Speedo only works when engine braking!
 

Very odd. I am thinking that it could be something about the distance between the sensor and the cog wheel? Anyone with similar experience?

The speedo sensor (runs from loom to back of engine case nr rear CCT) when it's on on the way out can seem randomly sporadic.

Best to be sitting down when you find the price for new one. Keep an eye on ebay for a second-hand un.

Thanx. Is there some way to test if it's gone?

Could try cleaning the connection where it plugs into the loom, underseat nr battery IIRC. If it still plays up, jumping around/dropping out, replace with a known working speedo sensor.

Found new OEM at USD 55. Quite ok I think.
Cheers

Here in the UK the sensor costs new £122.79 / $195.99 / € 151.08.

Where did you find yours at that bargain price?

here: PowersportsPlus.com - OEM Powersports Parts from Honda, Kawasaki and Yamaha at discounts up to 80% off MSRP

I have used their services often. Especially for small items that are missing when buying parts on eBay.