The three most hated letters T P S !!!!

[coeurdelion]

A little insight into the TPS, there is no  hard and fast rule with them failing like most electronic parts. They are are variable resistors and work using a wiper rotating across a carbon track and from continuous use can wear the carbon track or the wiper weakens and does not make with the track correctly. I have come across a smalll number where water has seaped in through hairline cracks  This setup is used in many items most common ones are a volume control in a Radio, the fuel sender in the petrol tank of many cars and bikes or the remote control  in some game consoles.
The TPS is sealed on bikes for obvious reasons

See pics, which are courtesy of engineers garage as I dumped the old ones I had since they are rarely repairable.They show how they operate and the make up

The usual reason the fuel tank ones fail is from wear on the lever mount which can be fixed.

There are spurious one available, but unless they are a reputable brand eg.Tourtec keep away from them.

Some honda Transalp 700 fuel sendeers fail and are part of the fuel pump which is over €700. Some of these can be repaired also as it is from float lever wear.

Just be glad you don't own an Alpha Romeo as like many cars have a TPS and are are part of the Throttle body. When they fail you have to buy the full throttle body. The Alfa ones are a very common failure with a throttle body costing 1000s. There used to a fellow in the UK who did repair them but not sure if he still is around.

Brilliant info as per usual mate, and a great insight into something so simple yet if they go wrong your bike starts running like shite. 

Thanks for the indepth explanation on the dreaded TPS ,still not sure if its a necessary part of a carburatored  engine or just some other way to get you to keep paying after you've bought the bike,my old man only ever bought bog standard cars,nothing fancy as he said there's more stuff to go wrong ,if it wasn't for the fact that the rev counter needle was jumping from 5000 to 3000 to nothing on my way back from a rainy damp  camping trip then I wouldn't have known the TPS was faulty.
Coeurdelion