Little bit black

[K B]

KB here, I'm eager to ride my 73 cb750k3 again after a long winter. I rebuilt the clutch, got a new front tire, and actually drilled holes in the front brake disc.
Test drove it and runs and stops great. No squeeky brake now.
One problem,

now the #1 cylinder has some blow by around the head and fins are a little black. The bike has almost 40k miles and no major enj. work. I will do a compression check and tune up, oil change, ect... do you guys think it's safe to run for a while before delving into the reason for black junk? Not real much, it's by exhaust right at the head. Just the one cyl.

Runs smooth and strong.

 

[brettp]

Are you sure it isn't just an exhaust gaskets that quit?

 

[Surf Dog]

KB here, I'm eager to ride my 73 cb750k3 again after a long winter. I rebuilt the clutch, got a new front tire, and actually drilled holes in the front brake disc.
Test drove it and runs and stops great. No squeeky brake now.
One problem,View attachment 20076 now the #1 cylinder has some blow by around the head and fins are a little black. The bike has almost 40k miles and no major enj. work. I will do a compression check and tune up, oil change, ect... do you guys think it's safe to run for a while before delving into the reason for black junk? Not real much, it's by exhaust right at the head. Just the one cyl. View attachment 20075Runs smooth and strong.

Mine seeps oil from the head gasket, it's been doing it for decades. It's a known problem, the only fix is to replace the head gasket.

 

[K B]

Mine seeps oil from the head gasket, it's been doing it for decades. It's a known problem, the only fix is to replace the head gasket.

Surf Dog! Thanks for post! Yeah I am going to run a while before getting too freaked. I was told to change oil often as well. Have Fun