Does this tell me that my head is cracked and at those RPM's the pressure from the crankcase is pushing through somehow to the head and blowing the freeze plugs????

Have you run this hot that you can remember, ie. overheating

Your on the right track but hopefully it's just a popped head gasket. Get a leak down gauge (not compression tester) and perform a leak down test. If you're not familiar how to perform a leak down check, I can post up with instructions or I'm sure you can search it.

(IMO) Could be:
Bad head gasket
Cracked Head
Warped Head
Cracked Block
Warped deck surface (on block)

There are other spots that could leak and cause coolant in the oil, but no others that I can think of that would cause the cooling system to over pressurize enough to pop the plugs out.

Another route you can go is pressure testing the cooling

 

Thanks Wilson! Those were some of my next steps planned - initially compression test though... guess I'll start with the leak down... I've never performed one of those before, unfortunately. If you have the info, I'd gladly welcome it!

As for the temp, if I recall, 160-185ish has been pretty normal operating temp. I've been riding it at race conditions most frequently, so I don't recall what was normal temp at regular street riding. That still seems about right though... It has never overheated however.

I just find it very strange that for the second time in a row now, once i rev it up to 10+K RPM, it almost instantly pops a freeze plug... It's the strangest thing ever!

ALSO..... I have a back up bike - 96 GSXR 600 that I tore down just to check the freeze plugs.... and guess what... they were out too! Dang it! So much for using that one as a spare... maybe I'll get lucky and find it to be just a bad head gasket... would freezing really cause that though and that much added pressure to push out a freeze plug??? Thanks again!

 

My computer keeps locking up. I meant to give you more info on the first post but my computer froze. A leak down basically shows you where you lose combustion pressure (or if you lose it) Most times mechanics will do a leak down test after something fails a compression test because it will show you what is failing in the engine. i.e. rings,valves,head gasket In short, you pressurize the combustion chamber (TDC compression stroke so both valves are closed) with around 100psi air pressure and it should hold the pressure steady. If it doesn't, you find out where the leaking air is coming from.

Coming out carbs- Intake valve problem (bent valve, bad seats etc)
Coming out exhaust- Ex. valve problem
Bubbles in coolant(radiator)- head gasket,cracked/warped head block
coming out of Oil fill cap or crankcase vent- broke/worn rings

Basically, (in your case) it will just confirm that you have a combustion leak into your cooling system but you'll have to tear it down to find out exactly what it is.

Since you're really not trying to investigate your engine condition, you could probably get away with just putting 100psi or so of compressed air into each cylinder at TDC on compression stroke and looking into your radiator. That way you won't have to buy the gauges- you'll just have to fab up an adapter to connect the air hose to the spark plug hole. (compression tester hoses work great)

Water freezing in the block WILL DEFINITELY cause the plugs to pop out. It's not so much "pressure" it causes, it's the expansion of water when it freezes forcing the plugs to pop out. I've seen a couple V-8 blocks crack because water froze in the block but the plugs didn't pop. Freeze plugs are actually nothing more than caps(plugs) that plug the holes from where the sand is used in the casting process of the block, it just so happens that they usually pop out first when water freezes in the block because they are the weakest link.

The fact that they pop so quickly at higher RPM (higher combustion pressures) almost guarantees you have a combustion leak.

Try out the air pressure test, that way you know what cylinder(s) is causing the problem so you know where to start when you tear it down.

 

Did you re-install the old plugs or new freeze plugs? What sealer did you use?

Most importantly, Did you bleed ALL the air from the cooling system and check to see that your overflow line isn't plugged. Air in the cooling system that gets trapped on the bottom end has been known to pop a few freeze plugs in my time epically on aluminum engines. I am thinking with the High revs you mentioned at 12k and the fact that is when you seen the oil in the water I would venture to bet on the Air in the system is the culprit. Not that a leak down test wouldn't hurt and you'd learn something new, which I am a fan of, but I don't believe the head gasket is suspect because, you mentioned no probs at 8k, the oil pump is producing way more pressure than the water pup at the mark, and would easily push oil into the crankcase. But that is just my thoughts.

I would put new freeze plugs in, brass ones, sealer or not doesn't really matter they are designed for an interference fit( the plug is slightly larger than the hole) , I use sealer, just in case the plug was made in china and the plug isn't really round. I use an impact socket to tap or sometimes beat them into place, right after an hour in the freezer to shrink them a bit. LET THEM THAW PRIOR to starting the bike. Then fill and bleed the cooling system, I like to run the engine with the radiator cap off let it warm up, adding water on the way, it will eventually start puking some water out, after the thermostat opens and the bike is warm, I usually stop and start the engine several times aswell with the cap off, try keeping the revs low for a bit, monitor the temp as erratic reading is sure sign of air-lock in the cooling system.

If you still have problems with the plugs popping out, Locktite make some sealer to keep bearings in place on a shaft I'd give that a try!

Lets us know how it turns out.
cheers:cheers

 

I am thinking with the High revs you mentioned at 12k and the fact that is when you seen the oil in the water I would venture to bet on the Air in the system is the culprit. Not that a leak down test wouldn't hurt and you'd learn something new, which I am a fan of, but I don't believe the head gasket is suspect because, you mentioned no probs at 8k, the oil pump is producing way more pressure than the water pup at the mark, and would easily push oil into the crankcase. But that is just my thoughts.

How would air in the cooling system cause it to build enough pressure to pop a freeze plug? Doesn't air in the system cause it to NOT build pressure as the water pump is not moving the coolant at a high flow rate (or at all) It'll cause overheating but I've never heard of building excessive pressure because of air in the system?

He sees the water in the oil, not the oil in the water. Was that a typo or were you thinking something else?

What does the oil pump have to do with combustion gas leaking into the cooling system?

I'm just curious as none of this makes sense to me?? I'm always willing to learn something.

 

Thanks again, Wilson! I'll give it a shot and see what I come up with!

 

The only thing I should have added was check that your thermostat is opening.
Oh and I f I remember correctly use locktite sleeve retainer, green stuff, it will keep those plugs in place.

 

The freeze plugs your using may be a little undersize ??
alternately you could tap to suit a tapered pipe thread and screw in a blanking plug

 

Thank you everyone for your feedback! The plugs are the originals that came out. They all appear to be in perfect condition, so I reused them. So here is my plan of attack... Do all of the compression testing and leak down tests, if all is well (fingers crossed) I'll try either finding some new freeze plugs at the autoparts store and/or try the existing ones with some different sealant. The stuff I used before was the red gasket sealant stuff for high temp applications... Is that not the correct stuff? I'll let everyone know what I find when I pull it all back apart... maybe this weekend or Friday.

Thanks again guys!!!!

 

if they are the original ones then they are crushed from being in the block. . maybe get new ones and loctite them in. they are actually bigger than the holes in the block new. then when you press them in the hold. . after being in the block for years they will not have the same hold.