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1980 xs650 special, just bought it. p.o. installed mikes pma unit and ignition set up. i want to check intake and exhaust valve lash but there are no marks on this new rotor. anybody know how to get around this? thanks
If it is not rephased, it is simple. Both pistons are at TDC at the same time. You want to adjust the side that has just completed the compression stroke. Just look for the intake valve starting to open and the exhaust valve starting to close on the other cylinder. Then rotate 360 degrees, anddo the other one.
Finding TDC for valve setting is no big deal. Even if you're just very close, it will be OK. But, what are you going to do, pray tell, if you ever need to check the timing? That's not set at TDC but rather something like 15° BTDC. You'll need to make proper timing marks for that. I really don't understand this but it seems to happen all the time - guys install PMA's and don't make new timing marks. It's crazy. It seems all the clowns have left the circus and are now running around loose, buying 650's and installing PMA's on them with no timing marks, lol.
Roll the engine over until you see one exhaust valve go all the way down(maximum lift), now adjust the opposite exhaust valve(it will be closed, on the base circle of the lobe). Now turn the engine again until that valve is all the way down and adjust the other exhaust valve. Now repeat the process on the intake side.
That's how us old Triumph riders did it, "we don't need no stinking timing marks".
what are you going to do, pray tell, if you ever need to check the timing? That's not set at TDC but rather something like 15° BTDC. You'll need to make proper timing marks for that. I really don't understand this but it seems to happen all the time - guys install PMA's and don't make new timing marks. It's crazy. It seems all the clowns have left the circus and are now running around loose, buying 650's and installing PMA's on them with no timing marks, lol.
Roll the engine over until you see one exhaust valve go all the way down(maximum lift), now adjust the opposite exhaust valve(it will be closed, on the base circle of the lobe). Now turn the engine again until that valve is all the way down and adjust the other exhaust valve. Now repeat the process on the intake side.
That's how us old Triumph riders did it, "we don't need no stinking timing marks".
If it is not rephased, it is simple. Both pistons are at TDC at the same time. You want to adjust the side that has just completed the compression stroke. Just look for the intake valve starting to open and the exhaust valve starting to close on the other cylinder. Then rotate 360 degrees, anddo the other one.
If it is not rephased, it is simple. Both pistons are at TDC at the same time. You want to adjust the side that has just completed the compression stroke. Just look for the intake valve starting to open and the exhaust valve starting to close on the other cylinder. Then rotate 360 degrees, anddo the other one.