Guest bruinfj09guy Posted August 24, 2015 Share Posted August 24, 2015 So I've read other threads talking about how the spec chain tension is a little tight. After running my chain for about 3k miles adjusted to spec (and regularly lubed) I noticed a "popping" noise while rolling my bike not running. The noise was a little louder when the chain was hot. I inspected my chain and removed the front sprocket cover. There are some grooves where the outside of the chain fit in to what I'll call the outer hub of the sprocket. Are these grooves present on a new sprocket, or have I worn into the wells of the sprocket causing these grooves. After re-lubing the chain and loosening slightly (to the outside rather than inside neighborhood of spec) the popping noise is less noticeable. I'm just wondering if I was actually over-tight and caused damage. See pic and opine freely. Perhaps I am over paranoid. I don't know. [/img] Link to comment Share on other sites More sharing options...
pattonme Posted September 4, 2015 Share Posted September 4, 2015 the only reason to machine the sprocket like that is there isn't room for standard chain height. I don't see anything located remotely close in the pic above. Can we get a picture to the left that might show why Yam thought they needed to reduce overall diameter of the sprocket+chain? How many teeth on that sprocket? Maybe they designed the cases around say a 16 but then later decided a 17 was more appropriate but had to cut it down so the chain would fit. Link to comment Share on other sites More sharing options...
gregman Posted October 1, 2015 Share Posted October 1, 2015 the only reason to machine the sprocket like that is there isn't room for standard chain height. I don't see anything located remotely close in the pic above. Can we get a picture to the left that might show why Yam thought they needed to reduce overall diameter of the sprocket+chain? How many teeth on that sprocket? Maybe they designed the cases around say a 16 but then later decided a 17 was more appropriate but had to cut it down so the chain would fit.What? No... The sprocket diameter is completely dependent on the tooth count. A 525 17t sprocket will be exactly the same diameter as any other 525 17t sprocket. There is no way to "cheat the system" and make a smaller-diameter 17t sprocket. As was mentioned before, the large "hub" area is supposed to contact the chain in order to quell side-to-side movement (and thus extra noise). As a side note, Yamaha has said that the 1/2" slack mentioned in the manual is a typo. I have been running 3/4-1" slack on mine, noise has been much less, I don't have to lube the chain as often (since it doesn't get as hot), and have 8,000 miles on the stock chain and sprockets with zero tight spots and no hooking of the sprockets. '15 FJ-09 Red is the fastest color! Prototype Parabellum screens Shogun sliders SC seats Radiator screen Link to comment Share on other sites More sharing options...
Premium Member ULEWZ Posted October 1, 2015 Premium Member Share Posted October 1, 2015 As a side note, Yamaha has said that the 1/2" slack mentioned in the manual is a typo. I have been running 3/4-1" slack on mine, noise has been much less, I don't have to lube the chain as often (since it doesn't get as hot), and have 8,000 miles on the stock chain and sprockets with zero tight spots and no hooking of the sprockets. Can you show the proof on this as I heard quite the opposite from multiple Yamaha Principals. I am hoping you can find the proof though. linky A government which robs Peter to pay Paul can always depend on the support of Paul. George Bernard Shaw (1856-1950) Bikes: 2015 FJ-09, Seat Concepts seat cover and foam, Cal Sci medium screen, rim stripes, factory heated grips, Cortech Dryver tank bag ring, Modified stock exhaust, FlashTune with Graves fuel map, Cree driving lights, Aux power socket. 2012 Street Triple type R (Wifes) 2007 FJR1300 (Sold!) Link to comment Share on other sites More sharing options...
toonbobo Posted October 1, 2015 Share Posted October 1, 2015 For what it's worth, my FZ6 had the same grooves on the front sprocket. I thought it was a design for the link lobes to rest in. Link to comment Share on other sites More sharing options...
pattonme Posted October 1, 2015 Share Posted October 1, 2015 Personally I would ignore Yamaha's so-called spec for chain tension and adjust it for sufficient slack to be loose (not floppy) at all suspension positions. Nobody else in the industry runs chains that tight, so official admission or not, it doesn't change the fact that it's very obviously wrong. Now, if you want to make a warranty claim against Yam for ruined counter-shaft bearing and seal, and pre-mature replacement for chain and sprockets, you're probably going to need an official statement of guilt. Link to comment Share on other sites More sharing options...
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