Rough idle after attempting tune up

Technical All CARC models
1

Hi, I serviced the new Griso 1200 , 2010 a few day’s ago plugs oils filters did the valve clearences etc, fired up sounded and run great. As I was planning to use the beetle map after lot’s of research and videos I attempted to. Balance the throttle bodys as per requirement and check tps. But when setting up for it everything was fine until I nipped up both the air bleed screws, the were both open and unfortunately I didn’t count the turns as it wasn’t mentioned. But as soon as I fired up its was really lumpy and cut out at one point. I managed to balance at 4000 revs but it was still rough. After checking the tps it registered 4.5

The procedure required firing back up then opening the side with the highest pressure to balance idle but it didn’t seem to make much difference. I’m suspecting something isn’t right but I don’t know how to get back what settings the air screws were set to ? Any advice appreciated. I made sure btw I didn’t mess with the sacred screw but worried now it might have been done before?

2

If it ain’t broke…

Ouch! Sorry for your troubles but curious were you trying to address a specific problem?

I am no eggspurt but is it not possible to simply try reopening the air screws little by little to see if you get back to normal running? If that is a dumb suggestion apologies. Good luck!

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Yeah I wish now I hadn’t of messed but it was a little jumpy at low revs and from all the information id gathered a service and TB balance and beetlmap is the way to go but even following step by step no one seems to mention rough running when screwing the air screws in which makes me think mine had been set up to kind of mask a problem, I will attempt again when I have a new manometer which is to rule out any issues with my old one but the puzzling thing is the problem started before adjusting the pressures, it was bad as soon as the air screws were closed?

4

Mmm you are now into some deep Voodoo or deep DooDoo. Way above my cerebral grade but surely one of our wizzo Guzzi tuners will chime in. Hey it WAS running. How tough can it be?

5

:joy: well, if no joys I’ll be hoping there’s someone not to far from Shropshire who knows Guzzi’s but one of the reasons I bought one was because of there simplicity but maybe I’m finding out the hard way.

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Ahh I think they really do have a reassuring simplicity but there are a few gnarly deep divers into their unique quirks around here. I’m just a parvenu compared to these guys. When you get it sorted you will be hooked! :grin:

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think I’m already hooked, she stole my heart at the first look, she’s already raided my wallet, I’m doomed

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Nigel at NBS is not too far from Shropshire in Staff’s

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Yes thanks for that, Ive got a few things to run through from advice off the Griso ghetto and if that doesn’t work out I’m hoping he can help. At least I made good of the hot weather before the change :joy:

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Air screws on fuel-injected bikes are usually a Don’t Touch! item but we all ignore it. Back them out a short way, then gently screw them back in until they bottom. Now wind them both back out one and a half turns. This will give you a very good rule-of-thumb starting point.

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11

Sorry Dai, but that’s totally wrong.

The Air Bleed Screws are to balance the TBs at Idle, after doing the high-speed (3500-4000rpm) balancing with the Balancing Adjuster.
Both should be closed (lightly) before doing the Balance run.
Then as Sivy rightly said (and did), the one on the TB showing the highest vacuum at idle is opened slowly until the balance is restored.

Idle Speed is governed solely by the Idle Control Valve (ICV, or more commonly referred to as the ‘Stepper’), which is controlled by the ECU.

The Stepper can give problems with Idle Speed if it gets contaminated with Oil from the Airbox.
Oil gets into the Airbox via the Oil Recirculation System.
Ordinarily, not enough Oil gets into the Airbox to cause issues, but if the Oil Level in the sump has been repeatedly (and incorrectly) topped up to the upper mark on the Dipstick, then you will get a lot of Oil in the Airbox.
Some of the Oil will inevitably find it’s way into the ICV, gumming it up, messing up your Idle, and into the TBs, which gums-up the Throttle Plates, also leading to rough running low down.

Correct Oil Level is around midway between the upper and lower marks on the Dipstick.
You should never top up the Oil unless the level reaches the lower mark (never seen it happen on any of the 1200s).
As long as it’s above the lower mark, leave it alone!
When refilling after an Oil change, only fill it to the midway point, it will find it’s own level.

