2012 Norge Gt stalling/sputtering off idle below 2000 rpm

[mrv]

My Norge has been a reliable bike since I performed the roller conversion on it after I bought it. I started riding to work again last week since the weather is warming up. It was running great as always, I fueled up on the way home (91 octane ethanol-free) and rode the next day with no issues. But the day after that I took off to work and the bike sputtered and stalled when pulling away from a stop. The bike fired right back up, and I had to work the throttle a bit to get it above 2000 to be able to take off. It continued with the issue the rest of the way to work and back that day. It is mainly noticeable when pulling away from a stop, but it does have a stumble when I crack the throttle wide open at upper rpms as well. I thought maybe I got bad gas, but when I opened the fuel cap the tank had pressure, I checked the vent lines and they were clear, I drained and replaced the fuel, added fuel system cleaner, and checked the air filter to eliminate the obvious possible issues. I do not have a diagnostic tool to connect to the bike, there is one code for the instrument panel 5M. I have done a bit of searching but I feel it is faster to get directed to the right thread if there is one by asking a question.

[NWrider]

Possible water in the fuel.   I had similar issues with an SPIII.   When I finally removed the tank, I found about 4 oz. of water.  No problems after I refilled the tank.  Adding some alcohol fuel treatment should absorb water.   Might be worth a try.

[Wayne Orwig]

TPS maybe. Sticking idle control motor maybe.

I would find someone with the diagnostic cable.

[guzzisteve]

Could even be fuel filter getting full. Many posibilities, like Wayne said may be tps reset if not done recently.

[mrv]

If I get the cable and Guzzi Diag, will that enable me to reset the tps?

[Huzo]

If I get the cable and Guzzi Diag, will that enable me to reset the tps?

Yes.
Also you can check for codes while doing the balance.
 Remove and clean the TB’s.
How is the idle ?
I’d be reluctant to blame the stepper as long as it’s idling ok.
I’d give it a fuel filter and plugs, also look at the plug caps, (don’t destroy them upon removal).
Check the valve clearances.
With Guzzidiag, you can look at the TPS trace to see if it’s functioning correctly.

[mrv]

It starts and idles fine, just has that bog when accelerating from idle, and when I crack the throttle hard at higher rpm.

[Tom H]

Check your spark plug caps for arcing. I worked on a bike with a similar issue. Had the spark plug covers off and thought I head a click, turn out the boot was arcing to the head.

You probably need to get it in a dark place or shade the plug are to see it arc.

Just a thought.
Tom

[pehayes]

Similar bog on an SPII.  Turned out to be aged, weak coils.  Might check ALL coil connections.

Patrick Hayes
Fremont CA

[mrv]

I checked this morning and did have arcing from the top of the boot on the left cylinder when I started it. So I'll start there first.