Idling problem

[MikeBenzon]

I just finished a valve adjustment job and now my bike is dieing at intersections when the motor is fully warmed up. When I start it, it idles fine. When I was performing the TB synchronization, I had to move the stepper motor out of the way, it seperated into two pieces. I put it back together and remounted it in it's place, coud I have damaged or dropped something out of the stepper motor? Any other ideas what might be the problem?

[The Kurgan]

You could have a crack or break in one of the stepper motor hoses. Even a small crack can cause idling problems.

[Bixxer Bob]

The stepper motor is a fairly robust piece of kit so it's unlikely to have come to harm, as long as the white round bit wasn't binding in the body at all - it's a very snug fit but should have lined up ok.

As K says, a hose leak will spoil the tickover, so make sure there's no leaks where you pushed the hoses back on after the balancing.

[Stretch]

While it's apart, make sure that the Stepper Motor and Idle Valve are nice and clean inside, and that the o-ring is in good condition.

[MikeBenzon]

Thanks everyone for the advice. So everyone is mostly sure it is the stepper motor? Makes sense, since it controls the idle and that's what isn't working so well.
Thanks again.

[Stretch]

Check the hoses first.

[The Kurgan]

While it's apart, make sure that the Stepper Motor and Idle Valve are nice and clean inside, and that the o-ring is in good condition.

Speaking of the o-ring... I noticed mine never had one when I went in to check things and clean the stepper motor. I recognize that the parts fiche show's one. Should I be worried?

I was very careful when I disassembled the stepper motor housing.

Mine seems to be idling fine without an o-ring.

I wonder if I should order one just in case?

[The Kurgan]

See schematic below. Part #2

I also bought a spare stepper motor a while ago as I have this obsession with having spare parts that are known to give up the ghost early on Tigers "just in case".

That spare stepper assembly came off a 2005 Speed Four. The exact same part. It also didn't have an o-ring. I wonder why

[The Kurgan]

While it's apart, make sure that the Stepper Motor and Idle Valve are nice and clean inside, and that the o-ring is in good condition.

[MikeBenzon]

I stripped the bike down to the stepper motor again today and removed it. It was dirty, so I cleaned it up. A little problem occured. As I was carrying the unit to my work table, it came apart with the plunger, spring and a spring cup went flying. Luckly I found them all and cleaned everything with WD40. I didn't see how them came apart so I guessed at how to put it back together. I placed the spring cup on the bottom end of the spring, I hope that is right.
I also learned how the stepper motor works, I think. At first I thought the stepper motor was a solenoid that pushed the plunger up and down, wrong I think. It is a motor that turns around the threaded shaft attached to the plunger that raises and lowers the plunger. When the ignition is turned on the stepper motor runs the plunger up to the top to calibrate and then lowers it to the proper level to allow air to the throttle bodies. Am I correct?
I am concerned that I may have damaged the unit when I forced the plunger down to pull the two stepper motor halves together while bolting it back on its mount.
I put everything back together and took it for a test ride. It idled properly at all the stops with one exception. I stopped to chat with someone and turned the bike off. When I restarted it, it didn't want to idle until I revved the motor a couple of times. Then it ran properly.
Tomorrow I will take it for another test ride and if there is any sign that it has a problem, I will oder another stepper motor.
All the hoses were properly fitted, so I am sure there are no leaks.

[The Kurgan]

Not sure about your stepper. It is easy to figure out what goes where, so I am guessing you assembled things correctly.

As for the hoses, a visual check is not always enough.

I would disconnect each hose, plug one end with your finger (to create a seal) and blow into them. You will know if you have any leaks. And don't worry, nobody will think you have some strange hippie smoker contraption thingy!  :D

[Sin_Tiger]

Yup, that's how all idle / emmisions control etc. stepper motors I have ever come accross work, bikes or cars.

Not a whole lot that goes wrong with them, either stick or don't seat properly.

[EvilBetty]

I also bought a spare stepper motor a while ago as I have this obsession with having spare parts that are known to give up the ghost early on Tigers "just in case".

Huh?  This is the first thread I've ever noticed involving the stepper motor.

I'm getting ready to do a TB balance.  I better go find that "how to" again!

[The Kurgan]

I also bought a spare stepper motor a while ago as I have this obsession with having spare parts that are known to give up the ghost early on Tigers "just in case".

Huh?  This is the first thread I've ever noticed involving the stepper motor.

I'm getting ready to do a TB balance.  I better go find that "how to" again!

I wouldn't call it common, and its certainly not just a Tiger issue, but I have read quite a few reports on the "other" forum of marginal stepper motors on a variety of Hinckley models -- most of which share the same stepper as ours. I just felt it safe to have a spare.

[Bruincounselor]

IMHO the o-ring is not optional - especially if you are riding in dusty conditions. Without it you will be running unfiltered air into the engine.

I know of one instance where this led to the destruction of a Girly (not mine). It is back on the road with new pistons, sleeves and rings.