Subject: Stepper motor shutoff Sat Apr 14, 2018 3:41 am
For any of you that have done the in line shutoff to the stepper motor, what kind of valve did you use? All I've been able to find in a small valve is 1/4" fuel shutoffs for lawn mowers, any suggestions on something for the 3/8" of the hose?
goozy Squinternotto
Posts : 1 Join date : 2014-04-09
Subject: Re: Stepper motor shutoff Sat Apr 14, 2018 5:50 pm
I found a direct fit at my local NAPA a few years ago. Black plastic body red plastic knob. Looks factory.
GuzziSteve Fra Cristoforo
Posts : 772 Join date : 2016-04-14
Subject: Re: Stepper motor shutoff Sat Apr 14, 2018 9:50 pm
A dirt bike aftermarket fuel valve is what I've installed.
It fits the original piping on one side & I bought some extra pipe so it sat conveniently.....sad to say it has been useless and I recently removed it. I don't think the stepper issue is repeatable enough to use the tap as a quick fix & would have to re-balance the air bleed if you used it permanently
I ended up using the exact same one. My confusion was coming from the fact that the hose is 3/8 from sitting on the airbox nipple and expanding, but elsewhere is actually 1/4. I like to assemble parts for a project before I start it, but sometimes you don't see the whole picture until you start cutting
Subject: Re: Stepper motor shutoff Tue Apr 17, 2018 3:38 am
Has this made a big difference for those of you that abandoned the stepper? I haven't had a chance to get out and test thoroughly after installing the shutoff, but I'd like to know if it got rid of some of the snatch when warm and the high idle problem?
Oz1200Guzzi Don Abbondio
Posts : 6081 Join date : 2014-03-13 Age : 69
Subject: Re: Stepper motor shutoff Tue Apr 17, 2018 5:51 am
High idle is fixed for sure. Snatchiness is between throttle cable adjustment and a good map.
paulbrice GRiSO Capo
Posts : 1481 Join date : 2015-01-04 Age : 63
Subject: Re: Stepper motor shutoff Tue Apr 17, 2018 9:23 am
Agree it's just for high idle but it didn't work at all for me. Engine won't idle with the valve shut completely & trying to balance random high idle problem out by partial twiddling valve sitting in traffic was PITA easier solved by blipping throttle or just waiting for it to set down.....I can imagine (cos I've been too lazy to check) you could shut it in and open the air bleed a bit to stabilise idle IF the actual cause is the stepper itself
I just pull & clean the TB assembly when it gets really bad which isn't often.
I fitted a pneumatic valve on my 1200 Sports (2V) x3 to fix high idle. As soon as the engine gets up to temperature, the stepper motor is switched out of circuit. The increase in engine braking is enough reason to do this.
But the idle on my GRiSO 1200SE is fine, so what's not broke I don't fix.
Subject: Stepper motor shutoff 
Sat Apr 14, 2018 3:41 am
