Bits getting in the carburettor.

[alanp]

Just thought I'd let you know about an experience a friend of mine had. He was on a Villiers twin with the throttle wide open (as you need to) and the engine went bang and he drifted to a halt with the clutch disengaged. He was transported home where he found a hole in his crankcase and in further investigation he discovered that a spoke had broken on his back wheel and a piece had been thrown forwards and managed to get sucked into the gaping hole of his carb, into the crankcase, jammed between the flywheel and the casing and punched a hole in it. He found the piece of spoke in the engine matching the broken rear wheel spoke.
Another friend of mine has a Triumph Bonneville which ended up with something getting into one of his combustion chambers and trashing it.
This became too real to me the other day after a long 80/85mph run on my RGS I found that the top fastener to the engine steady just above the carb had come unscrewed and fallen out. Now, I've got a mesh on my carb's inlet trumpet but it occurred to me that there must have been a risk of these bits getting into the carb.
Moral of stories - If you have a bike without a pukka filter and have a choice of carb inlet with or without a mesh gauze, get the mesh gauze or it may be your engine next time.
Have a nice day.
Alan

[Triton Thrasher]

What horrible tales of destruction.  Get a proper filter.  The mesh over the bellmouth is restrictive as well as not very good at filtering.

[bsa- bill]

Was a pillion on a Rapide once when the rider stopped  saying it wasn't going right, sounded like it was firing on one only ( I couldn't tell the difference on those Vee's), a duster tucked into a Vincent crevice had got sucked into one of the carbs.

No damage done as we were still in chug mode, I could now say I've ridden pillion on a Rapide and a Comet

[chaz]

allways use filters, ive known race bikes pick up dust and dirt small stones and hole pistons, you can even tell when there is water in the fuel when you check pistons so rain can be a problem too

[Goldy]

I see lots of British bikes without filters on and I have always thought they are asking for trouble. I will mention your experience to them.

[Duncan R]

You might see my other post regarding a bottom end rebuild - Today I found a nut in 4 pieces in the combustion chamber (minimal damage as far as I can tell) I have a screw on pancake filter so hell knows how it got in there.

[bsa- bill]

Today I found a nut in 4 pieces in the combustion chamber (minimal damage as far as I can tell) I have a screw on pancake filter so hell knows how it got in there

Or past a valve? more probably it gained entry via a plug hole

[Duncan R]

Hi Bill,

As you say via the inlet valve, maybe it was sitting in the airfilter and got sucked in