This late model Kawasaki ZX-9R has only done 3,000 miles from brand new and, as you’d, expect is in beautiful condition. However it represents a problem that we see time and time again coming through the workshop – the fuel left in it has turned to varnish in the carbs, clogging them completely. They needed stripping and cleaning; typically, where this bike had been stood one carb had less fuel than the others, and as it dried out the residue gummed everything up. In extreme cases you’ll need a new bank of carbs, and it’s not the jets or needles that are the problem but the air bypasses in the cast body – once they’re blocked, it’s game over.
Petrol these days is effectively useless after two months so if you don’t do a lot of miles on your bike the best thing you can do is use a product by Silkolene called Pro FST – it’s a fuel additive that will stop petrol deteriorating. For everyday running you add a very small amount – 1-2% – but prior to laying up the bike put about 500ml into a full tank and run it through to make sure it’s in the carbs or injectors. It’s much cheaper than a carb or injector strip and clean, trust us…