The tail of a motorcycle gremlin

So the tiny fragment disabled the motorcycle.

So it all started with a ride to charge the batteries on our motorcycles. My recently changed tyre had not even done the hundred miles it needed to bed in before I picked up a screw in it on the short ride that caused a hole that was beyond repair. That was a costly replacement for starters at ￡100.

But the fun did not stop there, the tyre shop was open, Formula 1st WsM did a great job of finding a match as the particular matched pair of Continental Contimotion tyres were from a range discontinued recently. But due to the lock-down there was a wait for delivery of the replacement.

So my bike was left standing in a garage until delivery, fitting and a few more days of wet weather and being busy left a couple of weeks before I could get back to refitting the wheel to the bike.

But that's when the second issue came to my attention, we had filled up the bikes on the ride out, but now a considerable amount of what had been in the tank was now on the garage floor. It's an age old issue with carburettors and gravity fed fuel systems, go back 40 years and we used to have to remember to turn off the fuel tap when leaving the bike. Also to turn it back on as part of the starting process to avoid a short ride!

The problem was that the fuel flow was only regulated by the float in the carburettor(s), the needle valves can easily be stuck open via something as simple as stale fuel. The problem was solved with the introduction of the vacuum tap. This device uses the suction provided by the cranking engine to open a valve that allows the fuel to flow.

Now mine also retains a 3 position operation, On, Reserve and prime. "On" takes fuel from a tube into the tank, while the reserve is what is below the tube height. Both only operate via the vacuum valve. While "prime" is for feeding the system should it have been drained or standing for a prolonged period. Many modern motorcycles discarding taps totally, simply using a vacuum operated valve.

Either way, my bikes fuel tap vacuum shut off was not shutting off. Some of that petrol had made it's way into the oil. So that oil and filter change done less than a 1000 miles ago also needed to be redone. Another ￡45. So what's wrong with the tap?

Now first was to strip it, clean it and check everything, well to my eyes it all looked OK and seemed to all be in working order, rebuilt, refitted to tank, still leaks.

So a new seal kit was ordered, fitted, refitted to bike, still leaks!

Ok my eyes are not what they used to be, what did I miss? Got my partner to look, Jayne has younger eyes and both of them work well, unlike mine. After closer examination she found the 2mm x 1mm metal flake in the vacuum seat. It may have even been there since the tap was manufactured over 23 years ago, just migrated slowly to somewhere where it could cause an issue? We can see no other way for it to have got in there. I should have spotted it on inspection, but in my defence, it was well camouflaged. Not sure how long the tap had not been closing properly either, could have been months.

What is learned? Size does not matter!

However well you have done the job and are sure you did it right then if it's still not working, it is only logical that you either missed something or made a mistake on reassembly. It can be hard to accept that we are fallible, but nobodies perfect.