A spark plug question

[Robby]

This is one one of my cars, but the principal is the same.

The car in question is a 1988ish BMW 320i - electronic igniton, but with a distributor of some kind on the end of the camshaft - still a contact one.

Right then, its not starting. Turning over fine, sometimes feeling like it wants to catch, but not really, apart from the occasional splutter on a cylinder or two.
The dizzy cap and rotor arm were horrible, so I replaced them. Still not starting, so I whipped out the plugs.

Now these look horrible, but laying them along the rocker cover with the HT lead on they still spark ok, big fat blue sparks. The problem being that on most of them the spark is coming from the insulation up to the arm, not the electrode up to the arm. The insulation is knackered.



So, after that little book, the question is simple. Can a plug spark healthily out in the open air, but not spark at all inside the very different conditions of the combustion chamber if its a bit knackered?

Trying to sell the car, so trying to avoid spending any more money on it.

[stinkwheel]

[Retro-Man]

Agree

Plugs are fucked.

The distributor thing is fairly classic of the 320 though.

Cheers
Retro
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https://domharnessphotography.webs.com

[binge]

Get a new set of plugs...

I agree that NGK are shit!

I bought an NGK-R Plug the other day and it didnt work, it was a duff plug.

<|BiNgE|>

[tatters]

denso plugs are widely sold on ebay, never had any troble with them, on another subject did you know that NGK have stated that there plugs are not ment to be used on two strokes
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Past:NRG50,AF1125(x2),NSR125RR,ZZR250,CX500,VFR400,KR1S,ZZR600(x2),CB400N,YZF1000(x2),KH125,Z200,FX400R,CBR954RR(x2)GPZ500S,GT550,VFR750F(x2),RD350N,XR650R,CBR600F,CB250,KDX250,YZF750R,CRM250,400EXC,KLR650,TTR600RE,DR350S,R100GSPD,RGV250,VMAX1200,DL650,KZ750 Present:G650XC,C12,CRF450X,1190ADV

[binge]

Thats strange, because when you buy a brand new speedfight they come with NGK plugs in. Also whe I got mine serviced they changed the plug and replaced it with a NGK-R plug!

hmm, So whats the best plug for a 2T?

<|Binge|>

[tatters]

bosh/denso Iridium should not oil up as bad as standard, or splitfire plugs (should last longer with two eletrobes). NGK are fine its just that they were never inteded for two strokes. stay away from champion plugs now they are crap
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Past:NRG50,AF1125(x2),NSR125RR,ZZR250,CX500,VFR400,KR1S,ZZR600(x2),CB400N,YZF1000(x2),KH125,Z200,FX400R,CBR954RR(x2)GPZ500S,GT550,VFR750F(x2),RD350N,XR650R,CBR600F,CB250,KDX250,YZF750R,CRM250,400EXC,KLR650,TTR600RE,DR350S,R100GSPD,RGV250,VMAX1200,DL650,KZ750 Present:G650XC,C12,CRF450X,1190ADV

[pipnet11]

[Kickstart]

Hi

Sounds like your plugs are really knackered.

Had problems with Scottys NSR. It seemed to be sparking fine, until I realised that it was actually sparking between the outer electrode and the engine it was (almost) earthed against.

NGK plugs used to have a very good reputation, but I have heard from loads of people that they have gone greatly down hill over the past decade. Not sure about them saying they are not suitable for 2 strokes but that seems strange when they sell the B10EG (and the like) which are pretty much only used by 2 strokes.

Think Champion stuff has got far better over the past decade.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Fortuna]

Get some Denso grooved type or multi tip plugs. On my machine it's worth 4bhp to have better plugs.
If you get good ones and set them correctly you really can tell the difference.

[Robby]

Replaced all the plugs. Still no life.

However, its smoking out of the oil filler cap when you crank it, and it was very tappety when it was running, so I'm thinking a combination of valve clearances and valve stem oil seals.


Bollocks to fixing it, I want the space back. Its on ebay as is.

[Fortuna]

[Dam_buster]

so what are the best Spark plugs for 2 strokes?


JIM
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Yamaha R6 5EB, BMW 328i Touring, BMW 328i Coupe

[Fortuna]