Throttle body balancing

[YourOldNemesis]

Does anyone know:

1. What gubbins I need to do this on a 620ie
2. Where I can get it
3. Where I can get hold of a workshop manual that will tell me how to do it?



Thanks


YON

[MikeBurns]

I don’t think you need to balance fuel injected engines!

[Rockhopper]

Yes you do. It has throttle bodies which meter the air going into the engine. they are just like carbs but instead of mixing the air and petrol they just allow the air in while the injectors spray petrol mist into the airstream. They need balancing just like carbs do.

[YourOldNemesis]

I don’t think you need to balance fuel injected engines!


Shows how much you know! (no offence!)

[MikeBurns]

Hey, I was only trying to help out with an opinion but I wont bother again. :mad:

[MotoNik]

I've not performed the task myself (although I would like to get my SS done), but I believe you will need a set of vacuum gauges (M&P, Demon Tweaks etc) and a Haynes manual will probably tell you, assuming they do one for the FI models. Which I don't think they do...Aaaah....

To be honest, it is not a procedure I've seen any online tutorials for, unfortunately. Could be worth contacting the guy at ducatisuite.com perhaps?

Sorry, I've not been much help, have I?

If you find anything out, let us know - it's something I'd like to know myself.

Nik

[YourOldNemesis]

Hey, I was only trying to help out with an opinion but I wont bother again. :mad:

C'mon - I did put "no offence" after it. Would you have preferred a smiley? - here you go , in fact, have 2.
:D :D

[Bob Dixon]

Hey, I was only trying to help out with an opinion but I wont bother again. :mad:

Mike , please don`t take your bat home because I`m sure that no offence was intended by Charlie.
For what it's worth I think this forum has some of the best technical support you will find on any internet group. Whenever I`ve needed help I post a quick question and within a day I`ve got the info I need. The help on this forum is invariably of the highest quality and I`m always impressed at the technical knowledge and common sense displayed by the members. Unfortunately Mike, you waded in with an ill-informed, potentially misleading comment about something you know nothing about so please don`t get touchy when you are the one who has made an error . You weren`t helping out with an 'opinion' , you were simply clouding the issue, although I`m sure your input was well intentioned. I`m sorry to be blunt but that's the way it is. Many internet forums are rendered worthless by this sort of stuff so let's try to maintain the integrity of this one.
I hear enough nonsense at my local Ducati shop and I come on this list because it's an oasis of common sense!

Fuel injection, in my experience , is even more sensitive to throttle body balancing than carbs. These is because the fuel is metered so precisely the engine will be affected by the slightest imbalance. Carbs often run rich and an overfueled engine will often mask carburation problems. Throttle bodies usually [not always] have vacuum take-offs and can be balanced using conventional vacuum guages.
If you don`t have a set of gauges I have obtained good results by carefully measuring the throttle openings and adjusting accordingly. I always set up the Amals on my Laverda race bike in this way, but they only operate properly at full bore anyway...... A friend of mine who is an expert on high performance engines still favours the old fashioned stethoscope method.....this is where you put a rubber tube into the inlet and listen to the hiss of each throttle when the engine is running, by matching the tone of the hiss 'twixt each throttle body you can obtain perfect balancing. Worth a try if your ears are sensitive enough, he swears by it and has enough race wins to his credit to back up his opinions .
Davida in Birkenhead [the helmet people] sell their own vacuum guages which are pretty good.

:)

[MikeBurns]

yes very blunt - Thanks

[Rockhopper]

I tired the length of hose pipe trick on my ST2 and it does work. I eventually bought a set of gauges though to get it spot on.

A really pukka digital thing that my mate uses can even tell if there is any back pressure in the inlet system , ie if a valve isnt seating correctly.

[Zimbo]

You'll need a pair of vaccum guages, try to borrow a good set, it's cheaper than buying them! I use the Morgan Carbtune ones, recommended.
You'll find a plug on each throttle body, from memory they're 5mm thread slot head screws. Remove them and replace with the appropriate take off fittings (morgan supply a selection in the kit). Connect these fittings to the vaccum guage hoses.
Start the bike (warmed up) and run at just over tickover. The guages should read within 2mm Hg of each other. Blip the throttle a few times and compare readings when they settle.
If it needs adjusting you'll have to study the throttle mechanism to find how to adjust one relative to the other, I've no idea how cos I've never done it.

Alternatively, take it to your local bike shop, they'll do it for you for less than the cost of a set of vaccum guages ...

[nelly]

To balance the throttles on your ie bike you will need a set of gauges.
There are however two "balances" to obtain.
The first is the mechanical balance between the throttles, the second is fine tuning the air bleeds to balance the idle mixture between the two cylinders.
This is where it gets difficult, because you not only need vacuum gauges, but also an exhaust analyser.
The gauges are used for balancing the throttles. You need to close both the air bleeds off completely, connect the gauges to the take offs on the inlet manifolds and the balance the throttles using the linkage.
Once that's done you then need to crack the air bleeds to get the idle mixture equal between the cylinders. This is what the analyser is needed for.
Usually the rear cylinder takes around half a turn more than the front air bleed but that's only a rough guess.
To set the injection up "fully", you need to start from scratch and set the throttle sensor to, but that's another story. :cool: