150 hp Blackmax overheating

[arjo]

Got a problem with my 1986 V6 150 hp,the overheat alarm sounds immediately when engine passes 3000 rpm.
Back to idle, alarm turns off almost at once.
Strong and good tell tale but a bit hot I guess,impeller 4 months old.
Suspect poppet valve, I have the "old " design with the small cover.

Anyone that can tell the part nr on the poppet valve kit I need?

When I bought the engine I noticed that the tell tale pressure vary from strong to less strong when Idling, depending on therm`s opening or closeing I guess.
Now the tell tale is very strong all the time at idling.

As long as I have had the engine there has never come any water out with the exhaus from the two holes above the water.

Should it?


Need some advice here!

[arjo]

Went to my boat,let it ran some minutes at idle,seems like the head at port side is a good bit warmer then the starboard side. Normal?

Have just taken the poppet and stats out, poppet and its parts look very clean and good , some salt and dirt at the stats, tested them in a
can with boiling water, the one at port side seems going a bit slow,cleaned it and moves much better.

Will run for a ride later today after reassemble the parts, will let you know what happens.

[arjo]

Good news!
Mounted all toghether. Ran it at idle about ten minutes,now the tempature is the same at both heads.
Left harbour and ran at from 3000 rpm to wot for a while,no alarm,both heads still same tempature,warm but no problem keepin my hands on them.

Lets hope it stays that way.