Overheating - hooked up water pressure gauge, What should I look for ? '87 Ev 90HP

[bang4dabuck]

I also tried a clear tubing in place and observed running cool and then hot. I also saw water stop coming out all together. I shut her down then. this was after about running 2 minutes in a container of water. Does this mean anything ? Air in the system, new water pump not in correctly ? I might have blocked small gap in impeller housing where it seats. I will play with it again with pressure gauge hooked up replaqcing clear tubing.

 

[bang4dabuck]

Re: Overheating - hooked up water pressure gauge, What should I look for ? '87 Ev 90H

Got inpatient and started her when starboard head was around 130. PSI stayed about 15 but had to cut off after 2 minutes. Got too hot !!!

 

[emdsapmgr]

Re: Overheating - hooked up water pressure gauge, What should I look for ? '87 Ev 90H

That engine will pump 6-8 lbs of water pressure at idle. Maybe 17-19 at full throttle. The engine should idle between 145-150. Maybe as much as 155 at idle in the middle of the summer. When you are on plane, the cyl head temps will go down, depending on how cool the lake water is. The control box will signal an overheat when the cyl head temps get to 212 degrees, and will quit when the cyl head temps get back down to 175. Even 175 is too hot for normal operation. Keep in mind, if either of the two thermostats sticks shut (one for each head) , it will block water flow to that head and cause an overheat.