Rev Counter stops At 1200 rpm

[jcparsonage738]

Hi,
I’m new to classic car ownership and I am working through some minor niggles on my 1968 V8 250.

The tacho is clipping at 1200 rpm. I am awaiting some croc leads so that I can measure the generator output - but whilst I was checking the wiring, I noticed that the generator housing was a bit wobbly and covered in oil. (So the shaft with a pinion that drives the generator can be moved)

Is it supposed to move? If not, where do I tighten it?

Thanks

[jcparsonage738]

Thought I’d answer my own question.

Having looked at photo’s of the distributor housing on eBay I was able to conclude that mine was missing a retaining screw. So the rev counter pinion wasn’t supposed to move.

I bought a replacement housing and whilst dismantling the old one (removing rev counter generator), I realised that my generator was goosed.

So I now have a running car again. My rev counter still clips at 1200!! I suspect that the rev counter generator has been broken for a long time and I have semi seized clock. Next job - remove clock and attempt to lubricate.

[PPV]

Not sure why the rev counter in the car should 'clip' at 1200rpm as it is purely dependant on the signal from the generator. Not sure what 'clip' actually refers to but it sounds like yor generator is not fully engaged. You say that you have done some work on your generator but how do you know it is working properly? It should be generating about one volt per100rpm according to the manual (measured with an A.C. voltmeter).
Then check the wiring for continuity in case it is rubbing somewhere.

[jcparsonage738]

Thanks for the reply Paul.

I have checked the voltage and saw it go from 6 to 10 VAC when I revved from 500 to 1000 (on the rev counter).

I will pursue your slipping / engaging suggestion.

[PPV]

Hi, I think there should be 3 screws and a half round collar holding it in. The reason I mention it not being fully engaged is that when I got mine someone had not got the 'pegs' on the generator aligned with the shaft that drives it and had tightened the screws and it destroyed the generator. Did you measure the votage at the generator or at the rev counter?
Best of luck.