If the mag side of my crank is out 5 thou on a dial indicator after top dead center would that be enough to make that cyl run like crap?
you mean it has .005" run out.. right??
to check phase you need to measure in between where each cylinder is at tdc to make sure it is 120 degrees. If you suspect a phase problem you can check it quickly by removing all 3 plugs, then make a mark on the engine case right above the clutch at 12 o clcock. Then using a long handle screwdriver insert till it touch piston, rotate the engine via clutch till screwdriver is at tdc, mark the clutch in line with your mark on case. Repeat this for all 3 cylinders. when your done take a cloth measuring tape and measure around the clutch to your marks, should all 3 be the same , if not the crank is twisted or out of phase.
to check phase you need to measure in between where each cylinder is at tdc to make sure it is 120 degrees. If you suspect a phase problem you can check it quickly by removing all 3 plugs, then make a mark on the engine case right above the clutch at 12 o clcock. Then using a long handle screwdriver insert till it touch piston, rotate the engine via clutch till screwdriver is at tdc, mark the clutch in line with your mark on case. Repeat this for all 3 cylinders. when your done take a cloth measuring tape and measure around the clutch to your marks, should all 3 be the same , if not the crank is twisted or out of phase.
marty f
New member
MR.VIPER700,your inbox is full..looking to get my power valves fixed(pulled thru)2000 srx700
82f100swb
New member
What he is trying to say is when I marked tdc with the dial indicator, the mag cyl is almost 3/16" out. At the position where tdc should be, it is already .005 from tdc on its way back down.
Sent from my SM-G900W8 using Tapatalk
Sent from my SM-G900W8 using Tapatalk
So is 5 degrees enough past top dead center, on the mag cyl to make it run like poop between 2000-4000rpm only?
Out of phase will typically show signs of rough idle, weak on power at any rpm range and a loss of top end speed/power. I wouldnt think it would show at your specific rpm range.
I have never ran a degree wheel as a confirmation as most times the phazing shows up readily with the dial indicator.
as stated if the crank is out of phase they run bad at all rpm, because the piston is not timed to the port openings and can not choose rpm its off from beginning to end.
Like I said my problem starts just off idle and is all over at clutch engagment. Talked to one of my racing buddies, and he had gone directly to Yamaha for an all new $1800 srx 700 crank and one of the cyls was out 8 Thou. And he said if it ran great at 8 thou out then 5 shouldnt affect anything. I tend to agree however I am no closer to figuring this pain in the a** out!!!!!!!
Can the timing on these engines be adjustable? Thats my last hope otherwise it will go up for sale.
Can the timing on these engines be adjustable? Thats my last hope otherwise it will go up for sale.