How do you bump start a thumper?
Posted June 09, 2003 - 04:12 PM
Posted June 09, 2003 - 04:20 PM
Pull in the clutch and compression release. Let out the clutch and then comp. release. Wroom. A bit tricky but it works.
Posted June 09, 2003 - 04:28 PM
pulling the bike back in gear puts the piston right after tdc.this is how we start our push start only dirt trackers.
Posted June 09, 2003 - 05:35 PM
Posted June 09, 2003 - 05:42 PM
Hopefully I will never have to do this but I should know how at least.
I became quite adept at bump starting my 426, this saved my ass more than once in a race when I had brake-stalled my bike. I had a GYT-R thumb-lever compression release, and this made it even easier and more natural to just feather the lever the instant I stalled the bike (no clutch needed if you are already in motion). The motor pretty much always stops with the piston at TDC-compression, so you just need to let the piston get beyond that and allow it to come back around two strokes later on compression again w/ the compression "on." On one occasion I restarted my bike in some deep braking bumps, in second gear, barely moving, and preserved a tenth place finish (whoopee).
Anyway, if you need to bump a 426, do like was already advised. Second gear, clutch and decomp in, release clutch then decomp. If the rear tire drags just "slip" the decomp lever, allowing the motor to just get past TDC-compression, and hope it lights the next time around (just as you would if kickstarting it).
Hope this helps.
Posted June 10, 2003 - 02:57 AM
Posted June 11, 2003 - 04:50 AM
Posted June 11, 2003 - 07:39 AM
Mine will bump start without the decompression lever trick.
Hmmm. I doubt it would every time.
Using, or not using, whatever, the decomp lever will not hurt anything.
Posted June 11, 2003 - 08:55 AM
Posted June 11, 2003 - 10:46 AM
Posted June 11, 2003 - 01:37 PM
I just put it in 1st, pull in the clutch lever, push and get it going as fast as I can and then jump on and release the clutch. Going down hill works better. I'v had it stall before letting out the clutch to fast and not giving it enough throttle and i can pull the clutch in and let it out and it will start.
No fair, you have an automatic decompression mechanism.