Join Date: Feb 2020
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2015 ST3 R CCT install
I'm about to replace the hydraulic cam chain tensioner on a high mileage 2015 ST3 R. I have the workshop manual (see clip below). The manual says that when installing a new tensioner "do not release the plunger" before install. It goes on to say to remove the wedge and the pin, rotate the engine 1/4 turn anti-clockwise, then rotate two full revolutions clockwise. This apparently engages the plunger on the hydraulic tensioner.
However, the manual also says in bold that the tensioner will be empty of oil on start up and that the blade/chain may be noisy for the first 5 seconds or so until the plunger feels oil pressure.
Here is my concern, there is a probability that the chain is already stretched. What is there to keep the chain from jumping a tooth while I hand rotate the engine with the tensioner not yet engaged? Also, assuming the hand rotation sequence releases the retaining clip and the tensioner goes under some spring tension, isn't there a chance of the chain jumping time in the 5 or so seconds it takes to build up oil pressure in the tensioner?
I would be less concerned if I were taking out the cams and installing new chain and blades but I was thinking of just changing the tensioner and tension blade first. If the chain is stretched on this 70K mile bike there seems to be a good chance that I could slip a tooth before the new tensioner self adjusts. Does anyone have any experience with this?
Last edited by JB Brock; 02-24-20 at 12:33.