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Coolant leaking into engine?

277 Views 11 Replies 5 Participants Last post by  Waahson
Got my electrical problem sorted out, then the bike started spewing white smoke out of the right exhaust (which was also running hotter) and running very rich. No coolant leaking out of either of the side holes. We took out the air filter and played with the idle and pilot adjustments, but got nothing to go off of.

Went to perform a valve adjustment while I wait for a compression test and some o-rings to show up and there was some nasty gunk on one of the coolant pipes. I won't lie, I forgot if it was the left or the right one. Pretty sure it was the left one, because I think I remember being confused thinking the right one should be dirty if anything. Not sure if this is a bad sign or if it's just debris from the bike being stored outside. There are some spots on the valve cover that mice and chipmunks like to nest on, but this gunk was oily, which I figure I shouldn't find on a coolant tube. It was also above the o-ring, so I'm not sure if that means anything.

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Anyway, the o-rings on the pipes look good under all the gunk, so I don't think they need replacing; but I do have replacements on the way. The spark plugs were put in after we noticed the white smoke coming from the exhaust, so they have 0 miles on them and have only been run for no more than 30 minutes. The right plug still looks brand new. The left plug is already burning though. My grandfather and I are confused since, again, we figured it would be the other way around if anything.

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Compression kit should be here Wednesday/Thursday, so I have that on my to-do list. Are there any other tests I should do/can do while I wait? I'd love to diagnose this as something other than a blown/cracked head gasket, but my old man is fairly convinced that I somehow blew a gasket. Not sure if miles matter, but the bike only has 8.8k miles on it, just figured a head gasket failure would come from more use; but I guess age storage are also factors.
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couple of thoughts for what it's worth. coolant tubes. those O rings are to keep the coolant inside the system so muck on the tube above the O ring is to be expected. for two reasons some like to add lubricant to the tubes to aid assembly so it would eventually wash off below the O ring but not above it then any muck drops in that area it sticks to the lubricant, also one expects there to crap between the tube and head as there is gap for it to fall into.
this is normal sometimes there can be that much of it the tubes get welded in place.
it's not that uncommon that the tubes are damaged trying to remove them.

spark plugs. one of the diagnostic tools we use is the plugs. whenever you take them out they should be both exactly the same. this shows the engine is running well and in balance if one is brown and the other black the black one is running rich or burning oil. but if one is brown but the other is grey or white the lighter one is running weak.
they both should be a brownish orange colour.
looking at yours it's obvious the cylinders are not working in unison. either one is running hot or burning something while the other is not or the coloured one is working correctly and new looking one is under working.
without knowing the bike which scenario is correct would be just a guess but for sure the bikes not running even as it is.
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Alright, so the pipes are good then.

We figured it wasn't running evenly, just aren't sure why. My grandad seems to think both plugs should be pretty white instead of a little brown with how new they are, but he's been wrong a couple times before. Was really just hoping for some more troubleshooting suggestions before I'm able to do the compression test, but I get not really knowing what to suggest without being able to poke and prod at the engine yourself.

I just want to narrow it down to the head gasket before I commit to doing a replacement. I'd absolutely love to not have to replace it. Everything so far has looked good, other than the plugs. Hell, I'd even go as far as to say everything we've looked at so far has been in fantastic condition, all things considered.

Sorry if I'm coming across annoying, I'm learning a lot these days and I'm doing my best to keep up haha.
Water (white smoke) has only one route to he combustion chamber 99% through a head gasket
1 cracked cylinder wall
1% cracked combustion chamber in head
allmthe stuff you have done so far is useless.

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Guess I'm ordering a new gasket then. Already got one of your old posts from '09 bookmarked in prep for the head removal.

Coolant pipes from head
Valve cover.
Cam chain tensioner
Undo the 8 bolts
Head come off.

Seems straightforward enough.
Guess I'm ordering a new gasket then. Already got one of your old posts from '09 bookmarked in prep for the head removal.

Seems straightforward enough.
White smoke does not by itself indicate a cylinder head problem. In fact given the history of these engines I would be amazed if you had such a problem. White smoke (did you smell it?) could be a carb side problem, hence the rich running. Also, if the white smoke where coolant then you would see a corresponding drop in the header tank surely, along with an excessively pressurised system (like steam venting from the header or radiator cap when you remove it slowly!) Leaving the engine running even for less than 5 mins will indicate what is wrong. Also, the thermostat may be faulty.

Replacing the cylinder head gasket is fraught with horrors on these engines, for the basic home mechanic. So I would double check all the above first before plunging into the deep end with this problem :)
Well I just performed a valve adjustment (only one really needed an adjustment, but I did them all), so I might as well do the carbs while they're easy to get at.

When we looked up white smoke (both for this bike and in general), literally every single result said it's a head gasket, so that's why we went down this road. But, like I said before, I'd love to be wrong and not need to replace it. Especially after reading all this stuff about lapping...? Yeah, out of our wheelhouse with that lol.

Will definitely look into everything you mentioned. Thank you.
I've heard a white spark plug can be a symptom of a little coolant in the combustion chamber. I don't think it's the only reason but adding your symptoms together, it looks more likely
A compression test will pretty much confirm whether it's the head gasket or not, correct?
It might but I'd expect it'd be pretty bad-the escaped air from pumping the engine would want to bubble up the radiator hose but wth the thermostat closed, it might not easily do that....however, if you DID see bubbles lookiing in the open radiator cap, well that'd be bad news confirmed...

Any steamy goo on the valve cover when you looked at valves?
Wish I knew to look for bubbles or steam coming out of the radiator before draining it, I can't say for sure if I remember.

No goo or anything abnormal on the valve cover or the valves.

I do need to properly torque the nuts on the valves before I start the bike (we couldn't find the adapter we needed..)

I suppose the current plan is to check the thermostat/wiring, torque valve nuts, put coolant back in, run a compression test, then run the bike for a few minutes and check the radiator cap for smoke/bubbles. Compression kit arrives tomorrow and hopefully we can find the right adapter for the torque wrench so I'll report back soon.
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