Crystals around head gasket?

[Hotrods]

For the past 2 times I’ve taken the boat out I have noticed a crystal like substance near each edge of my head gaskets. {like ice crystals) it is a white substance that almost looks like its coming out of the heads between each side of the gasket. It is seen on the top and down the left side you can wipe it up with your finger and it's just a chalky kind a stuff.<br /> <br />12 hours on rebuild, heads were re- torqued. <br />Motor still running a little sloppy at low RPM's.<br />Could both my head gaskets be leaking,, it almost looks like salt crystals..but no taste<br />Yea it was salt water i was running in.

 

[Dhadley]

Re: Crystals around head gasket?

Some head gaskets will do that. I've been told by an engineer that its a silicone type substance thats in the head gasket material. Comes out with heat. ???? At any rate if its not salt its nothing to worry about. I know -- its apperance bothers me too.<br /><br />Whats wrong with the idle?

 

[Hotrods]

Re: Crystals around head gasket?

Dang.. thought I found the reason she's runs sloppy at low idle.<br /><br />Dhad?.. Since I have you here..lol<br /><br /> if i feel water going into my heads thru the hoses right at start up. would this mean my stats are stuck open? plus i only see water coming out of the starboard side exhaust releaf hole<br /><br />And what should my idle be on the muffs since it gets lower in the water.. when I start her on the water she starts right up with a little throttle but then when i bring it back to put her in gear i need to do it fast for fear of her stalling.

 

[Dhadley]

Re: Crystals around head gasket?

The amount of rpm loss when in the water vs on muffs depends a lot on how low the motor sits when the boat is in the water. Obviously a motor on a small narrow boat will sit lower than the same motor on a wider longer boat. <br /><br />Another factor is how good the piston skirt to wall clearance is and the condition of the rings. Since its a fresh rebuild all that should be good.<br /><br />The idle needs to be set in the water as the boat normally sits to get the normal backpressure. It needs to be somewhere around 650 in gear. On older carbs sometimes we have to rejet the idle circuits.

 

[Hotrods]

Re: Crystals around head gasket?

I will check it in the water next time, thanks.<br /><br />Are my stats stuck open? I shouldn't feel water in the head lines when I first start her.. should I?

 

[Solittle]

Re: Crystals around head gasket?

hotrod - No cause for concern on the crystal substance. Both of mine have it.<br /><br />I suspect that you need new t-stats. Many guys run without them but OMC motors do not like to idle well unless at normal operating temp. That may be part of the reason your idling is a bit finicky.