Heating at hi speed and under load .

[tigerhack]

Mercrusier heating at hi speed , risers are not blocked ,impeller is new ,water pressure is good ,hose not crink ,hose not sucking air ,water pump good,thermostat is removed,no hose is clogged, boat idle at 100 F but temperature rise rapid at hi rpm under load 5000wot .what is my problem ? 1992 regal chevy 350 engine 5.0 liter.

 

[bomar76]

Re: Heating at hi speed and under load .

Retarded timing will cause an engine to overheat like mad.
If that isn't it, you are wrong about everything else being OK.

 

[bigbrownbuku]

Re: Heating at hi speed and under load .

WHAT? the last part of your post makes no sense. is your water pump good? thats where you should start. my best guess is the base gasket under the water pump wasnt replaced, its classic for a boat to stay cool at idle but overheat once on the step because the water level drops below the water pump base and the pump sucks air instead. put your thermostat back and troubleshoot the problem with the thermostat installed.

 

[tigerhack]

Re: Heating at hi speed and under load .

WHAT? the last part of your post makes no sense. is your water pump good? thats where you should start. my best guess is the base gasket under the water pump wasnt replaced, its classic for a boat to stay cool at idle but overheat once on the step because the water level drops below the water pump base and the pump sucks air instead. put your thermostat back and troubleshoot the problem with the thermostat installed.

yes that was already replace .

 

[bhammer]

Re: Heating at hi speed and under load .

Why did you remove and not reinstall the thermostat? If for troubleshooting, you need to reinstall it and see if the same conditiond exists. Removing a therm will / can cause the engine to get hot. The experts can explain it better than me.

 

[tigerhack]

Re: Heating at hi speed and under load .

Retarded timing will cause an engine to overheat like mad.
If that isn't it, you are wrong about everything else being OK.

I want to check the timing without any overly technical approach ,well the engine idles good ,Wot at 5000 rpm i do notice several time if i should bring the throttle to the max fast(sudden) the engine would stall (shut off) could that be the timing ? facing the engine whitch is the advance or retard position ?

 

[tommays]

Re: Heating at hi speed and under load .

Tiger

Do you still have all those auto mix and match parts on there how about a recent picture

 

[Bondo]

Re: Heating at hi speed and under load .

Tiger

Do you still have all those auto mix and match parts on there how about a recent picture

Ayuh,............. What da ya wanta Bet Tom,..??..??..

thermostat is removed,

So,.... Put the Right 1 Back In.........

 

[bomar76]

Re: Heating at hi speed and under load .

I want to check the timing without any overly technical approach ,well the engine idles good ,Wot at 5000 rpm i do notice several time if i should bring the throttle to the max fast(sudden) the engine would stall (shut off) could that be the timing ? facing the engine whitch is the advance or retard position ?

There is ONLY one approach to timing:
Buy a timing light.
Set the timing using whatever procedure is appropriate for you ignition system...
and I have no clue what you have.....after the others mentioned it, I do kinda recall you having some sort of time bomb though.