Just wanted to throw this out there since I didn't find any info here, or over on vfrdiscusssion.com. I just got a new 1992 VFR750. It was only running on 3 cylinders when I got it, So I adjusted the valves. That didn't help. Then I bought new spark plugs from oreilys because they told me they had the new/equivalent variation of stock plugs (E3.38 using diamond fire technology) now, I didn't care which brand/how fancy the plugs were because I just wanted to see if the thing would run right before I invested any more time or money into the engine (I thought it had a rod knock and was on its last leg anyways. 74,000 miles on it). Anyways, upon opening the package of the e3 plugs I noticed you can't adjust gap. It's pre-set. So, I crossed my fingers threw them in, and started the bike. And it ran like shit. Popping and backfiring. So, I threw the sock plugs back in and it ran better, (although still on 3 cylinders. Carb cleaning took care of that. Now it runs good) Just thought I'd mention, e3 plugs did not work for me, in case anyone else was wondering.