On a couple of my lightwins I decided to pull the exhaust cover and cylinder head in order to clean the various passages. Those passages are TINY! and it takes a bit of poking and probing just to figure out where all the openings are.
There is also a potential problem area where the water tube meets the powerhead; there’s a rubber grommet thing there with a 90 degree bend. All things you can check. See #12 on diagram.
