DanClarke said:

OK, so here are the very sooty BP6ES plugs. All equally awful, no special standout cases.
View attachment 343227
I shall pop some BP5ES's in (hotter plugs I think). I hope they don't do any damage, and it might burn off the carbon.

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Sooty and oily ....

Hold them in a pair of pliers over an open flame, gas cooker hob if the missus isn't looking, see if it cleans them up a bit ...

Dippypud said:

Sooty and oily ....

Hold them in a pair of pliers over an open flame, gas cooker hob if the missus isn't looking, see if it cleans them up a bit ...

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Yes, I used a map gas torch.

But the switch to BP5ES plugs has not resolved the sooting up problem.
Which means it is probably running too rich for them too.

It's not the plugs, it's either burning oil or tooooo rich

landowner said:

It's not the plugs, it's either burning oil or tooooo rich

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I think it is the latter of the two. I think I will pull the "custom needle" and put a standard BDL in there.

DanClarke said:

I think it is the latter of the two. I think I will pull the "custom needle" and put a standard BDL in there.

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You can always file a bit off the BDL if you loose power top end

landowner said:

You can always file a bit off the BDL if you loose power top end

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In the past where the vehicle has bogged down with a BDL needle has been in low RPM going up to mid-range RPM so maybe a bit off the part-throttle area.

DanClarke said:

In the past where the vehicle has bogged down with a BDL needle has been in low RPM going up to mid-range RPM so maybe a bit off the part-throttle area.

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Sounds like a plan, either small file and file a tiny flat middle of needle or you can use Brasso to remove tiny amounts off till you get an improvement, could be lean at top end though and rich lower down, that would give black plugs if you're not flat out all the time. Not easy so trial and error is the best way
I used to have a box of various needles from scrapyards but not as easy to get these days

DanClarke said:

I think it is the latter of the two. I think I will pull the "custom needle" and put a standard BDL in there.

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WHY!!!!????

Simply weaken the mixture at the jet, by winding the jet up a lickle bit??

Going back to a needle that didn't work in the first place won't help, and filing anything off anywhere will simply richen the mixture at that point.

Richening it is the opposite of what you want and you cannot weaken it by adding brass on!!

KISS!!

(No offence meant!)

Stanleysteamer said:

WHY!!!!????

Simply weaken the mixture at the jet, by winding the jet up a lickle bit??

Going back to a needle that didn't work in the first place won't help, and filing anything off anywhere will simply richen the mixture at that point.

Richening it is the opposite of what you want and you cannot weaken it by adding brass on!!

KISS!!

(No offence meant!)

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And no offence taken, of course.
Before the "tune" the soot problem with a BDL needle was pretty much non-existent, but it did not run very well in the part-throttle range it would pop and bang if you tried to accelerate too rapidly.
After the tune and the replacement of the BDL needle with a highly modified needle the running is fine but the plugs are sooting up.
So maybe (just maybe) the answer lies somewhere in between?
Possibly a modified BDL needle with attention having been paid to the part-throttle area?
I'm going to leave it in its "Tuned" config for now but I am concerned it might be just washing the rings out with fuel.

DanClarke said:

And no offence taken, of course.
Before the "tune" the soot problem with a BDL needle was pretty much non-existent, but it did not run very well in the part-throttle range it would pop and bang if you tried to accelerate too rapidly.
After the tune and the replacement of the BDL needle with a highly modified needle the running is fine but the plugs are sooting up.
So maybe (just maybe) the answer lies somewhere in between?
Possibly a modified BDL needle with attention having been paid to the part-throttle area?
I'm going to leave it in its "Tuned" config for now but I am concerned it might be just washing the rings out with fuel.

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OK, get all that.
But as long as you make a note of how much you back the mixture off, I don't see how that would be a concern. sure it'd weaken the mixture across the range but they often leave it running a little rich. It is obviously tuned on the "performance" side, even if just a tad.

all I know is, that if it was me, that is what I would try first.
Does your oil smell of petrol?
Of course you could take it back to them, they got your money after all, and ask them about it.

Best of luck, I know one could get a bit hyper about this, but they are pretty robust machines.

Stanleysteamer said:

OK, get all that.
But as long as you make a note of how much you back the mixture off, I don't see how that would be a concern. sure it'd weaken the mixture across the range but they often leave it running a little rich. It is obviously tuned on the "performance" side, even if just a tad.

all I know is, that if it was me, that is what I would try first.
Does your oil smell of petrol?
Of course you could take it back to them, they got your money after all, and ask them about it.

Best of luck, I know one could get a bit hyper about this, but they are pretty robust machines.

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Thanks for the patience with this lad Stan, much appreciated.

Having tried BPE5 plugs to no avail (except the introduction of pre-ignition) I did a few things.
1. I put the BPE6 plugs (cleaned up with a gas torch) back in.
2. I popped the top off the SU Carb and reset the jet to the recommended "starting point" for tuning.
3. I swapped the heavily filed "Custom Needle" [god it had been hacked about] and put a stock BDL needle back in.
4. I ran it till it was at normal operating temperature then set the idle revs and made the jet adjustment as per the SU manual and then reset the idle speed on the idle screw.

I have been out for a blatt around the town just now and up that hill a couple of times, no performance or any other issues. Got home and it was idling rock steady and not missing a beat.

When it is cooled down I will pull a plug and take a look.

Now it went to that tuner with a BDL needle in it and it was problematical at that time.
One of the other things he did change as well as the needle and the "tune" was he changed the coil and declared the one in there was for a contacts ignition and NOT a high power coil for contactless ignition.

So, it is potentially possible that my original problem was the "wrong" low-power coil and the BBA needle it came to me with or the BDL needle I fitted would have all been fine with the correct coil.

I really don't know.

I am a novice in these matters, but I can convince myself that this scenario is what has been happening.
What I can say for sure is that the "Tuners" idea of a tune was just all excess petrol for max BHP with no regard to engine longevity. "Bore-Washing-R-Us".

I shall wait and see how it goes over the next week or so.

Bread and cheese hill ? or the one on Essex way ?

freelance said:

Bread and cheese hill ? or the one on Essex way ?

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EsSEX way.

freelance said:

Bread and cheese hill ? or the one on Essex way ?

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Love the names of places . Bit like cheesefoot head