The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: PaulC on 09.05. 2016 09:53

Title: Sooty plug
Post by: PaulC on 09.05. 2016 09:53
Hi all,

I'm in the trial and error phase of getting the mixture right. Rather than using a new plug for each run after a carb setting change, how can I best clean the plug of the sooty deposits so I can re-use it?

Grateful for any advice.

Thanks
Paul
Title: Re: Sooty plug
Post by: duTch on 09.05. 2016 10:26

 I've been having a plug issue the last few weeks, I didn't bother cleaning anything; I just put it back in as-was, and figured it'd clean itself. Maybe not the right way to do it, was fine at road speed above idle, but just kept dropping out on the left no matter how I switched things. I finally changed the plugs to a newish but pre-used set of BP6ES and seems better- didn't clean those either but they work ok *dunno*
Title: Re: Sooty plug
Post by: Greybeard on 09.05. 2016 10:28
Historically I have always held the plug up to my bench wirewheel to clean them, however recent posts here have said that modern plugs do not like that sort of treatment. Let's see what the sages come up with.
Title: Re: Sooty plug
Post by: BSA_54A10 on 09.05. 2016 11:25
Easy way is to forget it and buy a color tune and go pro camera.
Fit the color tune and go pro then go for a ride round the block.
keep it short no longer than 10 to 15 minutes or you will cook the color tune.

To clean the plugs you heat them up with a lean flame oxy torch.
Title: Re: Sooty plug
Post by: a10 gf on 09.05. 2016 15:00
^^^ this
Quote
lean flame oxy torch

or maybe some petrol and a soft bronze brush.
Title: Re: Sooty plug
Post by: RichardL on 09.05. 2016 15:42
Not saying its right, or even OK, but I do as GB and just kiss the metal parts of the plug with a fine wire wheel in my bench grinder while avoiding the ceramic. This will clean off soft and hard carbon deposits enough for testing purposes. When you've resolved the issue, replace the plugs. They're cheap.

Richard L.
Title: Re: Sooty plug
Post by: muskrat on 09.05. 2016 19:52
If carby clean won't get it off I sand blast mine between plug chops. Once I'm happy they get binned and new plugs are used.http://www.amazon.com/Central-Pneumatic-Spark-Plug-Cleaner/dp/B004SBBNX0
Cheers
Title: Re: Sooty plug
Post by: PaulC on 10.05. 2016 10:09
Thanks all.

I'll try the petrol and bronze brush route first as I don't have the wherewithall to try any other method.

Paul
Title: Re: Sooty plug
Post by: duTch on 10.05. 2016 10:56
Quote
I've been having a plug issue the last few weeks, I didn't bother cleaning anything; I just put it back in as-was, and figured it'd clean itself. Maybe not the right way to do it, was fine at road speed above idle, but just kept dropping out on the left no matter how I switched things. I finally changed the plugs to a newish but pre-used set of BP6ES and seems better- didn't clean those either but they work ok *dunno*

 What I didn't say, is that I've only been doing this recently. In the past I've used a piece of metal thin enough to get down inside to scrape everything clean and tapping or blowing it out (just be careful not to get too close), but going gentle on the ceramic bit, have also used the brass brush.

 Actually, if I may take a quick step sideways; I've often wondered about the S.plug threads? It's easy to think they need lube or antiseize, but that would only reduce their connectivity powers. I generally leave them dry, but sometimes they feel angry going in /out like that.. *????*

Title: Re: Sooty plug
Post by: Greybeard on 10.05. 2016 11:03
...I've often wondered about the S.plug threads? It's easy to think they need lube or antiseize, but that would only reduce their connectivity powers. I generally leave them dry, but sometimes they feel angry going in /out like that.. *????*
I agree. I use copper-slip on the threads. I like being able to spin the loose plug in/out by hand. The sealing washer will make excellent connection with earth so I don't see that a greased thread is an issue.
Title: Re: Sooty plug
Post by: hdawson on 01.08. 2016 09:23
I agree with Trevor.
I had mad plug fouling problems both with BSA and Matchless but after purchasing and using a colortune all is well and the plugs are a healthy brown.
Simple to use and make sure you buy the thread extension.
Rather expensive for what you get but you can make your own. I think the details are on the forum somewhere or on the web.
Or maybe buy one with a couple of mates.
I also bought iridium plugs  but now it seems the BRP6ES do just as good a job.
One of the most useful diagnostic tools I have ever used.
Cheers All.
 
Title: Re: Sooty plug
Post by: Triton Thrasher on 01.08. 2016 10:03
Anti sieze compound is a good idea for plugs in alloy heads.

There will be no effect whatsoever on "connectivity powers."
Title: Re: Sooty plug
Post by: Triton Thrasher on 01.08. 2016 10:05
I happily use a hand wire brush to clean plugs.

Fit a new needle jet, before messing around trying to remedy a rich mixture.
Title: Re: Sooty plug
Post by: hdawson on 01.08. 2016 11:11
Wise advise Triton.
I am not a mechanic (far from it) and I have always been unable to get the fuel air mix right.
Even with rebuilt carbs.
I think this idea/product is great.
 
Cheers