Distributor cap problem?

Can anyone please furnish me with information on the distributor cap on a 2.25 Landy engine?

Most of the caps I have dealt with in the past have some form of centre contact with the rotor arm. Mine hasn't, just a hole with what appears to be a spring loaded 'something or other' inside?
Am I missing a carbon contact and could this be why I'm running a bit lumpy, as it seems a heck of a long way for the spark to Jump!

yer carbon brush wears down over time and may not reach the rotor arm. if the center of the arm is shiney then the brush is probably ok, if its black and burnt looking then its probably too short

or yer spring might be weak but thats not likely

slob said:

or yer spring might be weak but thats not likely

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I know this sounds daft, but there aint no sign of a carbon brush!

I've just been looking at the cost of a new distributor cap and it's pennies. I fancy I'll buy one for peace of mind tomorrow.

Thanks for the reply slob!

well yer wint get a good spark without one. yer might as well splash out and get noo leads and plugs arnorl, and as it noo year go fer noo points and condensor too

slob said:

well yer wint get a good spark without one. yer might as well splash out and get noo leads and plugs arnorl, and as it noo year go fer noo points and condensor too

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Just replaced the plugs with NGK's and was working my way back from there anyway! Cheers