Absolutely not. Because the cams may not sit still during your removal/replacement, the cams may jump a tooth. You have to guarantee that when your swap the tensioner out, that nothing moves. After getting the new tensioner in, you must adjust out the slack in the timing chain, then check the timing marks on both of the cams, then roll the crank around with a wrench and check the timing of the cams again and I say this because sometimes especially with the manual tensioner, you may not have taken up all of the slack in the timing chain. As you roll the crankshaft around, check the timing chain for looseness and adjust up as required. ( You'll understand what I'm talking about as your doing it) If you do something stupid like roll it around on the starter and one of the cams ( or both) are out of time, you'll bend a valve(s) and then you'll be pulling the head.
