So I recently got my first bike, a dr350se and no its not the salvage one I was asking about a couple of weeks ago. Its a clean street legal runner, I've rode it a couple of times with no problems now.
But this morning I went to warm it up and it didn't seem normal, then I hear some strange sound and I see this line hanging down melting on the exhaust pipe!
It comes from the bottom of the fuel tank, I assume its a breather or something, Don't know where it was before, looks like it was just knotted and tucked up somewhere. What is this and where does it go? It should also be mentioned that was having a hard time warming up and any throttle killed it immediately, its 75 degrees out and it wasn't this touchy the other times.
Additionally occasionally I can hear a hissing/buzzing from somewhere near the top of the forks, its not the tires, haven't lost any pressure in 2 weeks. I did my best to listen and check lines but couldnt find the culprit any ideas?
Is that your vacuum to your fuel petcock? If it isn't pulling vacuum is isn't running as a safety feature.
http://www.thisoldtractor.com/dr350_manuals/workshop_manual_dr350.pdf
Greg Bender's site referenced above is an awesome resource:
http://www.thisoldtractor.com/dr350.html
Back to the question at hand, the petcock is on the other side of the bike from the dangling hose. Although I'm very familiar with much of the DR350, and have owned multiple, I've never owned one with a stock steel (SE or street model) tank or a stock vacuum petcock! The dirt-only models have a different tank/carb/petcock, which I'm also not too familiar with. If you have questions about aftermarket plastic tanks (Clarke/Acerbis) on a street-legal SE with a Yamaha Raptor petcock (super-common setup) I'm your man! I suspect that the hose could be one which is supposed to connect to a charcoal canister, which should be tucked up under the tank near the coil, and may not be visible without removing the tank. Is your bike a California emissions-compliant bike by any chance? And it should be noted that I'm going on a fair bit of guesswork here.
As for the noise, when does it present itself? While sitting in the garage? While running? While riding?
If you hear it again and can do so safely, try grabbing stuff with a hand and see if the noise changes or goes away. (Especially clutch lever, control lines, cables, gauge cluster, headlight shroud, headlight, turn signals, etc.) There is tons of little stuff that can vibrate on a single cylinder dual sport, even more so one with knobbies. Clutch lever pivots tend to have a little play so they can move when needed, and the cable has a little slack when properly adjusted, so they can buzz at certain rpms. See if the lever is rattling in the lever perch, or rattling against the handguard if so equipped.
Could be air escaping from the fork bleed screws.
In reply to ae86andkp61 :
yes they do come with stock vacuum petcock but the previous owner has replaced the vacuum one with a manual petcock. It is also a california bike so Yes! evap tank would make sense, although it definitely doesnt have one anymore. And the noise is best audible at idle and while going under ~5 miles an hour, but I'll do some more testing to see when exactly it goes away. Thanks
