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421 b settings
what is a good standard setting for a 421b motor? ive been chasing this motor all over the place
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RE: 421 b settings
If you're running a high end engine like the 421, you should know that every engine will tune differently, there's no magic setting.
If you're totaly lost go back o the stock settings and work from there. many people complain about having trouble setting engines like the 421 or Rb these engines do not have very good low end you have to get a late engaging clutch and a low to mid range pipe. Good luck, i hope this helped a bit. |
RE: 421 b settings
Buy a temp. gauge (if you don't have one) and. . .
1.) Reset needles to stock settings (you may need to lean slightly over break in settings to keep car running) 2.) Warm car up until chassis gets hot, making sure temps never exceed 250 3.) Lean HSN to keep temps between 220-250 making sure smoke is visible between low to mid RPMs 4.) Lean LSN until pinching fuel line near carb causes engine to stall between 3-5 seconds 5.) Check to make sure low end changes haven't made motor exceed 250, if they have richen HSN 6.) Adjust idle as high as you can without car stalling. 7.) Re-check above any time outside weather changes significantly, or at the beginning of a day of driving If you don't know the stock engine settings, try setting your LSN and HSN to 3 turns out. If you have a three needle carb, set the MSN (I forget the actual name) to flush. This needle can be tricky though, as the stock settings are often calibrated from the factory, and generally shouldn't be changed until you have mastered engine tuning (maybe not even then). |
RE: 421 b settings
ORIGINAL: zwilldog what is a good standard setting for a 421b motor? ive been chasing this motor all over the place |
RE: 421 b settings
by asking this question I can already see you bought the WRONG mill......if you're not a tuning god then get ready for a $400 paperweight......that mill is very timing sensitive....what fuel are you running for 1?, what shims are you using? what plug and has the engine been broken in yet?......
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RE: 421 b settings
ORIGINAL: kx250ryder Buy a temp. gauge (if you don't have one) and. . . 1.) Reset needles to stock settings (you may need to lean slightly over break in settings to keep car running) 2.) Warm car up until chassis gets hot, making sure temps never exceed 250 3.) Lean HSN to keep temps between 220-250 making sure smoke is visible between low to mid RPMs 4.) Lean LSN until pinching fuel line near carb causes engine to stall between 3-5 seconds 5.) Check to make sure low end changes haven't made motor exceed 250, if they have richen HSN 6.) Adjust idle as high as you can without car stalling. 7.) Re-check above any time outside weather changes significantly, or at the beginning of a day of driving If you don't know the stock engine settings, try setting your LSN and HSN to 3 turns out. If you have a three needle carb, set the MSN (I forget the actual name) to flush. This needle can be tricky though, as the stock settings are often calibrated from the factory, and generally shouldn't be changed until you have mastered engine tuning (maybe not even then). Are you sure about #6 ??? |
RE: 421 b settings
Oops, typo should actually be:
6.) Adjust the idle as high as you can without the clutch engaging (making the car move). |
RE: 421 b settings
ORIGINAL: kx250ryder Oops, typo should actually be: 6.) Adjust the idle as high as you can without the clutch engaging (making the car move). I always try to set it as low as possible - but I am more than willing to learn something new. |
RE: 421 b settings
i ACTUALLY AIM FOR THE MIDDLE OF WHAT YOU 2 DO. But if the car will Idle without the wheels spining and the brakes off, then that is it.
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RE: 421 b settings
Having the highest possible idle puts you closer to the power band when you go to accelerate. This means less time between when you hit the throttle and when the clutch engages. Since the engine is revving higher, it is less likely to stall as well, compared to an engine that is idled low enough to barely stay running. This does mean that you will burn through your available fuel faster when you are upside down though.
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RE: 421 b settings
Yes, but this is an area of personal preference. Plus as I have a V-Spec and P7-R the power bands are right at the bottom and having the low idle also aids cooling, longer run times are possible and should you be upside down for some time (DAMN THOSE MARSHALLS) you will remian running longer as mentioned before.
B U T as your clutch heats up and the springs lose the tension, the lower idle will aid against engine cut outs from braking with the clutch engaged. |
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