If it’s continually topped up, you may as well be pouring Oil straight into the Airbox.

Check the Airbox for Oil deposits, at the front, Filter removed.
There will always be traces of Oil in there, but that’s all there should be.

Also check your Throttle Plates, inspecting them (and cleaning if necessary) is part of the Maintenance Schedule, but mostly gets overlooked/ignored.
A cheap Boroscope Attachment for Smartphones is very useful, poke it into the Airbox and guide it into the Inlet Trumpets.

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If anyone would like a copy of my ‘Tips List’ for the 1200 Stelvios, just message me.
Tons of useful info for all 1200 owners, due to the shared Engine/Gearbox/Swing-Arm/CARC Unit, etc, across the model range.

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Thanks for the information doc1 , I m suspecting something along those lines due to the reaction when I closed the airlines I’ll run through it again as per Pete’s instructions from the grisoghetto and if it’s still the same he suspects the throttle bodies would have been compromised. I’m hoping it’s something resolvable, I’m not sure how hard it is to get at the throttle bodies, stepper motor etc as there’s not much in the way of videos etc I’m hoping it’s competent diy friendly.

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Mea Culpa. :grin:

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Doc’s advice is spot on but on my one the oil gum was sitting in the air bypass tubes and occasionally blocking them. This made the last stage of throttle tuning - fine tuning the air bypass screws to get an even tickover and clean pick up very very hard

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Johnny , How big job was it for you to clean out the pipes, is it a major strip down and did you do it yourself. Also were the throttle bodies clean inside or did you do the lot thanks

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Its not major. It is awkward. Getting them out (and back) took me 90 mins. the cleaning less then 30 min. If you have not yet taken the fuel tank out it is a job and skill on its own - read the Ghetto and make sure the tank is not full and you have a big flat space nearby to put it on next to the battery.

(1) Tank off - 2nd hardest part. (2) Injectors out and off, (3) Cables and pipes photographed, disconnected and taped out of the way, (4) semi-flexible (!) pipes to airbox out - the worst part - (5) undo the clamps on the inlet adaptors and get the adaptors out of the way. (6) Then you need to roll the injectors 90 degrees-forwards i remember but plz check. Now you can work them out to one side - i cannot remember which right seems sensible because it would clear the starter but i remember the job as being counter intuitive.

My throttle bodies had a black greasy mark along the lower side and dribbling out of the air bypass so i removed the screws and blew the tubes through with a can of carb cleaner.

Reinstall is the opposite of disassembly except

getting the pipes to the airbox on was harder

and getting the tank back in is always a bit easier then getting it out.

Hope that helps

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Thanks Johnny, appreciate it. I’ve just bought an endoscope for my phone so I’ll send it down the airbox and see if I can see the condition of the bodies from there, I’m not sure how it’ll pan out but may give me some insight. I’m giving the rebalance another go today so if that doesn’t sort it, I’ll have to plan the next steps, cheers

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19

You “da man” getting wired in to it all. Despite trickery I think you are enjoying yerself? :grinning_face_with_smiling_eyes: Hope you get her sorted the way you want! :+1:

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Okay thanks for the replies I think ive cracked it, so ive set valve clearences, full service plugs, engine oil gearbox and carc, new air filter rebalanced the throttle bodies and reset tps and learning. When doing the idle I noticed the stepper motor pipe had pulled off on the right side so I’m guessing that prevented me from sorting the idle, must have come away when I was pulling the little plastic trim off the tank :thinking: anyway balanced idle and uploaded the beetle map and noticed a definate improvement on the idle throttle response, it doesn’t seem to splutter a little like it did and picks up nicely. I haven’t been out yet so need to see how slow riding is but pleased so far.

Now for the next job, it intermittently just clicks when trying to start, if I turn off then back on it starts. I think the click is coming from the right hand side by the air filter. I cleaned the battery terminals no difference, I then cleaned up the earth connection down by the starter motor which temporarily seemed to make it worse, what is confusing is it seems that I had to press the kill switch then start a few times before it fired. I’m not sure if it’s a dogey connection in the switch or the usual startus interruptus which ive bought wires and connectors for if it is. I know there’s a lot of info as it seems a common problem. What joy :blush:

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