Griso 1100 idle issue

[oranges3]

Griso 1100

My bike will momentarily cut off when coming down to idle.

Slow to return to idle.

Never cuts off with throttle.
Removed stepper hose from airbox and plugged hose... idle gets worse.

Gonna go through the tune procedure again. But if my stepper is knackered, why would it male the idle worse when blocked off when I have seen so many block it off or use a  valve to do so?

Valves were set to .15 and .20.

Throttle body balance, tips reset completed.

[Huzo]

Griso 1100

My bike will momentarily cut off when coming down to idle.

Slow to return to idle.

Never cuts off with throttle.
Removed stepper hose from airbox and plugged hose... idle gets worse.

Gonna go through the tune procedure again. But if my stepper is knackered, why would it male the idle worse when blocked off when I have seen so many block it off or use a  valve to do so?

Valves were set to .15 and .20.

Throttle body balance, tips reset completed.

Is yours 2 valves per cylinder or 4 ?
What does “cut off” mean ?

[guzzi ride]

It's definitely a 2 valve. That's all I got.

[Bulldog9]

Is yours 2 valves per cylinder or 4 ?
What does “cut off” mean ?

Huzo - 1100 always = 4 valve motor (2 valve head) on a Griso

OP, did this problem start suddenly? Same issue when hot and cold?


Sounds like it started after a TB balance.  I'd go over it again and start with both air bleeds closed. When doing the balance did you use the screw on the bellcrank or the stop screw on the TB? I hope it was just the bellcrank.

If you had the airbox off, make sure the boots are firmly seated on the TB's and tight. It might be getting too much air and is messing up the idle. Stepper may be gummed up and slow to adjust. Some have sprayed silicone spray into the stepper line to loosen things up. I squirt a tablespoon of seafoam into mine every year or so during a deep clean or strip down.

I have the opposite issue on my 1200 Sport, the stepper hangs with a high idle.

If you have Guzzi diag, there is a stepper motor test that will cycle the stepper motor to see if it is working.

FWIW, I run my Griso and 1200 Sport at .10 & .15. per recommendation from Roper & Beetle. Likely not your issue.

[guzzisteve]

Is yours 2 valves per cylinder or 4 ?
What does “cut off” mean ?

Huzo ,      He needs your thread on Steppers.  I think you did extensive research or another here.

[Huzo]

Huzo ,      He needs your thread on Steppers.  I think you did extensive research or another here.

I didn’t do much with steppers, more so throttle body sacred screw recovery.

[not-fishing]

How many miles?  I began having problems because of a partially blocked fuel filter at 45,000 miles.

[oranges3]

How many miles?  I began having problems because of a partially blocked fuel filter at 45,000 miles.

Fuel filter replaced 1k miles ago.

[oranges3]

Huzo - 1100 always = 4 valve motor (2 valve head) on a Griso

OP, did this problem start suddenly? Same issue when hot and cold?


Sounds like it started after a TB balance.  I'd go over it again and start with both air bleeds closed. When doing the balance did you use the screw on the bellcrank or the stop screw on the TB? I hope it was just the bellcrank.

If you had the airbox off, make sure the boots are firmly seated on the TB's and tight. It might be getting too much air and is messing up the idle. Stepper may be gummed up and slow to adjust. Some have sprayed silicone spray into the stepper line to loosen things up. I squirt a tablespoon of seafoam into mine every year or so during a deep clean or strip down.

I have the opposite issue on my 1200 Sport, the stepper hangs with a high idle.

If you have Guzzi diag, there is a stepper motor test that will cycle the stepper motor to see if it is working.

FWIW, I run my Griso and 1200 Sport at .10 & .15. per recommendation from Roper & Beetle. Likely not your issue.

Took the stepper off and cleaned the crap out of it.
Hoses from stepper to throttle bodies were loose so they got replaced.
Definitely made the idle better but would drop and momentarily cut out when throttle returned to idle.

So I got a Twinmax carb balancer and meticulously set the balance at 4000 rpm with the adjuster on the lh side.
Reset the tps and learning parameters,  then set idle balance using the lh air screw.

Bam... all good!

Starts very easy just like it used to... and comes back to idle like it should with no drama.

[Huzo]

You bloody beauty…!
Feels good doesn’t it ?

[guzzisteve]

I had no doubt you would find the issue looking at everything. Loose hoses, 15yrs old, not a bad idea to swap out. If stepper keeps going use it. I used a twinmax, nice if you don't get it too sensitive.  Way to go make it reliable.

[oranges3]

Issue came back

Before I did the following the bike ran great
Replaced the sump gaskets
Replaced the oring on the timing sensor
Replaced the alternator belt
Adjusted valves to. .004 and .006
Tried to start the bike... just kept turning over and no start
Replaced the oversized oring I used on the timing sensor with a smaller one that would fit in the channel.

Bike will start and run. But when the engine comes back to idle it drops off and fhen recovers.

I set the throttle screw... not the scared screw... at. 4k rpms , reset tps and learning parameters,  and the idle using one air screw as directed by fhe twinmax.

Replaced the stepper motor with a used one.

Cleaned throttle bodies... still no joy.

What am I missing?

[Huzo]

Check the integrity of the ball joints n each end of the crossover link.
If they are free to rattle around, every time you do a TB balance it will go out of adjustment almost immediately.
TPS not loose on it’s base ?
Comes back promptly when turned ?
Injector electrical connections ok ?
All plugs/connectors to them ok?
Any codes thrown ?

[oranges3]

In case anyone cares...
My timing sensor was removed to fix a leak and was reassembled as it was.

That's when my problems started.
Removed the thinnest of the 3 shims used on the sensor.

Problem GONE!

Starts easy. stepper motor works, no stalls on 30 min ride.
Idles perfect.

[Huzo]

In case anyone cares...

I do…
Well done.

[Bulldog9]

In case anyone cares...
My timing sensor was removed to fix a leak and was reassembled as it was.

That's when my problems started.
Removed the thinnest of the 3 shims used on the sensor.

Problem GONE!

Starts easy. stepper motor works, no stalls on 30 min ride.
Idles perfect.

Great news!