Mercury 650 Thunderbolt. Tell tale not working when engine?s hot?

[Timnaldo]

Greetings to all and this great site from Denmark.

We have a Merc 650 thunderbolt, and our problem seems to go as follows:
We start engine up, tell tale pours water just fine, we sail with full throttle at a about 5 mins with everything working fine, then engine cut out, now its difficult to start up again, and when it does it cant take the full throttle without cutting out. When the engine act like this Ive noticed that the tell tale are only dripping occasionally (Not pouring as earlier)
Any ideas?
Thanks in advance, and I hope you have the time to answer this.
Regards Tim

 

[Moody Blue]

Re: Mercury 650 Thunderbolt. Tell tale not working when engine?s hot?

Don't run the motor again until you replace the waterpump impeller. Hopefully it is not damaged too badly already.

Most likely, the engine is overheating (no water from telltale) and seizing up. That's why it quits and is hard to restart.

Recommended to replace the impeller every couple years. Cheap and relatively easy to do yourself if you are somewhat mechanically inclined.

 

[Timnaldo]

Re: Mercury 650 Thunderbolt. Tell tale not working when engine?s hot?

Hello Moody Blue.
The impeller has just been replaced (a month ago)
And it works fine to begin with, when engine gets hot, or another factor?, the tell tale are stopping to pour water.

 

[Timnaldo]

Re: Mercury 650 Thunderbolt. Tell tale not working when engine?s hot?

Now. As Laddies suggested it was dirt in the cooling system. Now it works fine. However, the engine still doesnt run well, but we have a feeling its the ignition system, maybe a bad ignition cable(if we are lucky
But!
Now it can run at atleast two cylinders, which is enough to get us around, and back home, hehe.
Still hope.