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erik
1st September 2005, 23:07
My bike's done about 72,000km and is fairly rattley.
I'm thinking of pulling the rocker cover off and having a look at the camchain tensioner and the slide/guide things to see how worn they are and then probably replacing the camchain.
I haven't ever replaced a camchain before, but I've done the valve shims and think I should be ok doing the camchain, provided I can get my hands on a camchain breaker/joiner thing and figure out how to do it properly.

Does anyone know if the camchain tool has to be a special yamaha one or not and does anyone possibly have one they could lend me? I haven't tried phoning any shops about them yet, thought I'd ask here first. If I have to and they're not way too expensive, I'd rather buy the tool and do it myself than take the bike into a shop to get a mechanic to change the camchain.

WRT
2nd September 2005, 08:01
Ok, one of the mechanics round these parts should be able to help more than I can, but for what is worth, I have been told (in particular with regards the older model bikes) that if your tensioner is giving up the ghost, then you are better to replace it with an aftermarket manual one rather than put another automatic one in. Apparently they are prone to failure, and the manual ones work much better. Have also known guys to make up their own ones from the leftovers of the automatic one with a bolt up the middle of it to provide adjustment, and they have worked fine.

erik
3rd September 2005, 11:19
Thanks for that.

I took the bike apart a bit yesterday and had a look at the camchain and tensioner.
I pulled the rocker cover off before removing the tensioner and the camchain was pretty loose, I was able to push it down maybe 1cm or so between the cam sprockets.

I wasn't able to remove either of the camchain guides, the front one needs the front camshaft taken out first, and I think the rear one might need the crankcase to be split, so I guess I'll have to assume they're ok enough.

I removed the camchain tensioner, it's the automatic type with a plunger with a ratchet and a spring behind it. It was only about half way out of its available travel.
When I put it back together, I tried to see if the tensioner would tighten the camchain any more, but it didn't, so I manually pushed it in another click (about 1mm) from its previous position which seemed to improve the camchain tension.

Does anyone know how to tell if the camchain needs replacing or if the tensioner is just not doing its job properly?
I tried wiggling the chain forwards and backwards, but it was hard to tell if there was any slack between the links. I tried measuring the length across 11 links with some calipers, but haven't been able to find info about what the length should be.
I haven't tried running it yet, so don't know if the rattling is improved. I'll give it a go today when I change the oil.

erik
3rd September 2005, 21:34
started it up today and it's sooo much smoother.
I think I'll just leave it as it is and if it starts rattling again, tighten the camchain tensioner manually again.
Now I've gotta figure out why my forks are squeaking so much, and if it's a problem...