Phelps Posted May 12, 2010 Report Share Posted May 12, 2010 for you alky guru's what do you run "TOTAL TIMING"? i was told 30 degree's and i just want to double check. i built a bike for a friend 421 cub bike 5 1/2 years ago and it was always low on power and jetting was never gotten right. pulled the cover yesterday and realized the plate was still on 0 from when we broke it in on gas. we also have a dynatek set on 25 degree's total. Quote Link to comment Share on other sites More sharing options...
Phelps Posted May 12, 2010 Author Report Share Posted May 12, 2010 ????? Quote Link to comment Share on other sites More sharing options...
Phelps Posted May 12, 2010 Author Report Share Posted May 12, 2010 ?????? Quote Link to comment Share on other sites More sharing options...
RadarRacing Posted May 12, 2010 Report Share Posted May 12, 2010 A stock flywheel/ plate setting of "0" is still firing about 17 degrees BTDC and usually we run 7 to 12 more than that. Each motor likes something different. Hope that helps. Radar Quote Link to comment Share on other sites More sharing options...
Phelps Posted May 12, 2010 Author Report Share Posted May 12, 2010 so 25-30 "total timing" ok thank you very much! i set it at 28 total yesterday, but i didn't want to run it wot until i double checked. just from the new found response of the engine i knew i had to be very close. Quote Link to comment Share on other sites More sharing options...
RadarRacing Posted May 12, 2010 Report Share Posted May 12, 2010 You are on the high side of what most people run. 17+ 7 is 24 and most run there up to 17+9 which is 26. I'd try 7 over stock to start with( 24 ). 28 degrees is 11 over normal and a lot of motors will burn holes in pistons or burn up with that much. If you add timing remember to add a bunch of fuel. If I was goin to LS this weekend with ya'll I'd help ya. Radar Quote Link to comment Share on other sites More sharing options...
Phelps Posted May 12, 2010 Author Report Share Posted May 12, 2010 You are on the high side of what most people run. 17+ 7 is 24 and most run there up to 17+9 which is 26. I'd try 7 over stock to start with( 24 ). 28 degrees is 11 over normal and a lot of motors will burn holes in pistons or burn up with that much. If you add timing remember to add a bunch of fuel. If I was goin to LS this weekend with ya'll I'd help ya. Radar the fixed plate is at +5 and the dynatek graph shows almost a peak of 23 curving down with rpm. do you still think that is too much? it's easier to drop the dynatek curve rather than take the side cover off, so i may drop it one setting. i got my initial info from a guy that worked for K&N and set bikes up for them. now i am not saying he is the one is right on the 30degree's, but he also said i shouldn't be running anything less than 210lbs of compression. i just don't want to take 1 guys info and burn a engine down so i appreciate all the help from you. Quote Link to comment Share on other sites More sharing options...
shanYE west Posted May 12, 2010 Report Share Posted May 12, 2010 the fixed plate is at +5 and the dynatek graph shows almost a peak of 23 curving down with rpm. do you still think that is too much? it's easier to drop the dynatek curve rather than take the side cover off, so i may drop it one setting. i got my initial info from a guy that worked for K&N and set bikes up for them. now i am not saying he is the one is right on the 30degree's, but he also said i shouldn't be running anything less than 210lbs of compression. i just don't want to take 1 guys info and burn a engine down so i appreciate all the help from you. One key part that is being left out is the dome design.... It plays a huge roll on where the sweet spot will be for setup. Quote Link to comment Share on other sites More sharing options...
Phelps Posted May 12, 2010 Author Report Share Posted May 12, 2010 One key part that is being left out is the dome design.... It plays a huge roll on where the sweet spot will be for setup. i honestly couldn't tell you, because it's been so long. to the best of my knowledge but factory heads ere cut per Nmotions spec's. of coarse it was for gas though. the diameter was taken out to 68mm, it was milled .40 and the angle was changed to 11 degree's. <--- the best i can remember. (they didn't offer custom domes for a cub motor in 05 that i know of) i have no idea what cc it would come out to i just know it is not your typical cool head dome shape. more of a gradual dish than just staying flat then dropping in. Quote Link to comment Share on other sites More sharing options...
AKheathen Posted May 12, 2010 Report Share Posted May 12, 2010 actually, 08 on the plate is 17*only up to 2k, then it jumps to total 22* and tapers down to 9*....so, that would be a 29*total @ +7, and 34* total @ +12........that is actually what you are setting it at, just to clarify what it would conver to when using the dyna and plate Quote Link to comment Share on other sites More sharing options...
Phelps Posted May 12, 2010 Author Report Share Posted May 12, 2010 actually, 08 on the plate is 17*only up to 2k, then it jumps to total 22* and tapers down to 9*....so, that would be a 29*total @ +7, and 34* total @ +12........that is actually what you are setting it at, just to clarify what it would conver to when using the dyna and plate i am just meaning peak total time at any point in the rpm range. i understand there is a curve, but when drag racing you are never really below 5-6k rpms. i just don't want the bike to be over 28-30 any any one time to be on the safe side. as it was before it was to slow on timing due to the dyna not going but to 23 total per there graph. i want 28-30 total. Quote Link to comment Share on other sites More sharing options...
shanYE west Posted May 12, 2010 Report Share Posted May 12, 2010 i am just meaning peak total time at any point in the rpm range. i understand there is a curve, but when drag racing you are never really below 5-6k rpms. i just don't want the bike to be over 28-30 any any one time to be on the safe side. as it was before it was to slow on timing due to the dyna not going but to 23 total per there graph. i want 28-30 total. I'd off the dyna and go with a stock CDI Quote Link to comment Share on other sites More sharing options...
Phelps Posted May 12, 2010 Author Report Share Posted May 12, 2010 I'd off the dyna and go with a stock CDI how about just setting the cdi to stock position? then what going +10 on the plate? Quote Link to comment Share on other sites More sharing options...
firebanshee Posted May 12, 2010 Report Share Posted May 12, 2010 how about just setting the cdi to stock position? then what going +10 on the plate? My 421 cub liked +10 with stock ignition. Quote Link to comment Share on other sites More sharing options...
VegasJeff Posted May 12, 2010 Report Share Posted May 12, 2010 how about just setting the cdi to stock position? then what going +10 on the plate? thats the combo I run, +10 on the plate and stock curve on the dyna box. Quote Link to comment Share on other sites More sharing options...
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