Originally Posted by
Ted Su(TW)
I need some help on understanding how to choosing the right plug, instead of being told what plug to use.
For e.g, my engine is a Keep on 9 XLS, temperature is around 25 to 35 degree celcius. 25% nitro. How should I choose?
1. Hotter plugs for colder days or the other way around?
2. Hotter plugs burn oil more efficiently than cold plugs? If my engine is running rich, will it become relatively leaner i I switch to a hotter plug? And what will be the consequences?
3. For this engine, I was told to use the C8TGC and it's running fine. What will happen if I switch to C7TGH?
Thank you for your time.
Ted
The best plug for that engine in the ambient temps you have and 25% nitro is C8TGFB. Just run that plug you don't need to consider anything else unless you go down to 16% nitro and the temperature falls below 20 degrees then you could consider a slightly warmer C7TGFB plug. Don't get overly concerned over plug choice as you've only got 2 options really for onroad.21. My advise is run the C8TGFB 99% of the time and if you get a really cold day you could goto the 7.
On.12 size engines we run C6TGFB almost exclusively unless it's really hot outside or you are running 25% fuel then we consider going to a C7TGFB.
In a nutshell the higher the number the colder the plug. Higher the nitro content the colder the plug. The hotter the ambient temperature the colder the plug. The opposite in all cases the hotter the plug.
My advise is stick to the 8 and concentrate on tuning the engine correctly and you'll be fine.
By the way the 'C' plugs are for offroad engines and shouldn't be used onroad. The engine will run but it isn't ideal. You should be running either the old C8TGH or the new (and much better/stronger) C8TGFB.
http://www.novarossi.it/2012/index.p...s/on-road.html
http://www.novarossi.it/2012/index.p.../off-road.html