bad idle, spit, sputter and popping...hard start

Tunz

hey hows it goin guys? I know this is possibly explained somewhere in one of these topics, but I'm just not sure I could find exactly what I was lookin for.

I've recently been experiencing some problems with my 77 XS650. I just did a few customizations to it, but nothing that should alter its performance drastically. I bought the bike for 1000$ and only drove it the one time to the shop and then started changing a few things. I put a different tank on it, with a somewhat small single petcock. Got rid of the original gauges and put on a small chrome speedo from Mikes XS. Other then that just different fenders and seat.

y problem now is that it seams to start alot harder then it did before the few changes. It also seams to backfire and sorta miss and sputter, especially at lower speeds. Another thing is that it doesnt idle sometimes now. Sometimes it seams to run better then other times...even within one ride.

Just to add...as everyone else says the engine is pretty noisy, I know the valves are loud, could prob use a bit of adjustment, but there seams to maybe be another noise too, possibly cam chain? Especially at a certain rev of each gear there will be a sort of vibration noise, not sure if its engine or somethin else on the bike itself.

anyways, sorry for the ramblin, I've been reading the forums, but not sure exactly how to pin point the problem yet. Any help or ideas would be greatly appreciated.

Cheers - Tunz

pamcopete

Tunz,

Does your model have vacuum petcocks? If so, then perhaps the new tank does not have vacuum petcocks or there is only one of them, so perhaps you left the vacuum barbs open with no vacuum hose connected. That would cause a very lean condiiton and the engine would run like crap and not idle at all.

About the only thing I can think of that would be related to the mods you did.

What Happened to 650rider.com?

Yamaha xs650