Primary chain hydraulic regulator

[elcochinato]

Hi, the primary timing chain is rattling a bit. I removed the oil pan to inspect it, and aside from being able to move it slightly with my fingertip, I was getting ready to replace it. Then I found the hydraulic tensioner is leaking oil from the washer that presses against it.

My question is, can the tensioner be removed without removing and disassembling the entire engine?
How can I measure the wear, or how can I tell if the tensioner has reached the end of its travel, or if it loosens when it loses oil pressure?

 

[elcochinato]

Does anyone have any idea about this?

 

[MP-x]

Hi elcochinato,
primary shaft tensioner is held in place by three bolts from the primary shaft/chain side on crank case, and replacement means engine out & case split.
See https://www.cb750c.com/publicdocs/C...viceManualChapter12CrankshaftPrimaryShaft.pdf
Also attached couple of photos of my crank case split two years ago, there you can see how the tensioner is placed.
When case halfs were assembled, the tensioner slipper was secured in place with wire, so that the plunger and spring would not fall off, when lower case half was mated to upper half.
There is no real description on how to determine 'extensive wear' of the tensioner slipper on the workshop manual, but if primary chain is rattling as you say, I'd take the engine off the frame and check the chain, tensioner and big end..

 

[elcochinato]

Hi elcochinato,
primary shaft tensioner is held in place by three bolts from the primary shaft/chain side on crank case, and replacement means engine out & case split.
See https://www.cb750c.com/publicdocs/C...viceManualChapter12CrankshaftPrimaryShaft.pdf
Also attached couple of photos of my crank case split two years ago, there you can see how the tensioner is placed.
When case halfs were assembled, the tensioner slipper was secured in place with wire, so that the plunger and spring would not fall off, when lower case half was mated to upper half.
There is no real description on how to determine 'extensive wear' of the tensioner slipper on the workshop manual, but if primary chain is rattling as you say, I'd take the engine off the frame and check the chain, tensioner and big end..

Hi elcochinato,
primary shaft tensioner is held in place by three bolts from the primary shaft/chain side on crank case, and replacement means engine out & case split.
See https://www.cb750c.com/publicdocs/C...viceManualChapter12CrankshaftPrimaryShaft.pdf
Also attached couple of photos of my crank case split two years ago, there you can see how the tensioner is placed.
When case halfs were assembled, the tensioner slipper was secured in place with wire, so that the plunger and spring would not fall off, when lower case half was mated to upper half.
There is no real description on how to determine 'extensive wear' of the tensioner slipper on the workshop manual, but if primary chain is rattling as you say, I'd take the engine off the frame and check the chain, tensioner and big end..

Hi, thanks for the reply. I've noticed that the tensioner is leaking oil from the gasket underneath the crankcase. Seeing this, I think that if it's leaking oil there, it's probably preventing the primary chain from tensioning properly, even though the chain still has some life left.
Therefore, to avoid disassembling the engine, I'd like to know if the valves can be removed from underneath without loosening anything inside the engine.