Stepper motor acting up

According to my reading the band-aid fix is to spray it with carb cleaner and cycle it with Guzzi diag. Where exactly should I be spraying?

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It's not obvious, but the hose connected on the lower left side of the airbox closest to the the throttle bodies.

Thanks Mark, is it in the diagram? Here is a grainy photo of what I think is my stepper. [You must be registered and logged in to see this image.]

Hose #4 in the top pic.

Thanks Pete!

No joy on the spray. My comprehensive survey of one '07 GRiSO owner and one '07 Norge owner says to bypass the gizmo. Is there a stepper motor bypass for dummies page? It didn't pop up in my search.

Plug the pipe! I use a short 8mm bolt

If you plug the pipe make sure you plug the spigot on the airbox as well.

If you plug the stepepr, do you have to open up the air bleed valve on the TB to compensate?

No

Plugged hose and airbox spigot. Bike started from cold instantly (cold being relative as it is Summer in NY) instead of chugging and stopping, settled into a nice 1100 RPM idle. I take it cold weather starts are where it will get tricky.

Yes, cold starts could be challenging but it really depends on where your bike idles in the first place. Mine, being a 2V dunger, idles around 1300, so on startup in cold weather puts this around 1100, though it soon rises.

I've had this issue in colder temperatures and a judicious use of the throttle will help until the system can sustain its own idle.

Mine (stepper)has been out of use for the last 6 years with no issues.

I can say that I have not had any problems with starting in winter after disconnecting the stepper -probably around 20,000 miles now; The problem with the stepper motors is the actual motor because cleaning the airways with whatever method you use does not fix the problem.

Not having to adjust air bleeds is one job less too!

BrianD wrote:

I can say that I have not had any problems with starting in winter after disconnecting the stepper -probably around 20,000 miles now; The problem with the stepper motors is the actual motor because cleaning the airways with whatever method you use does not fix the problem.

Not having to adjust air bleeds is one job less too!

No. It may not fix the problem.

As for not having to adjust the air bleeds? How do you work that one out?

Fair comment, It's only that each time I service the bike I check the throttle balance both at high revs and tickover and have not needed to adjust tickover. As I mentioned I have had the stepper disconnected for a long time now.

I'm not sure how relevant this is but I blanked off at the throttle bodies after a year or so after having the link pipes connected to the stepper [main pipe blocked off].

I do wonder sometimes about this as my old Norton had a link pipe on the inlet tracts between the carbs. Think this was for low down torque.

My stepper is acting up as well, leading to high idle when the bike is warm. I've cured the symptoms by adding a valve on the stepper intake hose. However I'd like to try to solve the problem instead of masking its effects.
I have the plastic version of the stepper. Do you know if it's possible to take the motor out of its enclosure to poke at the internals? If so, how is it done? I've seen that there is a slot with a key and I've tried to insert a screwdriver and pull the unit out but to no avail. Is it glued? Do I need to twist before pulling?

There's no "user serviceable parts" inside. If a squirt of goo and an exercise doesn't fix it, it's probably time to replace it.

Or block it

Cha ching.....

BrianD wrote:

I do wonder sometimes about this as my old Norton had a link pipe on the inlet tracts between the carbs. Think this was for low down torque.

@BrianD All of the 1969 onwards twin carb British twins had that pipe linking the manifolds..The manufacturers said this was to "...give more torque".

The mechanics view was that it was to accomodate poor carb synchronisation. All of those twin Amals set ups had separate cables (sometimes all the way back to the handlebars like a LeMans!). This meant that handlebar movement and road vibration moved the cables separately and ruined carburetor synchronisation in about 200 miles .

That balance pipe masked the poor pick up and stutter that ocurred as the slides drifted in and out of synch


The partial cure we used on the racing Boyer Triumphs was to run a single cable to a splitter just above the carbs and tie all components to the frame - this also helps on 850 Guzziz.

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Oz1200Guzzi wrote:

Or block it

Like I said, it is blocked already. But since carb cleaner and cycling didn't do the trick, I guess it's toasted. New ones are really expensive so I thought if its dead anyway, why not take it apart and see if there is anything I can do but I could not open it and did not want to break the shell by using force.  I've repaired steppers with dead coils before so could have given it a try

It's not blocked but only partially working - like it sticks open giving high idle - this bleeds air into the throttle bodies. Put your finger over the hose while the engine is running and you will see what I mean. Block it and your high idle goes away.

Sorry if I was not clear. I have a valve installed. If I close it, the high idle goes away. This is what I called curing the symptoms. Now  I would prefer to have the stepper working as intended since fiddling with the valve on cold days to avoid a low and lumpy idle is sub optimal. Since my stepper seems toasted anyway, I wanted to see if I could try to repair it. I've nothing to loose. If I can't repair I'll just keep the valve on but I might get it to work again.. But from the comments, it seems that it can't be open easily.

My apologies, it was I who misunderstood you. Valve is good. Stepper kaput!