Weak spark

[Tim]

Is the top of your carby stained with evaporated fuel?

Tim

[Doug G]

Is the top of your carby stained with evaporated fuel?

Tim

Yes.

[59Prototype]

Earlier in this thread there was talk of hotter and colder plugs and NGK and Champion were mentioned.

You might need to check this out but if my memory serves me correctly the numbering system used by the two companies is the opposite way round! The numbers run from 1 to 12 and the nearer you get to 1 with the NGK plug the hotter the plug. With Champion the nearer you get to 12 the hotter the plug! 5s and 6s in the NGK range are normally considered good all round plugs.

This information all came about as a result of me investigating the correct plugs to use in a 1934 RR that I am lucky enough to own (no, I'm not rich, the car is useful in earning me a bob or two doing weddings!). The original plugs were 18mm as opposed to the now more usual 14mm. Not only are the 18mm plugs more difficult to come by they are more expensive. What I wanted to do was fit a screw in adaptor to allow a 14mm plug to sit in an 18mm hole. Then I had a much wider choice of plugs to fit. Not only that, I could fit plugs with a longer reach assuming that they were not smashed to bits as the piston came up! I think it is a 5 rated NGK that I used. To be honest off the top of my head I can't remember exactly which plug it was but certainly a popular NGK one. The car starts well runs well and has a higher mpg. It was doing around 12mpg, now it's closer to 14. Yes that 14 miles per gallon!! The exercise has been worth it. Even though I had to buy the adaptors the cost of a 14mm plug and an adaptor was far less than just buying the 18mm plug. It's not really relevant to Mokes but thought you would be interested to know!

Graham

[Tim]

Hi Graham, I think you're right, the champions count down as they get hotter whereas the NGKs count up, so a champion N7Y is hotter than an N9Y , but a n NGK BP6ES is cooler than a BP8ES.

Doug, why not swap your fuel pump over and see what happens?

Tim

[59Prototype]

Hi Tim. Well I think it's actually the other way round in that NGKs get hotter as they run towards 1 and Champions get hotter as they run towards 12. So a champion N7Y is colder than an N9Y , but a n NGK BP6ES is hotter than a BP8ES. For the life of me you would have thought the two companies would have worked the same way in running from 1 to 12!

Here's an NGK chart that gives a complete run down of what all the numbers and letters mean :

http://www.ngk.de/fileadmin/Dokumente/E ... ode_en.pdf

Incidentally the other thing I recently learnt is that if you are running electronic ignition in place of the original points system you can widen the plug gap. With a CSI electronic ignition system on my Cooper S I have now gone from a 25 thou gap to 40 thou and the car starts and runs extremely well. The CSI Lucas look-a-like distributor was expensive but I consider well worth the money spent. Coupled with an Aldon Flamethrower coil the car is now running better than at any time since I bought it back in 1971.

Graham

[Tim]

Ooops, I should have known that. Its been a while since I needed to fiddle with them.

That chart is quite good, I wondered what all the different codes meant.

Tim

[Doug G]

Hi Graham, I think you're right, the champions count down as they get hotter whereas the NGKs count up, so a champion N7Y is hotter than an N9Y , but a n NGK BP6ES is cooler than a BP8ES.

Doug, why not swap your fuel pump over and see what happens?

Tim

Yes that his the obvious thing to do.

I'll try it.