Crazy Idle and Stumble solved...

sschering · Posted: April 22, 2009, 11:42 am Post subject: Crazy Idle and Stumble solved...

Over the last few months I've had this weird problem where the Idle would hang at 2k after the bike warmed up. Let out a little clutch to load it a bit and it'll come back and act normal.. Or it would just randomly die while idling after it's warm.. getting harder to start.. gained a new mid range stumble..
I though for sure I was going to end up pulling the carbs this weekend..

When I got home yesterday I was just sitting there looking at the bike thinking about how I really don't want to pull the carbs because then I'll have to clean the bench to work on em. That means putting all the tools away.. Before ya know it I've got a 2 day project on my hands.

It's about this point I noticed something odd.. a bolt laying on the engine stuck between the starter cover the the cylinder's.. Where did that come from? Hmm looks just like this one here that bolts the carb holders to the head. Well the outside ones are there. A quick peak between the carbs confirms it. One of the inside bolts is missing and the bolt for the other carb is sticking out about a 1/2"..

Well yeah that looks like a problem there..
After letting it cool off I managed to get the bolts finger tight and snugged em up with a stubby hex key.. (yes it can be done with the carbs on)

It's running so much better now!!!

What's my point.. Check your bolts and never trust a PO's work.
PO had replaced the holders.

penn71911

YUP, yup, and yup... first off, these things will vibrate ANYTHING loose... second, I'm a mechanic by trade... (today at least.. you hiring?)... my rule number one is... start at the basics no matter what the last guy that worked on it said... check everything...

Good thing here is... if you HAD decided to pull the carbs, you would have found it anyways.

xjwmx

penn71911 wrote:

these things will vibrate ANYTHING loose...

They will also vibrate wires in two - inside the intact insulation. Two wires to my taillight had that, and one wire in the bundle from the left handlebar still does.

rhilker · Posted: May 7, 2009, 4:22 pm Post subject: Re: Crazy Idle and Stumble solved...

Vibrate? Who would ever have thunk it?

You know your an XS rider if:

" Your girl friend starts the bike in the garage and revs the engine to 10K. "

What Happened to 650rider.com?

Yamaha xs650