rev counter on my willy 2

[Jay MK1]

is not working properly, the engine is going to its full revs but the clocks say it tops outs at 4k at the most, anyone know what sensor can cause this and where abouts it may be?

cheers

 

[Russ_16v]

does the revs rise progressivly and just top out at 4k amet or does the needle jump etc?

 

[Jay MK1]

it's not a sticky needle and the rev's are fine and progress like normal its just the clocks show differently