Engine check post BoB

[Skunk]

Was the carb sucking water thrown up by the back tyre?.......

Nope. Open carb but it's protected from that sort of thing.

[Skunk]

So I can't see any damage. So no nip up? Check the carb, any blockages of pilot jet etc?

[edit] from reading above, so did you find water or gunge in the fuel?

No nip up. Carb is fine apart from the cause... No jet blockages.

[Skunk]

You pretty much got it Dave.
The bike has a fuel filter. A very fine mesh one.
A 'new' old fuel tank has been fitted. The filter is letting very fine iron 'powder' into the fuel system and burning it. You can see the build up around the plug.
The 'nip-up' was the spark plug failing to fire properly due to short circuiting. My guess is that as the BoB was a longer race than the bike has done before the iron had time to build up without cooling down and breaking away.
Time to seal the tank I think.

[F5 Dave]

Suzuki tank. They always do it. Best to seal in warm weather or a hot water cupboard, but it would smell it out. An old vacuum cleaner on blow helps airflow.

[Yow Ling]

Well thats kinda interesting, the plugs in my lc get like that after a couple of years, so now i know whats going on Thanks