after trying a variety of after run procedures & oil combinations over the years, here is what is working the best for me. i don't flush with wd-40 or any oil in the traditional manner. no matter what i did, i had bearing issues on occasion. now i take straight methanol & byron's 95% synthetic/5% castor, mixed at 33% oil. i put that in a separate tank ( i use a 6 oz. sullivan), & after running, i hook up the lines from my afterrun tank to the pipe & carb & run the engine on the bench for a few minutes. you will need to richen it up a good bit to keep temps down, as that much oil creates more heat. you will also prolly need to keep an igniter on it to keep the plug lit. run at a fast idle, & keep an eye on temp, fatten as needed to control temps. my thoughts are that by running the engine, you build heat & rpm to completely remove any moisture & nitro. i feel that running gets the oil more places than just spinning with a starter, plus more run time & heat also works it in more places than a starter would. after i shut it down, i open the carb, pull the plug, put the piston down to bdc, & let it cool. all the methanol will evaporate almost immediately, leaving just oil & plenty of it. i have been doing this for the past 2 seasons, & have eliminated any bearing issues so far...... another plus is you have an oil that normally is used in fuel, so no need to blow it out before the next fire up, & also no chance of some additive attacking orings or seals. some folks will say "but i loose my needle setting". get a boris meter, or close it down, counting the turns to when it seats. reset the needle to the setting you recorded last, & run it. works for me, mixed up 1 quart beginning of the season, still have close to 1/2 left, so it doesn't take much. for me, it turns out to be cheaper than wd-40 & after run oil brew for a season. that is for 3 .21's at 5 races, 4 .21's at 2 more, plus teasting. your comsumption may vary ..........