Loses power at 5000 rpms

[TnTommy]

2000 evinrude 50hp 4stroke after engine gets hot when I get up to 5000 rpms or higher about three min I lose power and rpms drop to around 2500 to 3000, I can run it at 4500rpms and it runs fine ,and when I throttle down to around 2500 to 3000rpms for a min I can throttle back up and is ok untill I hit 5000 rpms or more for more than a few min. Is it a fuel problem?
View attachment VID_20260617_142203294.mp4

 

[Crosbyman]

fuel burn is always hot it is not the cause. Lack of proper cooling water circulating inside the powerhead to draw out the heat allows it to build up so check impeller, thermostat, internal cooling channel obtruction (sediments).

POST your mdl#

 

[TnTommy]

E50PL4SS

 

[Crosbyman]

here is one answer from an AI source...
If your E50PL4SSC is a year 2000 Evinrude/Johnson 50 HP 4-stroke, and it overheats mainly at higher RPM, I would check these items in this order:

1. Water pump impeller and housing
   • Most common cause.
   • Even if the telltale stream looks good, the pump may not deliver enough volume under load.
2. Thermostat stuck partially closed
   • Very common on older engines.
   • Remove and test in hot water with a thermometer.
   • A thermostat that opens late can cause overheating at speed.
3. Blocked cooling passages
   • Sand, mud, corrosion, or mineral deposits in the cylinder head or water jacket.
   • More likely on a 26-year-old motor.
4. Pressure relief valve (if equipped)
   • If stuck, cooling flow at higher RPM can be restricted.
5. Weak telltale but normal at idle
   • Check for debris in the telltale hose and outlet.
   • A strong telltale does not always mean adequate block cooling.
6. Temperature switch or wiring fault
   • Verify actual engine temperature with an infrared thermometer before assuming a true overheat.

 

[saltchuckmatt]

Could be that SPECIAL sweet tea...none of that funny stuff in there I hope! Lol....

Get an IR gun and shoot the temp at where the head meets the block. Also shoot around the T-stat area.

Blockage, bad impeller, T-stat, and overheat sensor are all suspect.

Pretty sure that's made by Suzuki.

 

[Crosbyman]

SPECIAL sweet tea ??

 

[TnTommy]

It is made by Suzuki, the over heat alarm never went off, should it have?