Help!

[harp]

Hey Guys, I have a 1980 XS650 special. I recently got this bike and have taken it for a few fun rides. Recently the bike started running a little weird and the plugs looked lean in the right cylinder and rich in the left but the bike seemed to idle fine. I went ahead and did an oil change tonight and now the bike won’t really idle and it’s leaking from the oil filter. More concerning is the fact that it is now making a sort of rattling noise. Did I somehow fuck up an oil change? What steps should I take next to figure out wtf is going on and how I can fix it? Thanks!

 

[Niels B]

Could be a bunch of reasons - but I doubt it’s anything to do with your oil change.
How long had the bike been sitting prior you start running it?
If it had been sitting for a long while I would have gone through a few basic
Drain tank, check fuel filters not in tank and any external filters, drained carbs and cleaned same, check plugs and oil filter ( cleaned filters) check cam chain tension, ignition timing and valve adjustment.
Where does it rattle from ? Could it be you cam chain or valves ?

 

[harp]

I rode the bike to the store to get the oil and rode it yesterday as well. But before that it sat for a little over a week while I was out of town. The noise sounds like it’s coming from the top end. I got a video i’m not sure how well u can tell tho.

 

[Jan_P]

With the wrong carburetor setup it can sound terrible ..So after checking oil and lubrication I would focus on getting the plugs look even
Cleaning the tank and so.

 

[nj1639]

New to you bike.
There's a thread in the Tech section about that.......things to go over.
Like mentioned above, sounds fuel related.
Ignition is TCI for '80 and newer, unless it's been changed, and they're pretty reliable as a 'plug and play'.
Go through the fuel system and see where you get.
Sitting for a week or so is nothing to these.

 

[Adamc]

Good luck with your build.

Its a rare thing but I did have an issue with my TCI on my 1980 XS650.
After weeks of trying to solve a poor running miss-fire the TCI was the last thing for me to look at.
In the end the TCI igniter box was the issue. I solved it with a Suzuki GN250 'Gonzo' fix with the help and advice of the members here.
More of that here: https://www.xs650.com/threads/welsh-flat-track-revival.60449/page-11
From #216

The consensus here is to look thoroughly at ignition systems first then move on to fuel supply.
Cheers
Adam.