S3A constantly whiskering plugs??

[perfectpete]

Hi there,

My recently rebuilt S3A is driving me crazy - one day she will run sweet as a nut and not miss a beat. Then, another day and she starts misfiring, so out with the relevant cylinder plug (it varies as to which cylinder!), and once cleaned up, she's running ok again!
I get roughly 30 or so miles of running before this happens - although it's not at the end of the run - it's the next day or so when the problem happens.
I have cleaned all electrical joints / earths throughout, and also replaced all points, condensers, coils and resent the gaps and timing.

I have also heard that Iridium plugs are good to stop the whiskering issue - anyone got experience of these?

Regards, Pete

[TF1]

Iridium plugs made my h1 and h2 misfire and foul plugs

[SAM]

Duff ngk?

[mraxl]

Some things to consider....
-plug gap
-carb tuning
-2T oil
-B8HS plugs
-Don't baby it... run to red line a few times when ever you're out

[SAM]

B8hs. Unless your racing!

[perfectpete]

Thanks all for the feedback!
Interesting - i have been running B9hs plugs since the engine rebuild (at the suggestion of the rebuilder), and plan to convert to standard B8hs after another 100 miles or so of running in - so let's hope this improves matters.
I am also going to get my carb's 'Tango'd' shortly, so i am sure this can do nothing but improve matters!

Regards, Pete

[Wolfie]

B9s or B8s should be fine, but where did you buy them?

[perfectpete]

Hi Wolfie

I bought them off the internet - surely an NGK plug is an NGK plug wherever it comes from - or is it??

[Wolfie]

Oh no definitely not.. the market was flooded with cheap chinky copies some years back, only buy them from your local bike shop.

I'll put money on that solving your problem..

[SAM]

Oh no definitely not.. the market was flooded with cheap chinky copies some years back, only buy them from your local bike shop.

I'll put money on that solving your problem..

Yep. They are everywhere!

[Nick64]

http://www.ngk-sparkplugs.jp/english/te ... index.html

[Barrie]

change your 2 strke oil

[SAM]

Ngk have big depot in hemel Hempstead! Might look by to see what they can do.

[Aardvark]

I use Green Spark plug company for my NGK's.

I also use B8s plugs.

Touch wood so far no problems in six years.

Regards

Aardvark

[perfectpete]

Thanks all for the replies - i am stunned anyone would even bother to copy spark plugs, but there's modern life for you!
Will pop over to my local bike shop as suggested and start again with genuine new ones!

Incidentally, i am using Motul Technosynthese 2 stroke oil as recommended to me - any comments / advice on best oils to use (got a feeling i might have just kicked open a hornet's nest here with this question, but oh well??!!)

Regards, Pete

[Wolfie]

Gosh you must like burning yer money...

Try Carlube from Morrisons..

I don't know that stuff personally but these old motors don't burn hot enough for some modern synthetic oils and everything gets gummed up.

You could do a search of the site for 'Two stroke oil' and see how many times that hornets nest has been kicked..

[SAM]

As Graham says. Synthetic not a good idea. Mineral oil just fine. I buy 20 litres at a time.

[Doctorpayday]

Gosh! how do you manage to close the seat down?

Doc

[SAM]

Gosh! how do you manage to close the seat down?

Doc

Problem it's a big container!

[Neil the Don]

Pretty sure your engine rebuilding would have suggested you run B8s while running in , then switch to B9s for full review riding.

And that Motul 1000 mineral oil is fine for that engine ?

[Mitsui Spy]

I have been using Chinese NGKs (£16 for 20) and Asda mineral oil £5/litre in my 400 for years. Since I put it back to CDI from points it now runs fine on the plugs it fouled when it was on points. It gets caned everywhere and doesn't foul plugs or seize up.

A fouled plug says more about the ignition system than the plug.

A seizure says more about the way the bike is set up than the 2-stroke oil.

[gotz]

I have been using Chinese NGKs (£16 for 20) and Asda mineral oil £5/litre in my 400 for years. Since I put it back to CDI from points it now runs fine on the plugs it fouled when it was on points. It gets caned everywhere and doesn't foul plugs or seize up.

A fouled plug says more about the ignition system than the plug.

A seizure says more about the way the bike is set up than the 2-stroke oil.

I totally support the above. Fouled up plugs can also be a result of riding habits....one of the many things my Dad taught me with a 2 stroke engine was ' to always work the throttle....don't always ride in the highest gear,.shift down now and then and let the motor rev ' .If my memory serves me right I only had 1 fouled spark plug and that was 1978.