Thanks guys. This has been very interesting. cheers.

[NJK-5002C]

Sensors - extra, and are again available from China as multi buys at really low prices.
Its doubtful you need a sensor "desperately"! 

Search for NJK-5002C (it's a common industrial sensor - other 12v Hall sensors should also work).

Sensors - extra, and are again available from China as multi buys at really low prices.
Its doubtful you need a sensor "desperately"!  [size=78%] [/size]

From the description in the ad you'd have to get the hall sensor, they're not expensive, still a good price.

Looks OK. Does it come with the sensor or is that an add on? last question 

85mm Tachometer Tacho Meter Gauge LCD Hourmeter 0-4000 RPM For Car Boat TruckOpens in a new window or tab

Less than £25! Perhaps rather frail but we'll see.
I hope this link works from Ebay (China) but doesnt take long. Various ranges available with hour meter. Cheaper than "marine alternatives" which may or may not be marine. Usual magnetic (Hall?) sensor set to about 40 degrees

Thanks. Where did you find it? Flea-bay has similar but Brand Names & $$$$. thanks again.

Its just a full deflection Tacho 0---4,000 as the B+S engine only runs up to 3,400 rpm, with sensor NOW tilted around 40 degrees towards the approaching flywheel magnet. Works fine now as I get an early warning should the belts skid with moisture, and thus avoid engine over rev..
It also looks cool! 

Thank you, really enjoyed this. Great to see Jack taking the helm.  You peaked my interest with the new tacho.  Info please.  . cheers.

Film of the visit early April with John and my grandson Jack.
Please remember the built in length adjusting modification tab (off button)






https://youtu.be/YbgUuyXnoKQ