Temp? 140 4 Stroke

[bustab]

Hi, I'm working on a 140 4Stroke Model J140PL4ST.

It has an overheat problem...I checked the water pump it is good and changed the thermostat.

i have a infrared temperature gun and noticed the bottom half of the cylinder head is running about 87 degrees at idle and the top half is about 150 at idle. with a steady climb in temp as rpm increases.

i'm running it on a hose with no load.

could it be a blockage in the water passage somewhere?

what is normal operating temp for this engine?

any help would be appreciated...I'm new to Johnson/Evinrude

Thanks,

 

[CharlieB]

Re: Temp? 140 4 Stroke

Checked the water pump?

If you were there you should have gone ahead and changed the impeller, at least if it is over a year old. New gasket/seal.

You need to pull the heads and replace the water diverters to redirect the water flow path around the upper cylinder.

 

[bustab]

Re: Temp? 140 4 Stroke

ok i changed the waterpump. what is involved with changing these water diverters? pull the power head? is there any kind of poppit type valves on these motors thsat could be the problem?
thanks

 

[bustab]

Re: Temp? 140 4 Stroke

i pulled the cylinder head and found some rust on the inside of number 2 cylinder....it looks to me like the head gasket is leaking a bit. there is also some rust on the head coming from a water passage beside number 1 cylinder that goes down to the number 2 cylinder...

shouldn't this have showed up on the compression test? i wish i would have done a leak down test before ripping it apart but i'm going to try a new head gasket even though this one looks ok.

anyone have any tips on getting the valve train back together? because all the valves are closed now with the cams off. so should i just bolt the cams up and line the marks up with TDC #1 compression.

thanks,

 

[clanton]

Re: Temp? 140 4 Stroke

The head may have a crack, should be checked.

 

[CharlieB]

Re: Temp? 140 4 Stroke

When all else fails..........


READ THE DIRECTIONS.


A Factory manual is THE most valuable tool you will buy for your motor.

After-market are cheap imitations, lacking the specifics that prove invaluable.


I just re-read your post and realized you have a 4 stroke. Without the manual I can NOT tell you the specifics with seeing and looking, one of the other more qualified adviser can better assist you.

Get the book, it will prove to be the most valuabale assistant you can have.