Throotle Body Time

80CX100 wrote:

...
I disconnected the stepper motor & capped off the air box that afternoon;what a difference.

I love the feeling of working through the gears with the throttle & engine;I hadn't realized how much that hanging idle changed the character of the bike;much smoother gear changes both up & down, & I love having 100% of available engine braking power back.
...

Yep, that is what I did a few years ago. Never had a problem with high idle again. Bike starts up no problem, even when cold (min. 5 degr C), although I admit that (like 80CX100) I am always there to help it if needed during its first minute or so.

The early Steppers with the metal body are certainly more problematic than the plastic bodied ones. No idea why? While I never had an issue with my 1100 when I had it my 1200 had a metal stepper on its first set of TB's and it occasionally played up a bit. Just before the motor died though one of the linkage rod ball joints gave up the ghost so when I did the motor swap it got the TB's off the wreck the motor came from and they had a plastic stepper. Never had a problem with that.

07 GRiSO of my friend had his puke after 1 yr, he used the petcock valve in air line with rest disconnected for over 14yrs.
To start cold crack the valve, manual stepper.

Hi,

Today I made the cold start trial.
It was 13ºC outside and the bike was parked overnight. I gave it a bit of gas as I started it, and after the engine fired up I left her alone. She was able to hang on idle, even if a bit shaky with 1000 rpm.

I did then the stepper cleaning.
I started the engine and gave several shots of carb cleaner down the airbox-stepper hose with the bike idling and GuzziDiag stepper test running. It had to bee small shots, otherwise the engine would stall.

Afterwards I connected the hose again to the airbox and took the bike for a spin (~20 km).
In the beggining I had the feeling that the hang on high idle and engine brake had improved, but in the return I catched some traffic and it seemed the hang on idle was coming back again... The hot start (cold start is normal) kept having that initial idle rise.

I plugged the stepper again and I will ride the bike like that for a while to see how we get along....

Question: The stepper function is only to regulate the idle or does it affect the whole range?

Idle only.

beetle wrote:

Idle only.

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Hi, I saw this in some thread, but I can't find it anymore...
What shall be the diameter of the spigots for the petcock vlave to cut out the stepper, 6mm, 8 mm?...
Thanks

Hi guys,

I just want to give you an update on the sitaution.
I've been riding the GRiSO with the stepper plugged, and it couldn't be better...
No pops no fahrts, no hanging on high idle, smoth throotle at slow speeds, doing 240km from full to reserve, idling at 1.000 rpm right after starting cold and at 1200 when hot.
I have ordered, anyway, a petcock valve and I will installed it, just in case the conditions change (now I have clean and balanced TBs), or I take the bike somewhere where the temperatures are really cold. But I f it would be allways like it is now I wouldn't need the stepper at all.

I take the opportunity to wish you all a very happy Christmas together with your loved ones and your Grisos.