MV Agusta Forum banner

1 - 20 of 82 Posts

·
Registered
Joined
·
31 Posts
Discussion Starter #1 (Edited)
Idle and surgeing problem has developed.

Hi all,
I went for a nice long ride of approx 1200km the other week with no dramas for 3/4 or the ride until I was 80km down the road from my last small town fuel stop, Kalbarri in Western Austrailia. Pulled over for a rest and look at the pink lakes for 15min. When I started her again the idle was a little bit rough. This continued for the remainder of the run down to Perth with two more for fuel. Seems to have developed a small amount surging while cruising at 110 4000ish rpm too. The only mods are a bmc air filter, airbox snorkles removed and that exhaust valve disconnected. I am running some injector cleaner through her at the moment but thought I put it out there in case Im missing something.
Bike is a 2012 1090rr.
Thanks in advance for any advice
 

·
Registered
Joined
·
465 Posts
How many miles on the bike? Do you think that you might be pass due on the fuel filter and plugs?

Those minor mods you did will sometime cause issues like running lean or flat spots etc. , if not tuned afterward. But if everything was fine beforehand, I wouldn't expect any of that to be the problem.
 

·
Super Moderator
Joined
·
22,313 Posts
Since the issue developed during a ride, I would be looking for a vacuum leak.
 

·
Super Moderator
Joined
·
22,313 Posts
Visual check first. Look for cracked/missing vacuum lines or caps.
 

·
Administrator
Joined
·
19,805 Posts
Visual check first. Look for cracked/missing vacuum lines or caps.

And after that spraying a flammable aerosol at suspected areas listening for a sharp increase in rpm.....an unlit small propane torch works, too....just be careful.

Also could just be some shite gas....
 

·
Registered
Joined
·
9,955 Posts
Just a thought...You have removed the airbox snorkels. Have you disturbed the air pressure sensor.
On my F4 this is mounted on the left snorkel amd reads the intake air pressure.
On Brutale its mounted in the airbox.
If this sensor is compromised then the ecu wont get correct data and your fuel injection will be too rich or too weak.
Joe
 

·
Registered
Joined
·
823 Posts
Jeff,

Sounds like a coil to me. Check the plugs first but as you changed them at 12000km I don't think so but it's a cheap check. I've dropped a couple of coils in 40000k and symptoms sound similar. Also as Matt M said running a bit lean will also will effect it. I run a Microtec from XBikes and have changed to maps that are too lean and symptoms sound similar. Having done 3/4 of a run with no problems I'd check the coils.

Cheers

Deano
 

·
Registered
Joined
·
3,494 Posts
Noel are you suggesting that we do not ferment our Benzina correctly ,Uhm you might be onto something LOL :highclap:

Worth considering ,step 1

cheers eddy
 

·
Registered
Joined
·
1,557 Posts
I'm with Noel, the last known change is the likely culprit. If the recently got resupplied then a lot of crap could have gotten into your tank. Unless you recently removed the snorkels, changed the air filter, and detached the exhaust valve. On an aside, did you notice a flat spot during acceleration after these were done? Drain the tank through a filter and see if anything is left on it. If it's clean, then likely not the fuel.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #14
Those basic mods had been completed months before with no dramas, so my thinking is they are not the culprit. I just rode home from the airport and notice that the surging/roughness is present while cruising, but under acceleration it seems to disappear. Heading into the shed to start checking vac lines as suggested. Probably on the 3rd or 4th tank of " city fuel " and running injector cleaner through at the moment as
well.
 

·
Registered
Joined
·
5,924 Posts
Surging is not uncommon after making mods related to air or fueling and it may be the surging started co-incidently with the fuel stop. The throttle bodies may need to be synced.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #16
Might have to drop her off at the mechanics to have a look. I've checked the sparkplugs and vacuum lines with no joy. I am time poor with my job, so paying someone with more knowledge than I seems to be the go.
 

·
Registered
Joined
·
1,674 Posts
Make sure they have the diagnostic software, capable of doing a TPS reset, and checking for electrical gremlins.
Over the years, my lack of smooth running issues have been related to a bad connection from the O2 sensor, and a stone getting lodged in the exhaust flap pulley wheel. Both were identified using the software.
I also got a good result when I used the engine tuneup in a can that Mitchy suggested. It is supposed to clean the top end of the motor and injectors etc.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #18
Would I be able to tell if the throttle bodies are out of sync by manually activating them and watching each throttle body or would it be possible for an imperceptible difference to cause dramas?
 

·
Super Moderator
Joined
·
22,313 Posts
Visual would most likely be imperceptible.
 

·
Registered
Joined
·
14,490 Posts
?

Visual would most likely be imperceptible.
Chuck, didn't you watch me do Carl's SPR at Bubba 4?

Jeff,

remove the air box, open the throttles slightly and place a small coin under the right

throttle stop screw .....

now with a NARROW tipped feeler gauge check the 2 right butterflies

now measure the left pair......use the left throttle stop screw the one with the yellow

paint to make the left as close to the right as possible ( I know what the manual says,

but if they could make a good set of TBs we wouldn't be dealing with this bullshit)

now they are mechanically close.....now you need to set the bypass screws

1st check the TB manifold hose clamps .....all tight?

I don't use a set of vacuum gauges or manometer, I use a Uni-Syn, you must plug the 8

stupid holes in the air horns ....

start with the right 2 TBs adjust the bypass screws so the air flow is the same .....

now do the left 2

TPS reset isn't necessary because you didn't touch the right throttle stop screw

simple isn't it?

:popcorn:
 
1 - 20 of 82 Posts
Top