chattering dizzy

[jimbob-mcgrew]

what causes these to chatter away ? (mines bloody loud)

can they be repaired ?

:thumb:

[marc69]

What enigne is it from? If it's the black ohc one, perhaps the springs have slackened and the wieghts are moving too much? Just a guess.

[torquey]

Yes its the advance weights the springs wear. Is it a 1.2 carb model by any chance? Just done mine as mine was loud. New dizzy was in order.

[millworm]

Do remember hearing that a ticght cambelt makes them noisy? Don't understand how tho

[jimbob-mcgrew]

yeah 12ST, black cap type - 1.2 / 1.3 engines

ahh, i didnt think about the springs.
i thought it might be play in the main shaft.

ill try tighten then up, or replace if need be, and see what happens :thumb:

[jimbob-mcgrew]

Do remember hearing that a ticght cambelt makes them noisy? Don't understand how tho

waterpumps squeel there tits off with tight belts, might be that ?

[millworm]

Certian they where talking about the dizzy, maybe it's all these years of inhailing brake dust and fumes lol

[jimbob-mcgrew]

heheh maybe, ive lost the plot myself. im running a 5-10 second gold fish memory these days lol

[meritlover]

it's not just the weights. theres a bush on the shaft which the rotor arm is bolted to. this wears and the rotar arm/cap chatters and when really badly worn, smashes rotor and distributor caps.

its pretty obvious when you take the distributor cap off and look at it.

[Novasport]

I had this problem on my SR. I removed the dizzy and could find no play in the shaft or weights. I tried another dizzy and it was still the same. The noise was definitely from the dizzy too.
Somebody mentioned a slack timing belt could cause the issue which I was a bit dubious about but it was easy enough to check and I had nothing to lose.
I knew that the belt and water pump had been replaced by the previous owner so thought it would be fine but on checking I found it was quite slack.
I tensioned it up correctly on the water pump and fired it up. It bloody well cured the rattle too!

[millworm]

^ I knew I wasn't insane

[jimbob-mcgrew]

i think your both nuts lol

mind you, saying that, i just changed the water pump / cambelt / thermostat, before it started chattering, but the original belt was on there so tight, it was making the waterpump squeel, and probably drowned out the chattering noise, so i didnt notice it.

hmm, i will give the dizzy a good checkover anyway, to see what the score is.

[jimbob-mcgrew]

i checked this out earlier.

when the rear plate moves (that controls the weights) the weights dont move in synch. the lower one moves quite alot before the top one does anything, and the edge of the lower weight catches on the top weight, and makes a ' chink ' noise that i think is the chattering.

when the top weight is moved first, they both move in synch without catching.
when the lower weight is moved first, they catch at the edges, and the top weight never reaches maximum movement.

i checked the springs over, they both have good tension, and tried swapping them to check (no problems there)
i cleaned everything up to see if there was any resistance on one side (no problems there)
i examined the weights side by side, for any deformities (no problems there)
i measured the spring control bar, behind the weights, to see if it had wear on one side, causing the top weight to fall behind (no problems there)

the problem must be further back, as the top weight doesnt get to maximum extension when moving the control arm mechanism, behind the spring bar.

anyone got any idea's, before i strip it all down to investigate.