Scraping sound only when drive engaged

[actionverb]

Hello everyone,
Got a new problem that I can't find much info on. Started get a weird scraping sound only when the drives engaged and I'm rolling. Sound like a chain over metal. Not so much a grinding sound. Rolling with the clutch in and it stops. Little hard to hear over the exhaust. If I had to make the sound of the timing chain scraping the valve cover, this is the sound I'd make. Anyways, looking for a suggestion as to my best place to start. Thanks

[actionverb]

Alright, well... bikes on the stand for a bit for paint and some other odds and ends. If I figure out the cause of the sound will post and hopefully it helps someone in he future

[dirtyrider]

Sounds like the front drive pulley to me.

[knoizy]

I wondered that but a worn pulley is more of a rumble or dull click if you ask me. Easy ten minute check though remove the cover and belt and if there's any play at all on the pulley that could be your culprit. Re-install with plenty of grease and that should buy you a few miles of silence to check if this is the cause. 

[actionverb]

Thanks guys. Really appreciate the pointers. Front pulley has at least a 1/16 of movement, maybe a bit more. Belt and all spline teeth appear fine. Put back together tightened down, no change. So any slop at all is a bad thing? I found no signs of rubbing or wear on amy parts.

[knoizy]

Hard to be sure but 1/16th play could well be the problem. Belt tension is often the real culprit and in my case the 454 was the first belt drive I'd owned and I was prone to taking the slack out of the belt because tighter is usually better. Wrong in this case as the belt likes to be *lots* slacker than you would think if going by feel, any tighter and the front pulley begins to suffer. When I replaced the pulley there were no real signs of wear on any splines and everything looked OK but the new pulley was clearly more of a snug fit on the splines and the problem was solved. 

Try adjusting the belt to and easy inch of dip by hand, pack the pulley splines with grease and see if your first mile or so remains quiet, that's all I can think of apart from just buying a new pulley.

[pya977]

just check that the rear sprocket outer chrome ring is not rubbing on the inner chain guard

[actionverb]

Hey. Im slow as sheet with responding. Think you nailed it with the front pulley suggestion. Greased and it quiets down. Tested a few time this summer. Replacement on order. Not a cheap part

[actionverb]

Replaced the pulley and confirmed good to go. Thanks again for the advice.

Just this summer new front pulley, replaced forks with rebuilt ones as mine had pitting from rust that kept damaging the seals (so nice not to be leaking all over the place), new shocks as one of my Ebay sv650 (I think) shocks developed a horrible squeak, new clutch lever. Now for a new ignition and paint. Mostly loving the process.

[knoizy]

Happy days, mostly living the process here too because as soon as I started to investigate what I suspect is an igniter fault on the 454 my 4x4 overheated and the past couple of months have been a rebuild of its cooling system. Its a 1996 Pajero and compared to European cars is enjoyable to work on thanks to the Japanese obsession with precision and making engines that can be fixed rather than dumped! Anyway it turned out the head gasket was rotten, the head tested OK and thankfully survived the overheating so its had new everything else with a bigger radiator. I also fitted a digital coolant temp display, a simple bit of kit but tells you a lot about the engine you can spot exactly when the thermostat opens, how well the fans are cooling and how hard its working in general. Fixed now so hopefully I can return to the bike while there's a bit of the season left!