Cam chain replacement

Alright, now I have all the parts and the time to fix my Berg, since my rocker cover exploded.

I have the upgraded cam chain, along with the new plastic tensioner arm and the new tensioner itself.

What steps and precautions do I need to take when replacing the cam chain, so I do not mess up my timing?

Obviously, taking pictures prior to removing the old chain will be necessary.

Also how is the clip removed and how is it replaced? (I like to ask these 101 questions, I never know for sure how to do it).

Thanks in advance!

And I will try to make it for Moab.

so if i have this right froggy, despite exploding the top cover, the chain is still on the camwheel and all good?

ok this is what i would do:
preparation
turn the engine counting the links. double check again. then, using a 4" bench grinder, take the **** off at the correct link on the new chain, lever the plate off, pull the link and clean everything up. last time i did it, i wedged a flatbladed screwdriver through the link whilst i was grinding and held the chain back with my left hand. ify that - get ken on it!

task
i would get that cam the 11 and 1 o clock position, use a ruler diagonally across the two lobes - is the ruler parallel to the head?
scratch a mark on the flywheel and crankcase or better still use a bolt in the top flywheel cover hole and something pointed aiming at your mark. you now have a surefire way of getting the cam timing back 'as was' if all goes wrong.

remove the old tensioner.

turn the engine at the flywheel with a T-bar and socket till the camchain split link arrives at the 12 o clock position.

i would use ken at this point for help and put him on the T-bar.

with broadnose pliers - undo the split link and note the direction it faces. IF it was an < arrow head it should point the way i just did this. right? remove the sideplate as well.

roll out the new chain and have it come over the front of the head. ideally a third person would hold the chain from near the left bar otherwise you just gotta muddle through froggy!

as you pull the link out the back, hold down both parts of the chain onto the sprocket. push gently a screwdriver in between the tensioner and the chain so at leqast one side can't jump a tooth.

lift the left link up and fit the link through the chain in the engine and the new one as well. don't worry about the sideplate but DO fit the circlip (in any direction here).

so now you have a new chain connected to the old chain. now you must remove the screwdriver whilst 'pinning' the chainS down with your fingers. IT MUSTN'T JUMP A TOOTH!

SLOWLY, VERY SLOWLY, TURN THE CRANK CLOCKWISE WHILST DOING THE FOLLOWING ACT OF PURE GENIUS: remove the old chain out the back, whist feeding the new chain down the front. the third person could be dropping one chain whilst lifting out the old.

when the new is in and all the way around the engine. remove and get rid of the old link whilst holding the chain down. fit new link, side plate and the link facing your < left.

fit the tensioner.

turn crank to your scratch mark. the ruler should now tip over so slightly down towards the front wheel spindle. you have a new unstretched chain in there.

all good?

button it up and start it.

you could if you wish, make a mark on the camwheel as well as the one on the crank. say "sod it" remove the chain and fit the new one whilst playing with the camwheel like a kid as you try and get your scrath to line up.

nick. you owe me a beer!

regards

Taffy

PS apologies for not being clear!

Thanks, I will read this several times. Yes the chain is still on, probably still good but I don't want to run a risk!

I will work on it in my evenings this week.

yeh, i felt the same way. there it is, a good chain. a happy and complete chain! but you just don't know what it went through. so really grit your teeth and fit the new one!

you've got to be at MOab froggy coz i want to nick your works suspension when you're not looking!

regards

Taffy

regards

Taffy

I think I am going to use a big fat marker and make some marks on the side of the wheels to remember their exact position. Is this a good trick?

Front valve stem points to 10:00, rear points to 2:00.

;~)

Ok I got it for the top part, but what about the bottom part?

Hey Taffy

Pardon my ignorance and inexperience but I'm new to this game as well and could be doing same thing soon.
You say "take the **** off at the correct link".
Why does it matter which link you grind up?
How do you keep all the crap out of the bottom end?

coastie

it's no different to you checking the links on your final drive chain? you count the old chain and cut the new one to the right length. surely coastie that is obvious?

to be exact, i get a screwdriver and lay it in the vice at 20 degrees from the horizontal. put the chain link you need to grind off astride the screwdriver and then pull the other two bits back like you're restraining a dog.

the two nipples you want are sat out there loud and proud.

as you aren't doing this on the bike - there is no swarf.

hope this helps.

froggy
you want the thinnest line you can mate. scribe a line with a sharp object. be deadly accurate.

regards

Taffy

Hmm how accurate do you have to be since the smallest variation is equivalent to that of a chain link, Taffy?

OK sorry Taffy I'm with you now.
I thought you were talking about grinding a link off the old chain while on the bike to split it.
I was thinking that sounded pretty rough.

Shayne

incorrect froggy

the new chain will be shorter. it may be that the cam sits correctly with the flywheel line slightly forward of your mark then having swopped a tooth the cam would look good with the line the same distance back. all you need now to screw it is a big fat 4mm felt tip line.

be deadly accurate froggy. then make allowance for about 2mm travel at the link. so for instance if the first nipple of a plate was half under the cylinder head and half above. the next time with a nnew chain that camwheel will have turned 2mm at the circumference anti clockwise and therefore you will see nothing at all of that first nipple.

that 2mm at the camchain is about 5mm at the flywheel.

remember, when you're confused - it's too late!

regards

Taffy

you can get the old cam chain off with a bicycle chain braaker. cheap and no gtinding invoved. you can press the old pin back in just like on a linkless o-ring chain with a pair of channel clamps , then push it through with the chsain breaker and re swage with a punch and body dolly or some such solid wight.