping problem. Thinks there's a blocked passage somewhere in the middle of the block?

Motor is always flushed with fresh water after use (saltwater environment). Water impeller is new.

Model # E250HGLAB
Serial # 05435994

Anyone who's experienced similar and fix, your input is appreciated.

[SEAHORSE]

What overheat service code is displayed using the diagnostic software?

What is the water pressure reading and rpm at the speed the motor overheats?

Has your tech tested for aerated water flow using clear tubing at the affected speed?

[barronj]

I’ll get the code on Monday morning.
The pressure that I normally see on the gauge is around 20 but he said it was as high as 35, I don’t know I’ve never seen the needle climb that high. 5200 RPM?

[barronj]

code 69 @ 290.5 hrs starboard side 9 times
code 43 @ 282.5 hrs port side 5 times
code 25 @ 281 hrs 1 time

[SEAHORSE]

code 69 @ 290.5 hrs starboard side 9 times
code 43 @ 282.5 hrs port side 5 times
code 25 @ 281 hrs 1 time

yessir, within about a 9 hour time frame, all three items overheated which usually means a restriction such as mud, sand, weeds, etc somewhere inside or outside the motor, aerated water which does not cool properly, or lack of adequate flow from the pump, passageways, or components such as pressure relief valve. Often debris restrictions are temporary but in your case a complete inspection starting with the pump assembly should be the first thing to do if a visual inspection of the boat and the motor do not show anything obvious.

[barronj]

They asked if i wanted an acid wash. They said that if it were red bloom (algae) that an acid wash would flush it and fix it, but they also said that they hadn't done that anytime recently and when one boat needs it, others will have needed it or will need it, so not super hopeful. They're talking about the mid section now, an exhaust housing. If I do that, I'll be $3000 in, since I'm already at $500 in for their work so far.

[SEAHORSE]

They should map water pressure at 500 rpm intervals and at the same time inspect for aerated water flow through the EMM using a length of clear hose looking for bubbles.

[barronj]

What would it mean if it was not aerated until higher rpms?

[SEAHORSE]

Disturbed water flow coming off the hull due to improperly mounted thru-hull fittings, transducers, strakes or hull irregularities, even trim tabs too close to engine could be a problem

[JR19]

Disturbed water flow coming off the hull due to improperly mounted thru-hull fittings, transducers, strakes or hull irregularities, even trim tabs too close to engine could be a problem

I had this personally happen to me. It took me a while to figure out why I was get a overheat alarm when making a long sweeping turn. It was due to the side scan transducer I had recently mounted on my jack plate.

[barronj]

OK. I haven't changed anything though, not like you're describing. I appreciate all the feedback though!

Isn't there a European parts seller on this board that gives BBC discounts? I feel like I've ordered parts from them in the past but can't remember who it was.

[barronj]

Thanks for all the feedback SEAHORSE, turns out an acid flush cleared all the passages and it's running way cooler, even with the jack plate way up and running in the higher rpm range.

Mechanic says he normally only does those when we have a red algae bloom, he'll see a bunch of affected boats. Says he hasn't needed to do one in 4 years but it turned out to be the fix for me. I tend to run in super shallow waters of soft mud, I might come off plain in 1' of water and putt for a while, running some muddy water through my engine. I always flush (for an extended period) with fresh at the end of the day, but apparently I was getting build up as a result.