A common myth.... Too lean will melt your engine' date=' too rich will wash bores/rings and contaminate oil causing bearing failure - which is better? 9 AFR will cause black smoke from the exhaust and wash the piston rings way. I wouldn't drive it anywhere like that, sounds like you have injectors twice the standard size. [/quote'] Very interesting! I wouldnt be surprised if that is what happened to my 1st vr all those years ago! Been told running it rich was ok for 150 miles to get it mapped!! No wonder i got the issues i did! The black rear window was the least of my probs lol!