Yes, recommend you tear down the carb and verify clean and float set
properly.
Clean the head and piston good.
Install new plug
Run brand name gas and OMC, Merc, or Yamaha oil TCW3. Cheap oil tends to
not burn properly and cause carbon buildup.
The amount of oil and gas you burn in that engine - you won't save any real
money on cheap oil.

--
Tony
My boats and autos - http://t.thomas.home.mchsi.com



"Jan" wrote in message
...
Hi,

I found after I pulled of the cylinder head a lot of carbon (kind of
wet) on piston and cylinder head, could this cause a problem as well?

Many thanks,

Jan.
(Honda CB 400N '79)
(Honda CB 750 Sevenfifty '92)
(Yamaha TDM 850 '98)