How do I stop oil leak from the chain tensioner (1980 XS1100 SG)

[KIP]

Please Help !!!

[Socer4m]

HI,,,get the automatic tensioner from ebay,,,many yamaha models have it and you will never have to adjust the tensioner again,,,,anyway,,
1. ,pop the timing cover, rotate to TDC
2. remove the tensioner
3. clean the engine tensioner surface and tensioner
4. make, buy the gasket for the tensioner
5. use a good oil resistant, proof gasket cement like permatex 2 form a gasket,,,from any auto parts store
6 install to correct torque and pray it doesnt leak

a list of automatic tensioners should be in a search, or check the web as I dont recall the numerous models...
keep us informed, its a common problem on these old bikes so dont panic,,,its solveable....

[Socer4m]

https://xs11.club/forum/modifications/engine-aa/36428-automatic-cam-chain-tensioners#post535952

partial list of automatic cam chain tensioners,,,,lots available on ebay AND cheap,,,, Mike in S.Diego and Pa.

[bikerphil]

pop the timing cover, rotate to TDC

You want to put on the "C" mark, not TDC.

[jetmechmarty]

There are some nuances with some of the auto chain tensioners. Mine came from a 550 Vision. The mount bolt or bolts have to be shorter than stock as the OE bolts will bottom out. Also, my top bolt hole on the new tensioner had to be slotted to make it fit. Too far and it leaks.

26H-12210-03-00 is a V-Max tensioner. It's a popular choice and available new. That tensioner fits a bunch of engines.

Automatic Cam Chain Tensioners - XS11.club Forums This thread will tell you everything you need to know,

[Radioguylogs]

If you decide to keep the original tensioner, the problem is usually the rubber plug on the end becomes leaky (#15 in the diagram below).

The plug is still available from Partzilla for $4.49.

You'll need a new gasket as well (#20 in the drawing)

Also, there is an O-ring on the bolt that you use for setting the tension (#14 in the drawing).



Put the bike on the centerstand. (This line added 4/17/26 via edit).

Remove the left side crankshaft cover, turn the crankshaft so the pointer is pointing at "C"

Remove the the tensioner, clean it up, install the new parts, and reassemble.

It's a good idea to read the service manual for more detail.

[cajun31]

When your rotate the engine use a large wrench to turn it and make sure you turn it clockwise. When I was running the original tensioner before replacing it with the ACT as mentioned above I always rotated it around twice stopping at the C mark on the second go around. If you choose to buy and install an ACT (automatic cam chain tensioner) the procedure is basically the same as far as rotating the engine around to the C mark.

[Larrym]

When Adjusting the Cam Chain Tensioner per the repair manual (the method provided here as the way to remove/replace your leaking CCT...)? (O_o)

The maximum amount of chain slack is positioned to the front of the engine where the INSTALLED CCT keeps it from falling down/forward. (^_^)

If/when you REMOVE the CCT... this slack falls forward/down and may or may not be enough to fall off the lower sprocket and/or jump a tooth or two. (O_o)

If/when the chain jumps even ONE tooth the result is bent valves when the engine rotates again. （>﹏<）

Folks that have Removed and Replaced their own CCT per the method given without any adverse events apparently condone/support this method. (ʘ‿ʘ)

Folks that have done the same exact thing and bent valves (ruined their engine...) have been blamed for just "doing it wrong." (´;︵;`)

I see this as a prime example of Confirmation Bias-

Confirmation bias- people's tendency to process information by looking for, or interpreting, information that is consistent with their existing beliefs. This biased approach to decision making is largely unintentional, and it results in a person ignoring information that is inconsistent with their beliefs.

There ARE ways to R&R the CCT which do NOT risk the chain falling, slipping, and jumping teeth. (^_^)

The method thus far provided to you AIN'T one of'em. (；☉_☉)

HTH.

[speedlimit85]

If you still have the plug. Brake clean the area, then permatex gasket seal the edge of the plug to the tensioner. Then ride off into the sunset...

[DEEBS11]

I run a stock tensioner unit and to keep it leak free it needed 3 parts. Gasket, O-ring, and "Special Shape Plug". As others have mentioned, the setting on the timing plate is "C" and you can remove the unit to work on the bench. Clean it up and install the parts. Push the plunger all the way in and lock it with the side bolt (not too tight, you will distort the shaft). The seal plug must be installed with a good hi temp sealant. Let it cure overnight or it will leak. You can install the O-ring and gasket dry. When you install the unit, make sure you release the lock bolt and then re-secure it which will return tension to the chain. Mine has remained leak free for several years.

[DEEBS11]

..........

[jetmechmarty]

I didn’t see it posted, but the discussed repair should be done on the centerstand, not the sidestand. If the chain has enough slack, you don’t want it falling away.

[jetmechmarty]

IMHO, the OE tensioner works fine. Since new parts are available to fix the leak, doing so is probably the path of least resistance.

[DEEBS11]

Plus look at the cost of the 3 parts.

[Bonz]

I agree with soccer4m and the process he described. Edit: other than TDC, "C" is correct.

I don't see it as being the gloom and doom that is being made out to be. Back on the old forum, I couldn't begin to count the number of guys that successfully did it. Yes, there were a few that had problems. Imo and from experience, with an ACCT from the multitude of Yamaha bikes/ATV's that can be found on ebay, the ACCT is the ticket. The confirmation bias strongly favors those who have been successful.

With that...

Can you explain more how to R&R without removing? That could be a very helpful process.

The leaking was the genesis of putting on an ACCT. I don't recall reports of leaking once installed properly. And did I say, never need to adjust again?