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Stepper motor on/off kit

GT-Rx said:
capdefra said:
is the Stepper motor on/off kit also available for a Stelvio ; mine is a Stelvio NTX 2009.
Click to expand...
Franck, sure is, I'd recommend the Griso/Sport version unless you have a place you'd rather mount the switch. If you have any other questions, ping me direct e-mail; Todd at GuzziTech.com
Click to expand...

Thanks Todd. My Stelvio NTX as only 1600 kms and have no problems with the stepper motor and iddle but I had before a Norge which had erratic iddle because of the stepper motor. So I consider your kit as a good solution for my Stelvio if I have problems like the Norge.

Franck
 
The small holes in diaphragm inside the valve allow the rubber plunger to open and close with delay/bleed. It is not the orifice in which the air travels.
Click to expand...
Thanks for your answer, theoretical I can understand it, but in practice it won't work this way. . . although at my bike. . . I can feel sort of a second step, but still the airflow is minimal.
This morning I removed the airbox for the third time (I'm getting quicker every time), and it works the same as the first time I installed it: the bike won't idle at all. I have to raise it by hand to keep the engine turning. A small testride tells the same: it makes no difference if the switch is on or off, the engine runs the same. That means no popping at all, while formerly he was popping terrible.
Formerly the bike was starting perfect, so I think only thing is to look for a valve that opens fully for starting the bike properly.
 
The open/on valve should allow a 1500 RPM idle. If you add 12V, you should be able to blow through the valve, not like blowing through an open hose though. If you add power and find this not to be the case, I can send you a new one or refund you my cost of the valve. I tested numerous valves and selected this one because of function and cost. There are other valves out there, but as you'll likely find, the cost of each far exceeds the whole kit.
 
It is not model specific. All the big CARC bikes use the same basic stepper motor set up. Only the details like hose routing and switch are different. The stepper motor takes filtered air from the air box and bleeds it into the intake tract when the throttles are closed. This helps maintain a stable idle when cold but it is also used to reduce emissions on decel. That is why it messes with your engine braking. By blocking off the air passages you can prevent the stepper motor from doing this. But since the bike may not want to idle when cold with out it being able to turn it on and off is key. Todds kit does this nicely with a solenoid valve and a switch (but he may be out of the handle bar mounted switches) or you can do it with a manual switch.
You can even block off the stepper motor with some plugs to see what it will change before you go whole hog with this mod.
 
Right, fitted the kit. Even with my meagre skills I worked it out. It's hard to find a suitable place for the valve on the Griso, thats for sure! I got it sorted though.

I haven't run it hot yet, will test ride it a little later. Here are a few initial observations:

1. I didnt have an erratic tickover before, as I have said, I have fitted it so I can get my engine braking back. However with the valve now fitted it IS erratic with the valve open.

2. Close the valve, idle drops but is steady. Bike takes a little longer to warm up before it'll settle like that.

These I expected. However:

3. When I switch off the bike, the fuel pump seems to run a moment after the engine is switched off. This happens whether the valve is open or closed. Is this normal?

Edit:
I'm not sure if its the fuel pump now. But something whirrrs for a few seconds after the motor is stopped.
 
GuzziHero said:
When I switch off the bike, the fuel pump seems to run a moment after the engine is switched off. This happens whether the valve is open or closed. Is this normal?
Edit:
I'm not sure if its the fuel pump now. But something whirrrs for a few seconds after the motor is stopped.
Click to expand...
Completely normal, and completely unrelated to the stepper motor.
 
Just fitted a stepper motor cut out to my Norge 2 valve.
I have two issues if anyone can help
(1) With the switch in the start position, ie stepper motor in the standard (start) position the bike will not start as it used to, that being, hit the starter and the bike used to start and tickover after turning over a couple of times without touching the throttle
Now I have to start it and keep the thottle open and hold it so that it doesn't stall, if I don't it will not fire up.
After the bike has warmed up around 20 miles and I move the switch over to the run position the bike ticks over at 800 rpm.which is fine and I have also lost the backfiring on deceleration.
(2) The mpg has dropped from 42 mpg to 36 mpg which is abit annoying.
Are both of these things normal and if not, what can be done to rectify it
Cheer Phill
 
Phill, this is one of mine? Sounds like your stepper motor may not be working. Do you have any error codes? Fuel consumption seems very abnormal as well.
 
Yep It's one of your units.
The revs drop down slightly to about 700rpm when the unit is switched so I think the unit is working.
It just doesn't hold a fast tickover when its cold without holding the throttle, and when it is warm enough to tick over it suddenly misfires about every 5th stroke and trys to die.
I've checked and there are no faults stored.
I will go to a local dealer and get the TPS reset and see if that makes a difference.
I'll let you know what happens.
Cheers
Phill
 
Phill, the engine is programmed to idle 1250 RPM, so ~700 is very low. I'd suggest a TPS check/reset for sure.
 
maverick9611 said:
is this kit still being made?
didn’t see one in the store
Click to expand...
No it isn't. I just made my own. I removed the hose from the air box and ran it down near the rear brake lever. First I used a bolt to open and close the end of the hose. Open to start cold and then plugged when warmed up. Now I'm fitting a fuel shut off valve to make opening and closing the hose easier. Somebody else did this quite a while back and I used their idea. If you search there is a thread about it all.
All popping below 4,000 rpm has been eliminated when down shifting. The bike sounds and runs great. PC5 and AT300 of course helps immensely.
 
I've long planned to fit a little 12V solenoid valve, operated by a button on the dash, but never quite figured it out. I believe Todd/GT briefly offered such a kit, anyone have any details?
 
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