I think the reason they say that is because the OEM is a dead end. It uses the oil pressure to push the chain tight. Once the chain is tensioned no more oil goes anywhere. When you install the manual tensioner that oil passage is no longer blocked allowing oil pressure to leak back to the pan. How much pressure is release don't know, how much oil can get by the threads of the manual tensioner?

APE MANUAL CAM CHAIN TENSIONER INSTALLATION INSTRUCTIONS
"IMPORTANT: WHEN REPLACING ANY HYDRAULIC OEM TENSIONER WITH A MANUAL TENSIONER, IT IS IMPORTANT TO MAKE SURE THAT THE OIL PASSAGE THAT SUPPLIED THE OEM TENSIONER IS BLOCKED OFF. FAILURE TO DO SO COULD RESULT IN A LOW OIL PRESSURE SITUATION".

Looking back at the OEM tensioner removal tutorial I made, I see the oil hole in the tensioner. I don't recall a single thing in the installation instructions for the APE referring to blocking it off. I don't see how the APE O-ring or any part of it plugs the hole that would feed the stock tensioner. All the oil that comes out of there runs straight back to the pan. I haven't had any trouble. I now have an oil pressure gauge with sensor installed in an adapter with the stock oil pressure sensor. My gauge goes up to 90 psi at about 4000 rpm and stays there all the way to redline. The oil pressure relief valve is opening at 4000 rpm. No low oil pressure with my APE tensioner. No measures taken to block the oil passage unless the APE automatically does that because of its shape or something.

* Last updated by: Rook on 4/9/2019 @ 6:35 AM *

Hello Rook, David,

Below I have pasted my email and the response from APE.

I have seen some videos on YouTube of other bikes and found that some bikes have an external oil passage to the original CCT and it gets blocked off differently. When you bolt the tensioner to the engine, the shape of the tensioner actually covers the hole and those tensioners are installed with a flat gasket when bolted on. The ZX14 is different and has an internal oil passageway so the body of the APE tensioner must have some kind of blocking properties. May not be a perfect oil blocking off but must be similar to the original tensioner thus no additional modification is necessary.

I have now installed my APE tensioner and am very happy with the result. No more rattle on start up and the engine actually sounds better at all RPM. I have had this bike since it was new and it sounds great again. Rook, I used your post as a guide for the tension and it was spot on. Kudos to you for this post and helping us take all of the guess work out of the job.

______________________________________________________________________________________________________________________
SENT EMAIL TO APE:
I have just placed an order for the APE KTZX14 Manual Cam Chain Tensioner.

I was hoping you could help me regarding my concern with replacing the stock tensioner with the APE manual tensioner. I am concerned regarding the oil passageway and if any other modifications need to be done. I am assuming that these units are being used on race engines then there should be no issue but I am wondering if the folks that are racing have done any additional modifications to the oil port that was supplying oil pressure to the OEM unit.

Thank you for your help.

REPLY FROM APE:
In most cases the body opf the tensioner blocks the oil feed. However, if it doesn't, then some tap it and insert a set screw of epoxy it

Jay / Tech

LOL How are you supposed to know if the APE is blocking the oil feed? If it isn't how the heck do you get a tap in there to cut threads for a set screw?

I wouldn't bother. Plugging the hole could cause problems and solve nothing. I've never heard of an APE tensioner causing oiling problems in my 11 years of being into sport bikes. Not an issue IMHO.

Russian 14 owner made comment on one of my tensioner vids:
4 months ago, you said, "That's total bullshit, man. Those wire rings (guys) have nothing to do with perceptible noise...." Listen 'sweet potato' this is a yes or no question: your trousers will fall down without a belt holding it in one place. Are we on the same page so far with a yes? What point you are missing is that the ring acts the belt, the ratchet piston acts the trousers, but you are saying the ratchet piston does not slide back and forth like a beltless pair of trousers you keep lifting to adjust to remain in one spot.

Yes or no, did adding tension to the ring stop the piston from ratcheting over part of the ring that can no longer lock it in place? Yes says my simple mod. Sweet potato here cannot translate the noise from the engine pulse, the for every action is the equal, but noooooo, toss those aside, potato nuts here has the answer.

Engine noise only sounds one way... floor is yours.

Racing tensioner: Needs monitoring so say two races you pop the crank cover, move the crank cw/ccw to note the slack, then readjust.
OEM tensioner: Has a long piston and can automatically ratchet to the next tight position once the chain mechanically wears at the cam tooth and chain links, plus digging a groove in the slipper. Wire ring locks the next ratchet groove.

Graduate of Click Engineering.

* Last updated by: Hub on 12/4/2019 @ 10:26 AM *

Racing tensioner: Needs monitoring so say two races you pop the crank cover, move the crank cw/ccw to note the slack, then readjust.
OEM tensioner: Has a long piston and can automatically ratchet to the next tight position once the chain mechanically wears at the cam tooth and chain links, plus digging a groove in the slipper. Wire ring locks the next ratchet groove.

Maybe if you are racing you'd need to adjust a manual tensioner. I've redlined many times since installing my APE in about 2012 and I never have adjusted it after installing. I wouldn't bother adjusting it unless I heard the rattle come back.