Re: Im going to run a NGK B5HS spark plug....
The NGK 5 is a hotter plug than a 6... I run a 5 in the winter & a 6 in the summer.
To answer your question, a hot or cold plug will not make your engine run any hotter or colder, but the amount of heat from your engine can make the plug run too hot or cold; (& a plug thats running too hot or too cold can make your engine run like s**t!!!)
A plug thats too cold isn't hot enough to burn off all the gas & oil that builds up on it & can foul out; A plug thats running too hot can get glowing red hot spots & cause pre-ignition!!
Thats why when my engine starts running hotter in the summer, I switch to a slightly colder plug (& visa-versa).
Last edited by Venice Motor Bikes; 11-19-2009 at 12:13 PM.