Bad gas?

Trying to figure this out. My '08 450 has about 6400 miles on it now. Has been running great. I stopped in for fuel today, and put a little over a gallon of 93 in it. About a mile up the road it felt really vibey (more than normal). No new sounds other than it kinda sounds like the plastics are rattling off. It's definitely motor vibes. They go away when I pull in the clutch and let it idle down.

The only slightly concerning issue recently was some non-ferrous metal flakes I found on a pre-filter screen about 900 miles ago. None were present at the last change 400 miles ago, so I wrote it off as no biggie. I have been religious with the Amsoil 20w50 every 500 miles and a new filter every 1000. I ride it hard, but I certainly don't beat on it. I'm gonna drop the oil, do a valve check, and drain the tank tomorrow.

Think it could just be bad gas?

Check you motor mounts. It could just be a coincidence that you just filled it up with gas. Bad gas would cause it to run rough or spark knock but not vibrate.

Mounts were snug. I didn't put a torque wrench on them, but they were definitely not loose.

I've been reading many posts about fuel and it does seem likely that gas can go 'bad' or what ever term you want to use from most any station ... I'd be interested n knowing if changing the gas to another batch fixes the issue ....

I have another idea, check your wheel bearings. Put the bike on stand and shake the wheels from side to side and see if they wiggle.

Well...we are on to the next problem. I figured I do a valve check, and check all the filters while I was at it. When trying to the thread the forward bolt for the big pre-filter back in, somehow it started to cross thread and it snagged on the helicoil. Then while trying to thread the bolt back out, out comes the leading edge of the helicoil. Now I either need to find a replacement helicoil, or thread a bigger bolt, and hope the aluminum holds up.

Time-sert, George at Up-tite fixed my SM610 that way and they are the best way to do it. Check and see if a local shop can help, they are an expensive kit.

Yup...Halls recommended Wurth. That is what they use, and said they were better than new when done correctly. I'm gonna walk to my auto mechanic, and see if he has done them before. The prospect of screwing it up doesn't appeal to me right now. My other option is Wagner Motorsports, but they are a haul.

Did the time-sert. Easy as pie. The source of the annoying rattle has been identified. It was not a gas issue, but rather a coincidence. The rattle was the lower bolt bung for the stock muffler heat shield breaking loose (apparently right after filling up ). This allowed the shield to "flop/vibe"




Looks like exhaust has been blowing by for a while now.