Hi Everyone, I've been doing some work on my 959 to try resolve all the oil leaks. Whilst doing this I've noticed that the vertical head has tiny bubbles coming from between the head and head gasket. The image below shows where this is (to the right of the exhaust port when looking from the rear). The image below shows where these would be on the gasket. It doesn't seem to be leaking any fluid from here. The bike runs fine. No over heating. No mixing of fluids. 1. Is this early head gasket failure? 2. Has anyone seen this before? 3. Should I get it sorted now or leave it? (I'm probably kidding myself here) 4. Has anyone on here done a head gasket on a superquadro? If so, how bad a job is it?
That’s the base gasket isn’t it? Can’t quite make it out in the picture, my 899 does it after a ride. I’ve left it like that for 3+ years and it’s been fine.
I guess you could say it's the base gasket. The red line on the following image shows where the gasket is located. The arrow is the rough location of where I can see the bubbles. Is this the same location you're seeing them? How many miles have you done since you noticed it bubbling?
Yes thats where they are coming from on mine. Tiny bubbles almost like a slow fizzing and only when it’s hot? My bikes on about 37,000 miles! So I’ve probably done 8000 ish since I noticed it I don’t even worry about now.
Wow. Mine hasn't even reach 8000 miles yet so maybe it'll survive. Yeah just tiny little bubbles and only when it gets up to temperature. Maybe one bubble every 10 seconds. Would love to know how many other superquadros have this symptom... And if anyone has got to the root cause. I guess it can only be the head gasket or head.
Hmm I don't do water cooled bikes but if it was mine Id be checking the head/barrel bolts were tensioned to correct spec...Also maybe if there is a gap between the mating surfaces and water can get in its nothing more than it boiling off
A little update on this for peoples reference in future. I decided to look further into this by checking for head gasket leaks. I've used a coolant combustion leak detector which has come back positive. I'm also getting some bubbling from the coolant system with the radiator cap off, particularly when giving it a small amount of throttle. So it would seem that the head gasket is gone and it's possible that the external bubbling is just one symptom of this issue.
That’s interesting. Mine definitely doesn’t bubble from the coolant or pressurise it at all. I’ll do a leak test now though . I did find a few posts on various sites about the fizzing at the gasket at the time I noticed mine, I’ll see if I can them again. Good luck with the repair.
Maybe a shout out to @nelly for some guidance? If bubbles can get out, then you have lost any gas tight seal and if air can get out, then presumably air/water/oil can get in, which is never a healthy recipe for an engine.
