Join Date: Feb 2009
Location: High Ridge, outside St. Louis, MO
Starting an engine after a rebuild / other rebuild Qs
This winter I rebuilt the top end on my 2007 YFZ. it got a new 12.75:1 CP piston, new valve seats, and porting, along with various ither internals (timing chain, clearances set, new stator cover internals) but anywawys, i was wondering if there is any sort of special process when starting up an engine right after a rebuild. I'm in college, so i really took my time, which would lead me to believe that 99% of the oil is either out of the motor, or chillin' out at the bottom. I did use a 50/50 mix of synthetic oil and WD-40 as assembly lube on the wrist pin and other important things, so im not worried about that. Im mostly worried about the cams and other things that need lubrication immediately but wont have it.
another question, see my mods in my sig. before a HC piston, and porting, i was at 48/168/2.5 out. what jets do you suggest i pick up to tune with? i was thinking a 45 48 and 50, a 165, 168, 170, 172, 175, and i also picked up an adjust-on-the-fly fuel screw so i can fine tune that. My needle is stock. should i get the NCVQ one? which clip do you think?
yet another question. Right now, i have a bottom end with cylinder, a head off the engine, and a bare frame in my basement. which is the best way to get the head back on? I was considering putting the engine in the frame with no head so that i could get sufficient torque on the head bolts.... anyone who has done this before please chime in. this is my first time rebuilding the YFZ.
feel free to ask any questions of me. im sure i left something important out.
THANKS FOR THE HELP!
2007 YFZ450 Red/Gray - DMC Afterburner Comp full system - Pro Design Pro Flow intake and air filter - CP 12.75:1 piston - port work by Outlaw Innovations - Stage 2 HotCams - EHS Racing airbox lid - AC racing blackline nerfs - TAG metals black bumper - bent accelerator pump spring - Adjustable Fuel screw - Maxxis RAZRs all around - 15/38 gears