Setting the Camchain Tensioner

BarrieC

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Hi Guys,
Nearly ready for top end put together, last bit is ensuring I know initial setting position of Camchain adjuster. Mines a Type D (after I pieced all the bits together)

All the manuals, books forums say to use the adjuster rod being flush with the end of adjuster screw as rough guide. The bike (bits) did not come to me with any damper washer, but i feel the need for something to keep the spring central.

Without a damper washer the spring is about full compression before the rod reaches the end of the screw tunnel - is that right? should it be so highly tensioned?
If I add the concave washer to the mix even tighter or not reaching the end.

I understand this may be down to experience for how much force is put on the tensioner, but i do understand that the end of the rod should be able to move in and out slightly as the engine runs.

any advice gratefully received and taken on board!

Happy Holidays! - as you guys say

Barrie
 

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Without the damper washer, your rod will come out past the end of the adjuster screw when fully compressed. Your first pic shows this. If you set the adjuster so the rod is flush with the end, your setting will be too loose. Easiest and best way to set the tension is while the engine sits there idling. Then you can watch for the slight in-out movement of the rod (maybe 1 to 2mm is a good setting). If the rod doesn't move at all, you've set the adjustment too tight.

My suggestion is to get a damper washer. You can buy bags full off eBay for not too much money .....

DamperWashers2.jpg


You should also consider upgrading your type D assembly to a type E. It's a "must do" mod in my opinion. Details on the "how and why" are here, see posts 22 and 23 .....

https://www.xs650.com/threads/cam-chain-tensioners.1056/page-2
 
thanks, 5twins, just so its clear in my mind: the spring should be at full compression, but be able to take up any slack as it appears in the chain movement - which is why you can see the slight movement?

Will junk my planned damper washer, as i have the copper washers required - just my understanding was flawed

Just had a look at your link, and how they reduced the screw length, nice write up, i may even have type E parts amongst all my "stuff"

Cheers
 
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IM(not so, LOL)HO "a bit of movement" is more important than any set "distance" in or out
1mm or about 1/16" inch for start up and intial run in will be fine.
if you have an e-start; spinning the motor, spark plugs out is an easy way to see this before trying to start it.
 
IM(not so, LOL)HO "a bit of movement" is more important than any set "distance" in or out
1mm or about 1/16" inch for start up and intial run in will be fine.
if you have an e-start; spinning the motor, spark plugs out is an easy way to see this before trying to start it.
:agree:

If you use the rotor nut to rotate the crank, you'll "feel" the cam come up on valve overlap on one of the cylinders. The exhaust lobe is trying to rotate the cam one direction and the intake lobe is resisting. It's actually pretty strong as it'll try and snatch the wrench out of your hand. Once the cam is "stuck" there, you can try and rotate the rotor back and forth (rock the wrench) and you'll see the rod moving in and out.
This is the procedure I use to set tension. 1-2mm or as Gary sez... about a 1/16"
I've warmed the bike up and rechecked while it's idling and it's pretty much the same amount of movement.
Since you need the rotor cover off to adjust the valves... and that's a good time to also check the chain... or vise versa... it's the easiest way I've found to set chain tension.
 
IM(not so, LOL)HO "a bit of movement" is more important than any set "distance" in or out
I agree. The crank pulls the cam with the front of the chain and the adjuster is to dampen slop in the rear. Too tight, no movement, the chain will eat the rubber track on the rear adjuster. Interesting how it pulses, presumably even with a new and uniform chain. Something to do with the natural resonance of that length of chain maybe
 
Well, I think even a new chain has some minor high and low spots. I check and set mine (if required) at every oil change, or about every 1000 miles. It's best you check it more often than the book says, and it's so easy there's really no excuse not to. I also like to check it when the engine is hot. I used to set it on a cold engine but when I checked it after the motor got hot, I found it too tight, probably due to parts expanding. So, my routine now is get the motor hot for the oil change, check/adjust the cam chain, then dump the oil and pull the filters.
 
Is it a new chain?
They will bed in, force some grease out of the pin/socket and just generally grow a bit in the first couple hunert miles.
It's typically a fight just to get a new chain ON the sprockets and staked.
 
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