Spark plugs

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ttwlr
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Spark plugs

Post by ttwlr »

Hi All,
Took my car for a drive, all seams good, thought I would check plugs, in pictures it's 1 from front working way back, is this a normal look for the plugs, or is it running ritch ?
Also brake squeaking bad, if I had push it ok,
Thank you



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svenedin
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Re: Spark plugs

Post by svenedin »

To me the electrode colour looks quite close to being correct, but a bit rich which might be half a flat of the carburettor mixture nut or slightly more. However, there's quite a lot of soot on the plugs which suggests short journeys running on choke and not much time for that to burn off after the choke is put back in or the engine is burning a bit of oil. Is the exhaust smoky? Does it have the characteristic exhaust smell of an engine burning some oil?

Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
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geoberni
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Re: Spark plugs

Post by geoberni »

I'd say not looking too bad, but #2 looks sootier than the rest.
A lot depends on the type of driving you've been doing, as Stephen said, has it been on Choke a lot?
When was the air Filter last changed?
I personally find mine is generally off the Choke within a couple of miles or so.

See this website for a quite comprehensive list of potential Plug appearance: https://www.autolite.com/media/wysiwyg/ ... g_Tips.pdf

I was going to give you a link to the Champion website, but they only show 7 images... :roll:
Normal, Sooty, Oily, Wet, Burnt, Worn and Broken.
Basil the 1955 series II

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myoldjalopy
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Re: Spark plugs

Post by myoldjalopy »

Re the brakes, often brake dust in the drum will cause a squeal. I had this only last week in the front nearside drum. Removed the drum, brushed away the brake dust and cleaned the shoes and drum with brake cleaner for good measure. Squeak gone now.
Not knowing anything about your car's history, just be aware there may be asbestos dust from the shoe linings if they are very old, so take care............
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svenedin
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Re: Spark plugs

Post by svenedin »

Yes agree completely. Clean dust out of brake drum. Do not blow it around in case the brake lining contain asbestos. Remove drum, spray with brake cleaner, wipe clean with garage tissue and dispose of tissue in the bin. Another possibility is that the brake linings are worn down to rivets. If that is the case, check the drum for scoring and replace the brake shoes. Always buy decent brake shoes. Avoid unbranded shoes. The Minor hardly has earth shattering brakes at the best of times!

Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
ttwlr
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Re: Spark plugs

Post by ttwlr »

Thank you for the replys, I only used choke to start it, then push it back in after a minute, then let it run a bit before driving it, I've only been doing short journeys as just got it on the road, the brakes are new but hadn't been used for a few years, but they were cheap shoes, so not sure if this was the issue.
I will clean the brakes and see if this helps, but I want to get decent shoes etc, but don't want to get disc conversion as I like to keep it original.
I just been enjoying driving now, and weather was nice today so had an hour pottering about.
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svenedin
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Re: Spark plugs

Post by svenedin »

When you get a chance to do a longer run check the spark plugs again and adjust the mixture as indicated by the plugs. You are close to the right mixture so it is only going to be a tweak. The mixture nut (the lower of the 2 nuts) only needs small adjustments once you are in the right ballpark. You could adjust 1/2 a flat towards weak (turn nut anticlockwise when looking from above). Before you adjust the mixture nut you must disconnect the choke cable or it will stop the jet moving up or down. All you have to do is loosen the pitch bolt, you do not need to pull the cable out from the linkage. The pinch bolt head is 5BA and a 5BA socket just used in the hand is perfect for the job.

Unfortunately, Mintex/Ferodo have stopped making both front and rear brake shoes for the Minor. Sometimes you can get new old stock shoes so keep an eye out for them. ESM sell "Apec" branded 8" front brake shoes but they no longer sell branded rear 7" brake shoes. Another brand that are very good are Delphi but again these are no longer made.

Parts such as branded brake shoes turn up at club branch sales, garage clear outs, auto jumbles etc. Most of us have a tendency to horde parts.....

If you really want you can have brake shoes re-lined with excellent friction material but this is expensive.

Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
ttwlr
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Re: Spark plugs

Post by ttwlr »

So are mintex the ones to go for, and is this same for cylinders, ?
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svenedin
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Re: Spark plugs

Post by svenedin »

ttwlr wrote: Mon Oct 06, 2025 9:27 pm So are mintex the ones to go for, and is this same for cylinders, ?
Mintex/Ferodo are my favourite and have been since I first had my Minor 36 years ago. I know that other members also rate them highly.

With cylinders buy the genuine ones from ESM. These are branded Lockheed or Lockheed Delphi as is the master cylinder. I have heard horror stories of pattern cylinders suddenly leaking catastrophically with the result of no brakes other than the handbrake.

When using standard brake fluid always make sure that you change the brake fluid at least every 2 years. This is because it draws in water from the atmosphere and this corrodes cylinders which then seize. Usually it is the rear cylinders that seize but any of them can seize. A tip is to not to apply the handbrake when parked in the garage as at least then the cylinder doesn't seize with the handbrake on. Usually the seizing happens when the car is not used for an extended period. Leave the handbrake off and chock the wheels.

If you are intending to keep your Minor for a long time, consider changing the brake fluid for Silicone brake fluid. This does not attract water so seized cylinders become a distant memory.

Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
ttwlr
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Re: Spark plugs

Post by ttwlr »

That's some good information, thank you, I put the Lockheed master cylinder in mine, so I'll definitely get the same for the brake cylinders.

Appreciate your help ☺️
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