any info for cam chain issues?

[hedgiesfu]

hey all, i've started hearing the cam chain on my engine, i believed it was going slack yesterday once the engine warmed up.
this afternoon it sounded much worse, like it was slapping on the edge of the tensioner blades.
what to do? adjust or replace the cam chain? and how?

engine is at 42000 miles (68000 km)

bike is 21 yo, coil on pot 2 replaced, firing and starting very well,  despite steady, regular popping on the exhaust

any ideas?

[tjmann0]

Don't run it anymore until you have sorted the problem you could do serious engine damage , I have heard that the most common problem is the auto tensioner which is easy to change two bolts and access is easy , it works on a ratchet basis but if it slips the ratchet you will have a slack chain . If it happened suddenly it will almost certainly be that

[Sin_Tiger]

Don't panic just yet. As Mustang and some others have verified, the valves cannot hit the pistons on these engines.

If properly serviced during their life these chains / guides can go for big mileages before needing replacement.

The chain tensioer is an automatic type relying on a spring under the cap to maintain a steady pressure on the guides, so there is no way to manually adjust the tension, unless some miss guided individual has b@$tardised the tensioner as in the pic below (If that's case you'll need a new cap and spring whatever you find).

The easiest way to do a quick check is to remove the chain tensioner, check it's free, the teeth are not worn and have a look at how far it's extended. It's quite straightforward, doesn't need any special tools or parts and can be done without taking any bodywork off.

1 - Remove the right crank cover, second from the front with the sensor wire going into the upper rear edge. don't worry if you damage the gasket and you don't have one, you can get away with gasket silicone until you get a new one. Under that you will see the timing disc held in place with a 24mm AF nut and sensor to the rear.
2 - Put the bike in 5th or 6th gear and turn the engine until the no1 TDC mark aligns with the timing sensor, trying to turn the engine using the 24mm nut with the plugs in isn't recommended to prevent damage to the disc retaining nut as you will likely have to put a fair bit of force on it. At this stage having the engine at No1 TDC is really irrelevant but it's good practice to have a starting reference if you go further.
3 - The Triumph bible recommends supporting the rear tensioner blade with some sort of wedge to maintain some tension on the chain while you remove the tensioner, up to you.
4 - Undo the tensioner cap nut (19mm AF) KEEP PRESSURE ON THE CAP NUT unless you want to be scrabbling around looking for it and the spring after you've stopped swearing at your skinned knuckles, remove the cap and spring now.
5 - Undo the screws holding the tensioner body (8mm AF) to the rear of the casing and remove as carefully as you can in order to prevent distrubing the ratchet pawl position, same story as above with the gasket.
6 - Note the number of serations exposed to the right of the pawl. If there are still at least 4 clicks to go then you should be OK for a few k miles yet, if it's extended all the way then it's time to go deeper and look at replacement of the chain and blades, I wouldn't suggest just replacing the chain alone.

The pawl on the tensioner body can be pressed down at the rear against the spring to allow you to check that the tensioner barrel moves freely in and out without sticking, being slack or being able to rotate perceptably. The teeth on the barrel and on the pawl should be quite sharp with little or no wear marks, when you slide the barrel with the pawl released, the teeth should engaged cleanly with a snap and lock solidly against reverse pressure.

To put it back, release the pawl and push the barrel back until there are no serations showing, refit the body only, push the barrel against the chain blade with your pinky before refitting the spring.

A good description with some excellent photos is in a post by JetDox here. I would recommend getting friendly with the forum Search function as you can save a lot of grief and time with it.

[London_Phil]

More info and part from Sprint Manufacturing. I had a shortish spring, and fitted (easily) this replacement without taking anything except the tensioner off.

http://www.triumphparts.gbr.cc/product.php/5373299/

Regards

Phil.

And more info fromTriumphRat.net

http://www.triumphrat.net/hinckley-classic-triples/644297-cam-chain-tensioner-spring.html

[Sin_Tiger]

More info and part from Sprint Manufacturing. I had a shortish spring, and fitted (easily) this replacement without taking anything except the tensioner off.

http://www.triumphparts.gbr.cc/product.php/5373299/

Regards

Phil

Personally I would use a genuine part here, no disrespect to Trevor as I have bought a lot of stuff from him but nearly all his parts are after market suppliers, i.e. not genuine Triumph.

[JoeDirt]

Personally I would use a genuine part here, no disrespect to Trevor as I have bought a lot of stuff from him but nearly all his parts are after market suppliers, i.e. not genuine Triumph.

with Sin. You are protecting your engine from a total meltdown... with a 10 cent screw.

[threepot]

I've just changed the chain on my bike. 60k miles. Bike running well,no unusual noises etc. But when I took the tensioner body out,it was hardly under any tension. Plunger was nearly full out! If you find the same,time for a new chain?
Are you able to do the job yourself? If your mechanicaly minded,you shouldn't have a problem? Plenty of advice on hear

[hedgiesfu]

i'll manage the job myself threepot, ty for the concern, as long as i can find guidance when i need it i wont have any issues.
i was thinking about a mechanics course at a local college, some of the students reckon i wont learn anything in the first year

not afraid to get my hands dirty, beats paying labour costs
might document the job, just for fun, if it goes well i will do the mustang method on the rims

for my camchain to bugger out at 42k, i must need to chill out on the roads, though i did go from a zx6r to a steamer, might have something to do with it 

[nickjtc]

So, pardon my ignorance, but did they make the cam chains on these bikes out of chocolate or similar? Can't say I've ever come across an instance where the chain needed replacement...... Tensioners, on the other hand.........

[Mustang]

you should see how much the cam chain grew in my Nissan 4 liter truck .
you could literally lift it off the sprockets without loosening anything ...............it only had 60 k on it 

its the sliders/shoes wearing more than anything , but while there a new chain is cheap compared to catastrophic engine failure .

[threepot]

It's not that expensive a job,providing you don't need any guides? I bought a Morse chain,a few shims,New spring,cost about £90.

[threepot]

Old v new