tyler440
New member
hey guys i have a mikuni slide rule at home, but im real curious to know right now. if any of you have a slide rule in front of you please help.
im planning on taking my 84 vmax 540 oval racing on saturday. Today's forecast shows temps of 50*F for that day. Tho im not sure our snow will last the week, what size mains and i needing for a 20+ temp change? they are mikuni vm38's if that matters.
Right now it is running good with 290 mains at 30*F. I imagine i will drop the needles a position or two with the warmer temps also. Is it worth the hassle to mess with the pilots for a 3 lap (1.5mile) blast.
I have egt gauges and have seen temps over 1200 with no problems (stock jetting) the other day when i tested they were showing low 1100's. so im thinking it was a little fat then. but the plugs were nearly white. I trail rode at mid throttle for a couple of miles and they turned nice brown. A blast around the fields and they turned back to nearly white.
I would rather be rich than lean and burn down. we only race twice a year, so we aren't that serious. but it is fun to act like a professional outfit in front of the boofers that i'm racing against.
When it comes to the class i really want to win 5-600cc (new sleds) i would really like to show a f6 or some other tuff guy that the 1984 stuff still has it.
side note: the first time this track had races i was swerving around a hood in the first turn of hot laps. the sled it came from was still going, he just lost his hood hahaha
im planning on taking my 84 vmax 540 oval racing on saturday. Today's forecast shows temps of 50*F for that day. Tho im not sure our snow will last the week, what size mains and i needing for a 20+ temp change? they are mikuni vm38's if that matters.
Right now it is running good with 290 mains at 30*F. I imagine i will drop the needles a position or two with the warmer temps also. Is it worth the hassle to mess with the pilots for a 3 lap (1.5mile) blast.
I have egt gauges and have seen temps over 1200 with no problems (stock jetting) the other day when i tested they were showing low 1100's. so im thinking it was a little fat then. but the plugs were nearly white. I trail rode at mid throttle for a couple of miles and they turned nice brown. A blast around the fields and they turned back to nearly white.
I would rather be rich than lean and burn down. we only race twice a year, so we aren't that serious. but it is fun to act like a professional outfit in front of the boofers that i'm racing against.
When it comes to the class i really want to win 5-600cc (new sleds) i would really like to show a f6 or some other tuff guy that the 1984 stuff still has it.
side note: the first time this track had races i was swerving around a hood in the first turn of hot laps. the sled it came from was still going, he just lost his hood hahaha
A couple of bucks
VIP Member
For every 20 degrees, 1 jet size. So in your case, 1 jet size would be safe. It's gonna be on the bubble(as far a temp goes) weather you bump in down 2 sizes.tyler440 said:
tyler440
New member
alright cool. i actually never did get out the slide rule for this because im banking on the snow not lasting. but thank you for replying. ill know for when it does happen, or im we get it on grass someday