Good news!

paulbrice wrote:

I don't think vacuum through the inlet pipe necessarily means the stepper is working properly. Even if it gets stuck in a 'step' position it can still pull vacuum/air. Also when I had the valve on the stepper feed pipe; the engine would stall every time I shut the valve completely and would drop revs as I turned it shut; it also took a period of 'up & down dynamics' before idle settled when I twiddled the valve - presumably stepper/Ecu battling to control it. Within a small range I have set up (only one open) air bleed for minimum idle speed (and not quite exact balance   ) and I haven't had any surging idle issues since.

I don't think fact yours doesn't stall means there is a leak in the system; but probably means the stepper air:bleed air mixture is more oriented to bleed air ie there's enough bleed air alone to maintain an idle. I also think (no basis !) that also makes it more likely for revs to surge as the stepper is more affecting upside of idle air mixture. If you cut back bleed circuit, stepper would have to operate at a different point and may change dynamics.

Thanks, great info! Will see if closing the air balance screw a bit further will have a positive effect (at the cost of balance). Maybe I'm just being overly worried over small things, but I'll be riding from Amsterdam to Naples in 2 weeks and I want the GRiSO to be in top shape for that.

1800km. That’d be a boring trip in two days . I assume you’ll not be taking the direct route on the autostradas?

Pete Roper wrote:

1800km. That’d be a boring trip in two days . I assume you’ll not be taking the direct route on the autostradas?

I could do it in two days, but I'd go bankrupt from the speeding tickets that would inevitably find my door. I'm planning 3-4 days for the trip itself. Afraid I will take the autostradas, as not taking them adds around 8-10 hours to the trip, and I need to arrive at a specific date and don't have the luxury of spending almost a week to get there. I'm part of a team excavating at Pompeii. Staying there for a month, then riding from Pompeii to Poitiers in the west of France for the second project, a Neanderthal excavation in an abri (rock shelter).

Fascinating Tim, that would be a most rewarding trip indeed.

GHTE wrote:

Fascinating Tim, that would be a most rewarding trip indeed.

If the GRiSO doesn't break down!

Why should she?

I do easy 2 days to Mandello thats 1100km from home so 4 days should be fine to Naples. No autostrada
First day to Bodensee, second day to Mandello. Third day to Perugia

paulbrice wrote:

I don't think vacuum through the inlet pipe necessarily means the stepper is working properly. Even if it gets stuck in a 'step' position it can still pull vacuum/air. Also when I had the valve on the stepper feed pipe; the engine would stall every time I shut the valve completely and would drop revs as I turned it shut; it also took a period of 'up & down dynamics' before idle settled when I twiddled the valve - presumably stepper/Ecu battling to control it. Within a small range I have set up (only one open) air bleed for minimum idle speed (and not quite exact balance   ) and I haven't had any surging idle issues since.

I don't think fact yours doesn't stall means there is a leak in the system; but probably means the stepper air:bleed air mixture is more oriented to bleed air ie there's enough bleed air alone to maintain an idle. I also think (no basis !) that also makes it more likely for revs to surge as the stepper is more affecting upside of idle air mixture. If you cut back bleed circuit, stepper would have to operate at a different point and may change dynamics.

Thanks, I did this and now the idle is as it should be. Balance is slightly off now (24.5 vs 26), but this doesn't seem to have any noticeable effect.
I also think, but this is rather subjective, that the left cylinder now runs less hot than before. I noticed several times last week that my left knee got very warm (barely tolerable) from the heat from the left cylinder, though this could also have to do with other factors like wind direction/slightly shifted riding position/more stop and go traffic.

2highlander wrote:

Why should she?

My GRiSO likes to throw small issues at me to keep me on my toes. Essentially roughly once a month I'm either fixing something or investigating some newly developed odd behavior or sound. It's almost like a wife.