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Discussion Starter #1
So im well on my hunt for fixing the lurching/jerky throttle and feel like the throttle bodies are sticky. Is there a way to lube/clean these(without too much involvment)? Meaning seafoam or running some sort of cleaner through gas, lubing everything in and around? And yes i know that tps adjustment may help along with retune/ecu etc...just put a throttle tamer on/removed one throttle spring too.
 

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It might help if you update your profile so we know what bike you have.

It looks like you have all the usual suspect areas covered. The next step will be spending $ on remapping if you are using the bike in city traffic and need the low rpm throttle control.
 

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Are you sure it's the throttle body's sticking.
A common fault is the bar end jamming the throttle tube.You just need to move the bar end out a little.
 

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Are you sure it's the throttle body's sticking.
A common fault is the bar end jamming the throttle tube.You just need to move the bar end out a little.
What Mitchy said is the first place to start. However the snatchiness in the throttle is inherent in these M.V.'s. The std. ecu is the main culprit. A Microtec goes a long way to smoothing everything out but even with one of these the throttle is still touchy down low. Also the vacuum down low slams the butterflys shut and that's another reason they're hard to ride at commute speeds. I also fitted a Domino racing throttle which smooths things out a bit.

Cheers

Deano
 

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In 2008, the ECU in the 910S Brutale is a the 5SM Magneti Marelli. It is tunable by a qualified tuner. Tuning the low response will smooth out those rough transitions and jerky feelings at and below 4000 rpm.
 

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Discussion Starter #7
Checked the bar end when i put the new throttle tamer on, its good to go. The engine vacuum makes sense and is probably what im feeling. I think i will get a quote from the local MV shop and see what they say regarding tuning, pretty sure they use rapidbike but i got the feeling they are reluctant to tune bikes(they recommended me use throttle tamer when i first asked).
 

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Using an organization that recommends a band-aid fix would not give me confidence.

Contact this guy: Rob's Dyno Service | Bike Tuning | Tuneboy | Gardner, Massachusetts

Tell him Chuck sent oy his way and let him know which bike you have. He should be able to flash a map into the ECU to solve your issues. I can't remember if we mapped a 910S yet or not.
 

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Said he would need the bike to tune but he said his partner who does the same is based out of twin cities which is much closer.
Yes. His partner, Doug, and Rob did a lot of programming for these ECUs. Doug would be closer.
 

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Hi

Check that the throttle butterflies in one or both sections of the throttle body are not jamming against the bore of the throttle body when the throttle is closed.

Also adjust the throttle cables to minimise the free play so that the first few degrees of throttle movement is not just taking up the slack in the cables.

Then check the TPS setting.

Tony
 

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Hi

Check that the throttle butterflies in one or both sections of the throttle body are not jamming against the bore of the throttle body when the throttle is closed.

Tony
The throttles do not close all the way......

:wink2:
 

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This might help ,done all this crap years ago ,They are a pain but when you get it spot on the bike is a joy to ride even down at low rpm .
this is only for 5sm Ecu. http://www.mvagusta.net/forum/20-maintenance-tech-issues-all-4-cyl-models/52716-balance-screw-tb-2.html

Many discussion on this ,you just have to try and find it , I spent thousands of dollars on it and many hours went the Pc5 way and race ecu and Dyno tune , Im happy now . Others went the Microtec way . and Rob's Dyno Service . If you are close to Rob's dyno service that would be the way to go .

Good luck
 

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?

They will do if the stops are not set correctly.

:wink2::wink2:
If the stops are backed off so the throttles close all the way.......
1. a 1st Gen MV won't idle, you can't enough air through the bypasses
2. the TPS is wrong too
3. it will be difficult to open the throttles, the Magneti-Marelli throttle bodies are built backwards.....big side
of the blade is uphill

The set of throttle bodies here on the floor have a blade gap of 0.4mm

Here are the tools I use to sync throttle bodies (in conjunction with a set of air horns with the stupid holes
epoxied closed) been using the same Uni-syn for 58 years
>:)>:)
 

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Discussion Starter #16
any special tools needed for this? i have a 4 carb vac synch tool if that works. Not really interested in getting a computer out and plugging it into the bike
 

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Well....your vacuum tool will work fine for synchronizing, but you need the diag software to set the TPS. Have you read the workshop manual section on doing this stuff??
 
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