Savage_Rob wrote on 02/05/08 at 11:43:16:Yup. The sometimes widely varying lifespans could be an indication of inconsistency in parts quality but, as Reelthing said, could also be maintenance and riding habits.
Polar_Pilot wrote on 02/05/08 at 15:16:55:This is an interesting post. Back a few years ago the best Board in the world was run by Bert Hesse from Germany. In the years his board exsisted I do not remember much discussion ever on cam chains or any discssions of design faults.
This board on the other hand is riddled with discussions about the so called "design fault". One guy on the old board had 76,000 miles on his Savage without any problem what so ever. I blew an engine on my 89 at 15,000 miles but the fault was entirely the riders - I did not check my oil, heard the clicking noise start and about 100 miles later the engine was toast. But it was not a design fault it was 100% rider error
Demin wrote on 02/05/08 at 15:28:21:I think alot of the problem is that people bought the bikes as starter bikes, abused them a little while learning aka over revving,not checking oil,etc. sold them to move up to a bigger bike or whatever,then we come along and buy them probably at the point where the work needs done.My'86 had 12,000 miles + or - and the adjuster had fallen apart.(Thank goodness for this website and the mechanical gurus here)My '87 has 7,000 on it and the adjuster is about halfway out already.Plus alot of it is riding style and how they are maintained
Some first rate sense is being talked here. The oil thing is likely to be key to the whole problem. The bike I just bought was about mid-way on the tensioner at 8000 miles, but the cam and followers had gone because there was only just over a pint of oil in the bike!! The previous owner knew it was tapping but never thought to check the oil – (nor did the bike dealer he took it to with the noise). The bottom end, bore and piston were perfect, but the cam and followers were bad; it would seem that a low oil level will lube the bottom end through splash but that the pump won’t be fed enough to supply the top end, which you’d expect perhaps.
I’ve worked with and know a few Germans and they’re really fastidious on maintenance – not likely to let their oil get low or leave it in the sump too long. And – most of Germany is a whole lot cooler than the US all year round, so the oil isn’t being worked so hard and you’re less likely to get lubrication problems.
It all points to the cam chain and guides needing to be well lubed – the problem is obviously not the cam chain itself, as it keeps within limits, so the slack is growing elsewhere. Maybe the guides, or the sprockets, or maybe a little guy sat at a drafting table in Hamamatsu got his math wrong when he worked out how long the tensioner mechanism had to be to take up cam wear. I think it’s the latter – that’s a very long chain run on the Savage, and a short tensioner throw!
We can have 1.8mm wear on 10 links, and the chain is something like 60 links long. 6 times 1.8 gives 10.8mm of extra chain length at service limit. That’s a lot! Now, back of cigarette packet calculation here because I’m at work and can’t measure the bike, but the cam sprockets are roughly –say – 12 inches apart, so for simple trigonometry the tensioner is pushing between new chain and service limit chain 2 ‘triangles’ with adjacent side of 6 inches, and hypotenuse of 6 inches plus 5.4mm. Do the Pythagoras we learned when we were in short trousers, and you get the third side length to be 40mm – that’s the outward extension due to wear, or how much the tensioner needs to move! I know the measurements are way out, and the layout isn’t a perfect triangle, but it does raise doubt whether the chain length/wear might simply exceed what the tensioner can do. I’ll measure and confirm if I get time at the weekend, unless somebody else gets there first.
Either way, things wear less – a whole lot less – when they’re well oiled. Use a good quality synthetic oil, 0W-40 or 5W-40 in temperate climate and 15W-50 in a hot summer, and make sure it’s kept topped up towards the top of the glass all the time.