LCGB Forums

So I want to run my rebuilt S2TV2175 engine 6 volts and points as I’m trying to keep the restoration as original as poss.
I’m at the end of my tether though I’ve rigged the engine up on a test bed so I can check the rectifier works and timing etc. I can’t get a spark at the plug though. Kept it Simple at the moment the green is connected to the coil and the lighting wire taped up. Good earth but I’m getting a spark across the body of the plug when I earth it and not the electrode? Got to be something stupid but I’m lost.
Any ideas?
Cheers steve

Are green and earth on HT coil correct way around.

I am a fan of points due to their reliability

Twelve volts can still be attained whilst retaining points, & a DC system with battery offers some extra margin of safety IMO in the event of engine failure.

I've gone back to Champion plugs not only to avoid counterfeit NGK's, but my experience is that the Champion is far less fussy or prone to failure. My preference is for a fine wire, but definitely non suppressed caps should be used with points ignitions.

Warkton Tornado No.1 wrote:I am a fan of points due to their reliability

Twelve volts can still be attained whilst retaining points, & a DC system with battery offers some extra margin of safety IMO in the event of engine failure.

I've gone back to Champion plugs not only to avoid counterfeit NGK's, but my experience is that the Champion is far less fussy or prone to failure. My preference is for a fine wire, but definitely non suppressed caps should be used with points ignitions.

“fine wire”?

Andyf wrote:
“fine wire”?

Yes. The N87 is equivalent to an N3 but with a fine wire centre electrode.

They are commonly used in two stroke engines for racing in the USA because of their availability, but also in light aircraft specifically because they have less tendency to foul or cause detonation.

(I look out for them on eBay as they are occasionally available @ a substantial reduction on list price)

sounds like the ceramic insulation in the plug has ruptured or the top cap is no longer connected through to the centre electrode at the business end

i.e the plug has been drop kicked off the back of the truck on delivery to the supplier you got it from

Plugs can be knacked due to poor treatment in transit

or the top cap needs to be done up NIce and tighty or removed depending on the plug wire end cap style you use

Replaced the old type plug cap with a new non-suppressor cap and it’s ok. Must have been tracking down the inside Of the cap.

BTW asked my local mc dealer for champion plugs and he doesn’t stock anymore. Asked him about NGK and he reckons the dodgy fakes are more at the top end of the market ie £50 - £60 apiece. He said forgers wouldn’t bother with the low end stuff. Also said NGK have pretty much taken the market as far as he was concerned. He’d love to be able to supply other alternatives but not viable. So ended up with NGK again.

Thanks for your help

NGK are ok in car use but i have found that once fouled they don't recover when cleaned as well as they used to. less of an issue with other brands. not sure what they did to the insulators/ceramic... potentially a problem with petrol these days

if i tune a carburetter equipped car especially with weber or dellorto (easy to be wildly over fueled initially, or have wrong heat range, when the motor is no longer standard) new plugs for tune then swap to a new set once all good.
which is fine if they are couple quid, purchased in retail multi packs. obviously i wouldn't if they were 70 quid a set, if that's the case I make use of a gunson colour tune first (its a handy thing....honest and easy to use) for idle mix and a lambda sensor set-up for mid and top end.

dave

PS champion went through a rough patch about 10 years ago, too many faulty out of the box. If you use 8 at a time, 2 or 3 sets of 8, with a dud in each quickly changes your mind.... quality control or poor handling before sale? dunno.... every batch had a "friday afternoon" lack of care Plug in it. confusing as hell on a multi cylinder multi carb motor, spend all afternoon gapping plugs chasing a misfire round and round.

Stevepshipley wrote:Replaced the old type plug cap with a new non-suppressor cap and it’s ok. Must have been tracking down the inside Of the cap.

BTW asked my local mc dealer for champion plugs and he doesn’t stock anymore. Asked him about NGK and he reckons the dodgy fakes are more at the top end of the market ie £50 - £60 apiece. He said forgers wouldn’t bother with the low end stuff. Also said NGK have pretty much taken the market as far as he was concerned. He’d love to be able to supply other alternatives but not viable. So ended up with NGK again.

Thanks for your help

In his racing days, Ray (Kemp) used to swear by Champion....

They still stock them (N3 & N4) which tells you something & you might find un-suppressed spark plugs there as well....

N3 & N4 plugs are non-suppressed.