Recent Posts

51

Lucas, Ignition, Charging, Electrical / Re: Iridium Spark Plugs

« Last post by Rex on 29.03. 2025 17:39 »

I like Brisk plugs, and they can be cleaned and reused unlike other new plugs.
Particularly good in the somewhat oily environment of a Scott engine.

52

Wanted & For Sale / Re: Paddock roller starter

« Last post by sean on 29.03. 2025 15:04 »

As long as its not your middle leg 
You might try kicking with your left leg although it seems awkward to me a lot do it, a roller starter will fire the bike at home, what are you going to do if you need gas or it stalls out?
Maybe time to look at an electric starter conversion.

53

Wanted & For Sale / Re: Paddock roller starter

« Last post by Topdad on 29.03. 2025 14:58 »

Thanks gents but typo it's my right leg that's is donalded  how left got thre is pure senility!

54

Lucas, Ignition, Charging, Electrical / Re: Iridium Spark Plugs

« Last post by chaterlea25 on 29.03. 2025 13:03 »

Hi All,
While on the sparkplug topic,
Has anyone got experiences with "Brisk" sparkplugs ?

The ones suitable for Alloy head A10's are non resistor  and from what I have read about them the insulator is "glazed" as other brands were years ago.
According to "F2" motorcles (shop) in UK they are resistant to oil and fuel fouling.

I searched online for a supplier.
UK Ebay seller wants £10 each for them
F2, you need to phone as they are not an online seller
I found a shop in Germany that sells them for about € 3.50 plus VAT and post
Anyway I now have two grades 14 and 15 equivalent to B7 and B6 approx as they have a wider heat range
I bought 8 plugs and they work out about €6 each . Germany post is expensive at €20
This is shared with a friend who also wants to try them.

My SR always runs well on NGK's but they do not last very long.
After 800/1000 miles stop for a coffee or fuel
And the bike refuses to fire up again. Fit new plugs and it starts instantly. ( i have had the mag checked out, it's a proper BTH)

Time will tell how the Brisk plugs work out

John
 

55

Wanted & For Sale / Re: Paddock roller starter

« Last post by Rex on 29.03. 2025 10:23 »

I'm the same, but maybe the OP's left leg is too weak to ether kick or stand on?

56

Lucas, Ignition, Charging, Electrical / Re: Iridium Spark Plugs

« Last post by Rex on 29.03. 2025 10:21 »

If Americans pronounce "aluminium" as "aluminum" do they pronounce "Iridium" as "I ride'm"?
{Sorry }

57

Wanted & For Sale / Re: Paddock roller starter

« Last post by sean on 29.03. 2025 02:46 »

why not    use your right leg ?
 I have never used my left leg to start my bike seems awkward
roller starters are easy to make if you look at them in pics

58

Lucas, Ignition, Charging, Electrical / Re: Iridium Spark Plugs

« Last post by JulianS on 28.03. 2025 21:02 »

I used iridium resistor plugs in an ally head for about a year. Denso IW22. The bike ran well with them and they seemed to stay cleaner than the N4. But the plugs did not last for long. Bought from a reputable supplier and in the course of a year 2 of the 4 I bought had failed. And they were quite expensive. I presume they did not like working with the magneto. Tried an NGK equivalent but the bike was not happy with them. Anyway the head would not stop leaking oil from the joints so I took it off and replaced it with an iron head (which did not leak) I use Champion L6G Gold Palladium plugs on this and I prefer them to the L82c or NGKs. They have a fine centre electrode, not as fine as the iridium ones.

59

Lucas, Ignition, Charging, Electrical / Re: Iridium Spark Plugs

« Last post by CheeserBeezer on 28.03. 2025 20:05 »

I read in some Thread recently that Iridium Spark Plugs are resistor type and not to be used with Magneto’s. Can you get Iridium plugs that will run with a magneto?

I always found that 5 kilo ohm resistance made no difference to starting or running with a magneto.

My reason for asking is that I tried NGK Iridium plugs in my 62 gold flash (iron head) and after about 10 miles the bike began to miss fire and run badly at higher rev’s. Stopped changed back to BP6HS and she ran fine🥴

The iridium plugs I tried were BPR7HIX and seem to improve cold starts🤪 where as the BP6HS tends to be a little more difficult 🥴

BPRHIX is one grade colder than BP6HS, so it may foul under conditions where BP6HS would not foul.

On the other hand, plugs faulty from new, that stop working after a few miles, are not unknown.

In many cases, particularly if the magneto coil has been properly rewound, vacuum impregnated etc. using a resistor plug or plug cap might be OK (but unnecessary). However, a magneto coil has about 5000 ohms resistance in the windings due to the number of turns of very fine wire. If you attach a massive resistor (another 5000 ohms) onto the end of the HT wire - and don't forget that the HT wire is just an extension of the coil windings- you are making it more difficult for the pulse (spark) to find its way to the plug gap. The spark wants to find the quickest and easiest route to earth which should be across the plug gap. By putting a barrier (resistor) in the way of the spark you are encouraging the spark to find an alternative route to earth. Original Lucas magneto coils will, by now, have very weak insulation and the likelihood is that the spark will take the lazy route home which is by bridging the insulation in the coil and sparking onto the armature cheek. Modern rewound coils, assuming they have been wound by somebody who knows what they're doing, are less prone to this as the insulation is better quality. However, rewinding a magneto coils is a skilled job, and judging by some of the rewinds I see, I wouldn't want to stress those any more than I would want to stress an original Lucas coil. To be fair, the majority of rewinders know what they're doing or they wouldn't stay in business very long.

60

Lucas, Ignition, Charging, Electrical / Re: Iridium Spark Plugs

« Last post by Triton Thrasher on 28.03. 2025 10:45 »

I read in some Thread recently that Iridium Spark Plugs are resistor type and not to be used with Magneto’s. Can you get Iridium plugs that will run with a magneto?

I always found that 5 kilo ohm resistance made no difference to starting or running with a magneto.

My reason for asking is that I tried NGK Iridium plugs in my 62 gold flash (iron head) and after about 10 miles the bike began to miss fire and run badly at higher rev’s. Stopped changed back to BP6HS and she ran fine🥴

The iridium plugs I tried were BPR7HIX and seem to improve cold starts🤪 where as the BP6HS tends to be a little more difficult 🥴

BPRHIX is one grade colder than BP6HS, so it may foul under conditions where BP6HS would not foul.

On the other hand, plugs faulty from new, that stop working after a few miles, are not unknown.