GScott Posted July 9, 2012 Share Posted July 9, 2012 Out of the blue, when I started my '00 V11 Sport this morning it started running like crap. Missing and snorting. Died and didn't want to start. Since I was trying to meet up a ride I didn't get back to it until this evening. The bike will start and I can keep it running. But rough. Then I noticed the sound of an exhaust leak. I can feel the exhaust exiting the right head, just below the spark plug. I removed the plug and all appears normal in that regard. I'm assuming head gasket. What I've read about blown head gaskets result in oil leaks. I don't see any oil. Is a blown head gasket likely to cause an exhaust leak at 6:00 position? Or something else I should look for? Thanks. Link to comment Share on other sites More sharing options...
Admin Jaap Posted July 9, 2012 Share Posted July 9, 2012 If it is a head gasket, you should have much less compression in that cilinder. Any decent bikeshop can easily check that for you. Is the exhaust still tight on the cilinder? Maybe there is a small crack in the x-over? Also check if inlet is tight and sealed. You can easily be fooled by sounds. Let us know your findings. Link to comment Share on other sites More sharing options...
GScott Posted July 10, 2012 Author Share Posted July 10, 2012 Yes, the exhaust is tight. I have driven with loose exhaust header on a trip, and while annoying and loud it did not affect performance. I've had a chance to look at the exploded images of the head assembly, it looks to me like a blown head gasket and exhaust leak is a possibility at the #6 position below the spark plug. At least I don't see anything that would preclude an exhaust leak. I'll check compression when I get a chance, was just hoping for another likely explanation. Link to comment Share on other sites More sharing options...
gstallons Posted July 10, 2012 Share Posted July 10, 2012 This may sound hokey-pokey....hlod a lighted candle around the mating surfaces of the head/cylinder while the engine is running. You will find out VERY quick that it indeed is the head gasket leaking. Link to comment Share on other sites More sharing options...
luhbo Posted July 10, 2012 Share Posted July 10, 2012 ... was just hoping for another likely explanation. Any other explanation would certainly be worse. Really worse! hubert Link to comment Share on other sites More sharing options...
gstallons Posted July 10, 2012 Share Posted July 10, 2012 Oh yeah ! Link to comment Share on other sites More sharing options...
docc Posted July 10, 2012 Share Posted July 10, 2012 Yes, the exhaust is tight. I have driven with loose exhaust header on a trip, and while annoying and loud it did not affect performance. I've had a chance to look at the exploded images of the head assembly, it looks to me like a blown head gasket and exhaust leak is a possibility at the #6 position below the spark plug. At least I don't see anything that would preclude an exhaust leak. I'll check compression when I get a chance, was just hoping for another likely explanation. Most likely explanation is the loose intake boot. You can find it by inspection or spraying a solvent, like carb cleaner, around the joints and surfaces monitoring for a change in idle speed. Link to comment Share on other sites More sharing options...
mznyc Posted July 10, 2012 Share Posted July 10, 2012 Most likely explanation is the loose intake boot. You can find it by inspection or spraying a solvent, like carb cleaner, around the joints and surfaces monitoring for a change in idle speed. Carb cleaner eats rubber parts right quick Link to comment Share on other sites More sharing options...
GScott Posted July 11, 2012 Author Share Posted July 11, 2012 Well, mystery solved! And potentially a little embarassing since I should have noticed it straight away. Turns out it is not an exhaust leak at all, actually more of an intake leak! The throttle body and rubber hose had pulled off the intake port on the head. Somehow. I don't know how that would happen, the clamps seemed tight. It hasn't been dropped since I've had it, but I haven't had it long. But the whole T.B. contraption had slid back a bit further into the airbox. So on compression the air in the head was forced into the throttle body where it 'ricocheted' back toward the head. That's where I was feeling the 'exhaust leak'. So, false alarm. All is well. Thanks for your input. Now...back to your regularly scheduled program- Link to comment Share on other sites More sharing options...
docc Posted July 11, 2012 Share Posted July 11, 2012 Good to hear it's something simple. Check the whole tune-up/valve adjustment and throttle body balance to prevent a recurrence. Link to comment Share on other sites More sharing options...
docc Posted July 11, 2012 Share Posted July 11, 2012 Most likely explanation is the loose intake boot. You can find it by inspection or spraying a solvent, like carb cleaner, around the joints and surfaces monitoring for a change in idle speed. Carb cleaner eats rubber parts right quick So, what would you use? (I actually use electronics cleaner, since brake parts cleaner is probably even worse than carb cleaner.) WD40? Link to comment Share on other sites More sharing options...
mznyc Posted July 11, 2012 Share Posted July 11, 2012 I haven't needed to do the spray test ever.Just know that carb cleaner corrodes rubber and should NEVER go near the inlet boots. I had a similar thing happen to me as my boots came off their clamps.Im assuming a backfire created a vacuum which tried to suck the rubbers back in, Link to comment Share on other sites More sharing options...
gstallons Posted July 11, 2012 Share Posted July 11, 2012 GScott stated he felt exhaust or some kind of gases leaking beneath the spark plug area....how does anyone come to the conclusion it is the intake air boot ? Link to comment Share on other sites More sharing options...
Kiwi_Roy Posted July 11, 2012 Share Posted July 11, 2012 GScott stated he felt exhaust or some kind of gases leaking beneath the spark plug area....how does anyone come to the conclusion it is the intake air boot ? I don't know, but it seems Docc was right on the money if you read GScott's last post. Link to comment Share on other sites More sharing options...
luhbo Posted July 11, 2012 Share Posted July 11, 2012 .... So on compression the air in the head was forced into the throttle body where it 'ricocheted' back toward the head. .... I read this last posting and it looks as if there are no limits... Hubert Link to comment Share on other sites More sharing options...
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