by JimDirt » Tue Jan 23, 2018 10:03 am
Heat range is not all of the equation , the tip of the electrode has to do with performance and heat in the cylinder , the "standard" tip that the Champion has can cause Detonation , etc , so its not just heat range , the plugs the engine calls for are specifically designed for the application , where the Champion would be more for a V8 , etc , and not designed for a Performance V8 either , that is why i suggested replacement/repair , as i personally would not run the bike that way , its just hard on parts , remember these are performance engines , not a lawn mower engine , NGK and ND might make a closer plug to the original , in the size you need that has the correct electrode (pinpoint fine electrode) till you can do the repair/swap , you want to pay attention to Tip Protrusion , and measurements of that plug in comparison to the OEM plug , they really need to "look" the same , , but bottom line , either repair or replacement would be your best option in this situation .....
I would never run a plug not made for my engine , not saying you need to do what i say , since you have been running it as is for a while , just saying running it like it is , is not the best option available , you can get a used head on eBay if new head cost is a factor , and just bolt it on and be on your way (just swap your cam tower , and adjust the valves) , then you can either repair the old head or just run the used one for the season , then maybe do a valve job , new piston/rings , over the winter and have a fresh bike for next riding season ..............................
2020 CRF450R
2006 CRF450X
Weiser , Idaho