24 replies to this topic

[corsicanwood]

Hello guys.

I am working a lot on my mini recently, I just acquired a strobe light to adjust timing if needed. The strobe is the same as the accuspark SP8000

The car is a 1981 998 stage 1 (AAU needle, kn filter in the original airbox and maniflow exhaust).

I’ve set the idle timing @ 10 degrees BTDC, vacuum unplugged. No problems here.

When checking total advance @4500 rpm, the flash happens to show 2 marks at the same time, roughly between 28 and 38 degrees. (See photo, strobe light set to 30°)
Tried to isolate the n°1 HT lead from the others to minimise interferences, reposition the spark sensor,… same result.

Some people including Keith Calver advised me to check the timing chain, as it was likely to be very slack.
Ordered a new tensioner and gaskets and started digging : timing chain was (and still is) ok, no slackness at all and pinions seemed okay too.

Disassembled the distributor : contacts are set to 0.35 to 0.4mm, springs are in the right place and both the weights are free.
A lot of play when pulling/pushing the distributor central pin (1-2mm), and a very slight play when moving it from left to right.

The car starts and drives ok, but lacks power overall especially on the high end. So maybe a new dizzy is the way to go ?

From a lot of research, I’ve found that Lucas distributors are regarded as quite reliable and couldn’t find any topic with the same issue as mine.

Thoughts ?

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Edited by corsicanwood, 21 January 2026 - 03:00 PM.

[panky]

Could be that the strobe is reflecting shiny marks on the pulley, does the mark you highlighted show at the same time as the two anomalies?

[corsicanwood]

The white mark is the only mark on the pulley!
But I can see it twice when the strobe is flashing.

Idle is fine, the mark is in front of the 10° tooth and does not jumps. but at 4000-4500 rpm it’s impossible to measure because it seems to jump from 28 to 38 at each turn of the engine.
So I can « see » two marks while the strobe flashes, instead of one

[alpder]

This question seems similar: https://www.theminif...=+timing +flash

[corsicanwood]

Oh, nice one, thanks. It looks like the same issue… Will try to measure with the strobe set to 0 and report here

[68+86auto]

What is the dwell? Is it stable?

Does the vacuum advance change the dwell by more than say 2 degrees?


Ideally you would get the distributor tested on a distributor machine and repaired if necessary. There are numerous issues with the new ones.

[Earwax]

Some distributor dog drives have too much play  - getting old?

[corsicanwood]

Don’t know the dwell angle as I don’t have a tester. I set the contacts using a feeler gauge and that’s it

I don’t think there are any old school mechanics in my area, so I’m stuck with DIY for this !

@earwax, you might be right. Or/and or lots of play in the dizzy shaft. Will test everything I can in the next days

Also, I can grab a brand new Powerspark distributor for a good price, but the seller says it’s the generic A+ version. (Not suited exactly to 998 or 1275, it’s more of an all-rounder curve for every a+ engine). Anyone tested that ?

Don’t know the dwell angle as I don’t have a tester. I set the contacts using a feeler gauge and that’s it

I don’t think there are any old school mechanics in my area, so I’m stuck with DIY for this !

@earwax, you might be right. Or/and or lots of play in the dizzy shaft. Will test everything I can in the next days

Also, I can grab a brand new Powerspark distributor for a good price, but the seller says it’s the generic A+ version. (Not suited exactly to 998 or 1275, it’s more of an all-rounder curve for any a+ engine). Anyone tested that ?

Edited by corsicanwood, 22 January 2026 - 07:34 AM.

[gaspen]

 

Don’t know the dwell angle as I don’t have a tester. I set the contacts using a feeler gauge and that’s it

I don’t think there are any old school mechanics in my area, so I’m stuck with DIY for this !

@earwax, you might be right. Or/and or lots of play in the dizzy shaft. Will test everything I can in the next days

Also, I can grab a brand new Powerspark distributor for a good price, but the seller says it’s the generic A+ version. (Not suited exactly to 998 or 1275, it’s more of an all-rounder curve for every a+ engine). Anyone tested that ?

Don’t know the dwell angle as I don’t have a tester. I set the contacts using a feeler gauge and that’s it

I don’t think there are any old school mechanics in my area, so I’m stuck with DIY for this !

@earwax, you might be right. Or/and or lots of play in the dizzy shaft. Will test everything I can in the next days

Also, I can grab a brand new Powerspark distributor for a good price, but the seller says it’s the generic A+ version. (Not suited exactly to 998 or 1275, it’s more of an all-rounder curve for any a+ engine). Anyone tested that ?

 

 

Get a multimeter with dwell function, these are not that expensive

 

Maybe your engine will run better with the Powerspark (choose the electronic version) but there is no "all-rounder" curve 

[Steam]

Can you hear a blip or hunt as the marks move, I had an engine that did this and could hear a distinct hunt as the marks moved.

[corsicanwood]

That’s the one : Powerspark D10. https://simonbbc.com...KXxpWgyUO0lUWFU

Simon from Powerspark confirmed to me that this dizzy is an all rounder for all a+ engines

D10-98 is optimized for 998 minis, and D10-75 is for 1275 engines. D10 is the generic one and that’s the one that is for sale in my area

@steam I don’t think so. The engine sounds quite linear, no hiccups or misfires and maintains 4000 rpm without any issue

[PoolGuy]

Simon from Powerspark confirmed to me that this dizzy is an all rounder for all a+ engines

D10-98 is optimized for 998 minis, and D10-75 is for 1275 engines. D10 is the generic one and that’s the one that is for sale in my area

 

Oh dear. IMO any distributor that's ok for a 1275 won't be any good in a 1098. If Simon from Powerspark genuinely said that there's an 'all rounder' I'd steer clear of Powerspark. I'd like to think that something has been 'lost in translation'.

[corsicanwood]

1098 is a-series not a+, but you’re right. The engine will certainly run but it can’t be ideal

[NLinPEN]

You seem to be looking for faults in your engine. However, it could also be that there is a fault in your timing light. It is possible that it is not able to track rpm properly at higher rpm due to some malfunction of the electronics in the timing light. Have you tried this timing light on another car?

Reason for me to bring up this possibility is that I have an Innova timing light that worked fine the first couple of years, and then started to develop weird behavior at higher rpms (approx. 3,000 and above). I have yet to figure out what's wrong with it though.

[weef]

If you are not experiencing any engine running problems that such a shift in ignition timing would suggest, I would be checking the integrity of the crankshaft damper pulley, as the rubber can deteriorate over time.