1993 88hp Evinrude J88MSLETE Cyclinder Heads HOTTT

[MrFishy]

Just purchased a 1993 88hp Evinrude seems to be running fine. Have taken it out twice with no issues. After having it on for 10 mins or so the cylinder heads seem to get very hot to the point that I can't touch them without burning my fingers. The water coming out of the tail seems to be warm but not hot. I rode around for an hour or so with no issues yesterday. Pushed it half way on the throttle and went 43mph Is this normal for the heads to be so hot!? Im planning on switching out the water pump, changing the lower unit oil (any idea how many quarts it takes?), and painting the motor.

Any other recommendations?

Thank you in advance,
P

 

[TrueNorthist]

An infrared temp gauge pays for itself in minutes. $20 at your local discount auto parts store. Just point at various spots on the engine and write down the numbers. Unless and until you know the actual temps it's meaningless to comment further.

 

[jakedaawg]

Yes, do the impeller but while your at it get some temp sticks or an infared gun and see what you are running. It.may be due dor the stats and poppets. Not fun on a bubble back

 

[emdsapmgr]

Your engine will vary it's head temps depending on whether the bypass is activated in the thermostat housing or not. 1. At idle: all cooling water flows through the two thermostats on it's way out of the block. This is normal. Idle head temps should vary between 143 and about 155. 2. When the boat is planning. Once the boat is up on plane, the onrush of water (caused by the speed of the boat) will force extra water into the engine's powerhead. This extra pressure will cause both of the pressure relief valves to open (one for each head) and flood the engine with tons of extra cooling water. When this happens, you will see the cyl head temps go down maybe 20 degrees or more. Maybe in the 120-130 range. That's normal-extra cooling for WOT operation. So, you need to monitor the powerhead temps with a laser temp gun to see if your cooling system is functioning normally at both idle and when on plane.

 

[TrueNorthist]

I plan to install a gauge cluster which really ought to be standard equipment with any engine. Over the years I have had a lot of fun taking engine temps with a hand-held infrared, while alone in the boat. Same with rpm readings using a Vibratach but I digress. Further to emdsapmgr's (and other's) astute remarks above, my engine had frozen relief valves and would get very warm when at speed, but never quite enough to trip the horn or do much damage and also not quite enough for alarms to go off in my head. However an old engine + high heat = new anchor, so I replaced the relief valves and springs anyway and as an added bonus was able to remove several pounds of salt crystals and deposits which puts my mind at rest. However a few gauges -- hand-held or otherwise -- will serve you most well and pay for themselves twice over every extra minute you have on the water.

Best of luck

 

[MrFishy]

Ordered an handheld infrared from ebay for 12 bucks. Going to change the lower unit oil today and waiting for the water pump kit to arrive. Thank you all for the info. I appreciate it : ) will post pictures of the engine one I get the temps.