Balancing Throttle Bodies

Hi all-

Can the throttle bodies on this bike be balanced or not? I am unable to find a reference to the procedure in the manual.

Thanks.

 

There is no official procedure as far as I know, they are factory set and not part of any maintenance, but I'm sure they can be improved upon. Someone very helpfully shared this with me.
The balance is done by the throttle butterflies.
There are no suitable vacuum ports, so use a synchrometer placed in the inlet port to measure air flow.
The actual value is not important as long as they are all equal.

All the plastic above the throttle bodies has to come off.

The master throttle is rear left and is controlled by the eco, the linkages do the other 3.
There are 3 T15 screws (with white paint) to do the adjusting,
one to balance rear-right with rear-left, then one each for the front throttles.

It is a pita job to do but worth doing, and best done when the engine is fully warm.

 

Joined just to answer this. On my 2000 there are all four vacuum hoses stuck to blocking nipples, two on each side of the air box just below the parting line. Connection is as simple as pulling them off the plastic nipple and connecting them to your mercury balancing set. They're even numbered 1 thru 4 on the tube. The balancing is done on the right side of the throttle body. Three are adjustable to match the one reference cylinder.

 

Interesting old thread reboot. Jim you should be aware that you have strayed into the 7th Gen section (VFR1200) which shares nothing in common with your 5th gen. You should also note that the 5th gen is unique in requiring different vacuum settings for the 4 cylinders, unlike the 6th gen that has them all even.

I hadn't thought about balancing a VFR1200 but it does look possible, maybe in two different ways. From images on eBay, there are indeed standard adjusting screws on the throttle shafts that look just like the adjusters for carb balancing. Then there are also some adjusting screws that look to allow fine tuning of air bypassing the butterfly, just like the starter valves do on other VFRs. They don't look like they would be easily accessible on the bike so I assume they are a set and forget at the factory to allow some idle air even when the butterflies are closed.

The image below is apparently off a DCT bike, and shows two ports for vacuum hoses adjacent to each injector; other images show just a single port, so maybe a DCT has some extra finnagling of the FI system? If you could access the vacuum hoses that go to the 5-way connector while the TB is installed, I'm sure you could hook up a set of vacuum gauges as that is just what is done with the 6th gen and the ST1300.

I find it amusing that the throttle cables connect to a very standard looking throttle pulley on the side of the throttle body, and that then drives a potentiometer which talks to the ECU which then operates the stepper motor. I suppose that Honda could have put that throttle pulley anywhere e.g. on the fork assembly and saved a long cable run. But I'm not a bike designer.

 

that video guy invented a nonsencically difficult way to remove front fuel tank bolts, rather than using a socket on a 6" extension, ez and quick.
maybe he just wanted to show off his fancy snapon 10mm wrench.

 

You mean there is ANOTHER tool that I need to buy???

I usually replace those bolts with socket heads and use my T-bar allen key.