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81 CB650 - Deposits on pistons

Posted: Sun Dec 11, 2016 11:00 am
by brixie387
Long-time rider with basic knowledge of engines, attempting my first engine surgery to replace a leaking head gasket on this recently-acquired bike. Everything is going smoothly so far thanks to this forum and YouTube. Upon removal of the head I have found that all 4 pistons have heavy deposits on them, but the spark plugs look good - see photos. Is this a normal level of deposits? Or do I have other issues to address?

I have not ridden this particular bike enough to tell if it burns oil, but there is no obvious heavy smoking from the exhaust...

Thanks in advance for your help!

Re: 81 CB650 - Deposits on pistons

Posted: Sun Dec 11, 2016 11:45 am
by cb650
that looks normal. might be worth doing valve seals as the head is off

Re: 81 CB650 - Deposits on pistons

Posted: Tue Dec 13, 2016 12:48 pm
by MEHall
Do you have any manual? I think it says you dont need to bother with the deposits on the top of the pistons, unless it intefers with anything else like the valves. :roll:
I would say that the only thing that can be an issue is any type of leakage like leaking piston rings or any heavy oil leak. :wink: :roll: