ACCT revisited

[James England]

I was toying with the idea of putting an ACCT on mine but with some of the problems I have been seeing over this summer with the use of them I believe I will stick with my original. Hate to see you are having the problems you are and I hope the valves are not bent. From your last post it doesn't sound promising.

There are no problems whatsoever with the use of them. Only with the installation of them. If installed correctly, they are far more reliable than the oem one. You are much more likely to damage the engine with the oem cct than with the acct. If you read the entire thread, you'll see that the oem tensioner is extremely low-tech and prone to coming undone, leaking oil, slackening the chain etc etc. If you have a suitable acct, I personally would advise that you fit it, following the correct installation procedure....

[motoman]

There are no problems whatsoever with the use of them. Only with the installation of them. If installed correctly, they are far more reliable than the oem one. You are much more likely to damage the engine with the oem cct than with the acct. If you read the entire thread, you'll see that the oem tensioner is extremely low-tech and prone to coming undone, leaking oil, slackening the chain etc etc. If you have a suitable acct, I personally would advise that you fit it, following the correct installation procedure....

+1.......any hard decel WILL load front-side of chain, shoving tensioner back in. The shaft pinch bolt was at best a feeble attempt to call it such, aside from the housing fracturing from not being designed to take much of a side-load from the tightened set bolt.

[TopCatGr58]

Hey Cajun,

I had the OEM unit until this last year, worked just great for 30 years, even thru a top end big bore rebuild, and I always use engine breaking decel especially while running the twisties, just ask the other folks that I have attended the rallies with! Anyways, I should have posted that 30 minute cam chain tensioner mod thread link, because I posted/added to it my thoughts on it when I finally performed my MOD of the OEM unit vs. using an ACCT.

Regrettably it sounds like LOHO's chain was already worn to the max slack point, first even though his shorter ACCT measured to the correct ~45mm depth, it perhaps wasn't taking up the additional slack that had developed..
but more likely he had chain slack, and when removed the ACCT, the slack chain dropped down around the crank skipping a tooth or such.....even though he followed the adjustment positioning guidelines....that process puts the max SLACK of the chain along the front of the engine between the cam and crank, and so that's why it can drop/slip around the crank .....IF you don't take the extra steps I showed about taking the valve cover off, and using a wrench to rotate the exhaust cam a little to take up the excess slack on the ACCT front side WHILE you are removing the ACCT/oem CT unit before putting the new/modded one on.

IMHO, the ACCT's will allow a person to run the engine with more mile/hours and wear/stretch of the cam chain than the OEM would allow, and there's no quick/easy way of checking how much slack has developed in the chain....and there's this SET IT AND FORGET it mentality with the ACCT. Granted, they haven't been used that long on OUR engines, and so we haven't had anyone report a chain actually wearing/stretching so far as to FAIL/break! The OEM had a distance limit to the plunger, and when it reached that limit, the chain is considered to have worn/stretched beyond service limits, and should then be replaced. When it's stretched so far it can also allow the valve timing to be a few degrees more OFF as well that could also affect performance/mileage.

So...that's why I like the MANUAL MOD of the CCT and I provided the measurements that will allow folks to monitor how far in the tensioner plunger is IN towards the engine, so that I will KNOW WITHOUT having to take the CCT off when the chain has worn/stretched beyond service limits and when it will be time to replace it. YMMV!

T.C.

[jetmechmarty]

Once I actually got in there and did the job, I learned just how easy it is to replace a cam chain on the XS1100. It isn't very expensive either. For me, I think I'll just replace the chain every 60 thousand miles or so.

I think you can check it just like a drive chain. If you can pick it up off the cam gear, it's time to replace.

[bikerphil]

Another thing to think about with these ACCT's... I ran across one one time where it bound up after being installed in the engine and the pressure of the spring wasn't strong enough to push the ratchet. I had to file part of the side of the unit where it was binding for it to operate correctly. I always install them with the ratchet all the way out and push the actuator in with a screwdriver to verify it is working properly. BTW, running one now from a Vmax that has 90 K miles on the OEM chain and still going.

[Tenorman]

ACCT...Please look before I install it...

I purchased an ACCT for the 1980 XS1100LG....

According to the seller is was for a Yamaha Grizzly 550...3TB-12210-00-00

Does it look like it will work?



And does it matter that it does not have the black plastic pad on the "business" end


Thanks...


Tenorman

[BA80]

It should be fine. I hope bolts came with the ACCT because the ones for the stock tensioner are too long for the ACCT. At least they are for the Venture tensioners I've been using.

[DiverRay]

VERIFY that the body of the new ACCT is AT LEAST the same size as the OEM. I tried the wrong one, and it would not seal properly. You WILL need the shorter bolts for it as well. I don't remember the length, but I was able to use some "spares" I have around the man cave.

[James England]

I purchased an ACCT for the 1980 XS1100LG....

According to the seller is was for a Yamaha Grizzly 550...3TB-12210-00-00

Does it look like it will work?



And does it matter that it does not have the black plastic pad on the "business" end


Thanks...


Tenorman

Looks OK to me. when I first did the swap, I wondered about the lack of rubber block on the end of the plunger but, after consultation here, It doesn't seem to matter. The plunger is pushing on the springy steel tensioner blade and the CCT swap does lead to metal to metal contact, rather than rubber to metal. But there's loads of oil in there and it doesn't seem to cause any damage.

Here's what I used...a VMax tensioner

[Tobalcain]

how did you come to realize that the timing was 180 out. Im having trouble getting my engine started after a installing new rings..What did you do to correct the problem?

[DiverRay]

With the cam cover off, and spark plugs removed, turn the crank to TDC on #1. Both valves must be closed. I watch the valves as I get close to TDC, and look for the intake valve to be closing. IF the exhaust valve is closing, you are probably 180 out with the cams.
Others who have done this more may be able to explain it easier, but this is the best I can do.

[TADracer]

I know chain tensioners are like tires and oil, a matter of choice that may or may not have consequences.

I tend to side with TC in that a manual tensioner requires YOUR input and does not leave anything to chance.

Here is the one I made years ago on a drill press from a piece of aluminum, a few nuts and o-rings and a carriage bolt. This thing works and never ever gives me any problems whatsoever. Granted, you need to pull the valve cover to adjust it properly but then you should be doing that every so often to check valves anyway, right?

No ACCT's for me.

[TADracer]

Final score: three bent intake valves. I have two and am debating buying one valve or buying a head that has four for about double the price.

LoHo,

Since you will have your valves out (sorry about that), think about putting a 30 degree cut back on them all (especially the intake side) before you assemble the head. Its easy to do and any valve guy can grind them for you for just a few bucks each.

What it does is provide a smoother start to the flow of fuel when the intake valve starts to open during the overlap event. The process removes the little ridge that happens when the valves are stamped out.

Would I take the head off the bike and apart just to do this? Nope. But since you have your hands in the blood and guts already....... Its just one of those little things that add up to performance.

Before is on the right and after on the left.

[LoHo]

Thanks for that tip Mike. I finished her off last weekend and rode her to work all week. I plan to do something stupid and bend some more valves next spring, so I'll keep your tip in mind.

Tobalcain, take off the valve cover and pull the plugs, then set the timing to T and verify that cylinder 1 is TDC. Make sure the dots on the cams line up with the marks on the cam bearing 3. Then go to the right side of the bike and see if the cam sprockets show a small molded-in tab that points up from where the cam-to-sprocket bolt fits in. If one or both of the sprockets are 180 out, the bike will almost run right, but will never really be quite there. Make sure that that is all correct before you start trying to solve the problem by fooling with other things.

I think Crazy Steve has a pictorial of setting the timing which is invaluable. Do yourself a favor and go through the whole timing process to make sure each step is correct. Shortcuts lead to threads like this one.