Thought I had water in gas, nope, thought I had head gasket leak, nope

Thought I had water in gas, nope, thought I had head gasket leak, nope

2010 Husky TE 450 will start and run great, shut it off, won't start in as little as 5-10 minutes or later that night or the next day. Crank it til the battery flats, pull the plug, looks like water to me. Drained the tank a couple of times, got gas from 3 different stations, also switched to regular, still same problem. Decided I had a blown head gasket, got some BlockChek and that test shows no exhaust gasses in my radiator. If I ride it til its hot and shut it off, and remove the rad cap (taking the pressure off the coolant system), it'll start after 5, 10, 20, 30 minutes, an hour and overnight.

Is it possible to have such a tiny head gasket leak that water can be pushed into the combustion chamber when the engine is not running, thus killing the spark on next start up, but once the bike is started, it runs great? There are no bubbles in the rad fluid stream and no coolant in the oil.

Well you know how the coolant pressure can build after shutting off a hot motor, as the heat in the head raises the temp of the now non-moving coolant. Usually there are signs of combustion in the coolant,with a cracked head or blown gasket because the compression pressure is always higher. Hmmmm Did you taste what you suspect is coolant?

What does your oil look like? Is your coolent level going down (loosing coolent)?
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IMHO sounds a bit more like a cracked head than a gasket issue (please don't shoot the messenger). I hope that's not the case. Cracks can seal up under normal operating temps and open when cooled off allowing the cooling system pressure to push the coolant into the cylinder. When you looked for bubbles were you rapidly revving the engine? You can run a hose from the overflow tube into a jar of water and rev the engine. If combustion pressure is leaking into the cooling system it will produce bubbles. Hope you get it sorted out without a big Husky parts bill...

If it was a car I would be so much of a help, but as it is sounds like a heat soak issue- do you have spark when this happens? If so and I know you are one of the guys who found reasonable priced fuel pumps for FI bikes- do you have fuel pressure? Maybe spray a little fuel down T-Body 2 see if you get a response-auto fuel pumps will make noise like they are working but they are not pumping, maybe someday they will be obd2 compliant where we can see a data stream - second thought do FI bikes have a test port to check fuel PSI? 3rd thought If bike responds to forced fuel U either have a fuel pump issue,a injector pulse issue,or an injector issue.

IMHO sounds a bit more like a cracked head than a gasket issue (please don't shoot the messenger). I hope that's not the case. Cracks can seal up under normal operating temps and open when cooled off allowing the cooling system pressure to push the coolant into the cylinder. When you looked for bubbles were you rapidly revving the engine? You can run a hose from the overflow tube into a jar of water and rev the engine. If combustion pressure is leaking into the cooling system it will produce bubbles. Hope you get it sorted out without a big Husky parts bill..
.IN my auto expierence metal expands when hot allowing cracks 2 open then leaking in cylinder creating misfire most common at idle then clearing up-3.7 and early 5.2 and 5.9 chrysler engines,the 5.2 and 5.9 like to do it at highway speeds also low rpm.

Oil is fine, no coolant in the oil.

Yes, high idle, not so high as to blow coolant everywhere, but there are no bubbles in the stream. I also put a rubber glove over the rad opening, sealed it, and waited for the glove to blow up with pressure, it didn't.

When I pull the plug and it seems to be wet with water, the spark is yellow and weak looking. All I have to do to get it running again is to pull the plug, wash it with alcohol, put the plug back in and it starts and runs great. It's just not a fuel delivery problem.

Maybe you thought I was kidding when I asked if you tasted the liquid on your plug. Actually, I wasn't.
You will know if it is coolant or not, unless you are using water for coolant and if you are, add some anti-freeze, your taste buds will pick up the sweet taste.

I should have, but I didn't, taste the stuff on the plug above. I know it didn't smell like gas, it smelled like nothing really.

If it is still a mystery where the liquid is coming from and if it was me... I would do it over, get it running, warmed and up to temp, shut it off long enough until you know (think) the plug will be wet again, pull the plug and taste the liquid drop on the plug. Then you will know for sure.

I don't think it's a mystery where it's coming from, pretty sure it's coolant, plus it's gonna taste less like coolant, I am running 75% water now.

And just this morning, I go out to the garage, rad cap is off, been off all night, bike fires right up.

The mystery for me now is, what exactly is happening if I get it hot, shut it off for 10 minutes, and then it won't start, but if I pull the plug, squirt some alcohol on the plug and put it back in, it'll start right up.

Sorry OHR. Hope she's not too busted up.

No need for sorry Aaron, the bike is running great, it just won't start after sitting hot for 10 minutes and greater. Heck, took a newbie out to the dried up lake, 60 mile round trip, dual sport, got 27.5 MPG, my worst ever, I took my radiator flaps off thinking I was leaving them closed too much and running too hot. Also, I let the bike run at all our stops, when we had to stop to fix a guy's flat, I loosened the rad cap, and the bike started great after a 30 minute break.

Thanks Rajo, this is the kind of thinking I was not doing and was looking for the different thinking from standard stuff, your theory has some good aspects to it, like "no cylinder pressure, thus no bubbles in the coolant stream". I think that this might be close to what is happening.

Also, since I am having no major loss of coolant, I don't know that I have anything to fix until I can put my finger on the exact cause.

I think Rajobiguy is on to something. You could warm the bike up, then shut it off with the rad cap on, wait 5 min. Don't try to start the bike, just pull the plug and see if it's wet. (combustion chamber leak) If it's not wet, and you have the time and tools, you could warm up the bike, leave the rad cap on, move the throttle body out of the way and inspect the intake port for coolant. Hope this helps.
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Sure seems like the right track

That's definitely some good additional thinking on that subject to pinpoint if the source is the intake area.

Here's a post from ADV, I may be using some sealant soon...

Originally Posted by D_A
It is very possible, and I've seen it more than once, for the head gasket to have a small leak that passes coolant one way but not combustion gasses the other. It happens when the gasket de-laminates and forms a little flap that opens when the pressure is coming from the cooling jacket side but closes and seals when the pressure comes from the cylinder side. Usually the engine won't use tons of coolant or show combustion gasses in the coolant but it always gets worse eventually as the leak gradually erodes metal from either the head or cylinder.