Mercury 220 laser efi motor loads up while idleing and overheating at cruise

[Zonafried]

Serial OB143905
1987 Champion 201i think

40 original hours
4 blade prop
Manual being ordered from European asap
Please forgive me Im new to this forum and ive never owned an outboard motor
Found this time capsule on craiglist a few weeks ago and after some searching for a missing fuel tank replaceing the impeller and fuel filter a little cleanup we were able to get it running fairly well a couple of issues came up once we got it on the lake...yes it floats!
Water pressure gauge not working although tell tale pees pretty good the guage didnt increase off idle as it should and we had an alarm long beep (service guy said Temp but no codes on this ecm to read)
I took the t stats out and tested them prior to running the motor they worked fine
Is there a poppet or other things i can check
And as far as the idle loading up Other posts mention primary pump diaphragms allowing fuel to leak into block would that also maybe why we used a LOT of fuel and what other things can i check it looks like a fuel test shrader below the pump and vst on another metal block behind the ecm
She runs right up to 60 and sounds great aside from these issues.

[EuropeanAM]

Have you replaced the Water Pump? That DEFINITELY should be done.

Good possibility that the injectors in that engine are WAY on the rich side... they usually started their life that way, and got worse with time.

Good idea to check all of the basics, and then see where things need to go from there.

Compression (AND LEAKDOWN) Tests
Spark Test
Fuel Quality, Delivery, and Pressure Test.

[Zonafried]

Thanks for your input European we found the impeller in bits and pieces that has been replaced is there a water pump and is it recommended to replace the injectors rather than sending these out for cleaning and testing?

[EuropeanAM]

Price them... that should answer the question for you.