Suzuki GSX650F Forum - www.GSX650F.biz

For those that have not had to take the gas tank off yet...this is what it looks like underneath it. The quick release connection on the fuel hose was a pleasant surprise also

Well it appears the cram packed it all in there as neat as humanly possible

Does anyone know where the vacuum inlet caps and throttle valve synchronising screws are in the photo??

I dont have the service manual at the moment.

I may be wrong? There are only 2 TB's with 2 bores in each body. I saw only 1 balance screw, between the #2 & #3 cylinders...I only assume you balance the the 2 bodies to each other with the one screw??? I did not look for vacuum ports. I was under the tank to change the rough cable adjust on the throttle cable, I just gave the TB's a quick glance, without moving any hoses I remember 2 TB's and one balance screw...I have been wrong before

GSXFun - I've only got the service manual for the carburated bandit 2001 model. On there it shows 4 screws & 4 vacuum ports for balancing. But i'm not sure how it will be on the '08 FI model. Am guessing its still the same and i suspect its located where both the quick release fuel hose connectors are lying on your photo above but i could be wrong.

The balance screw you refer to between cylinders #2 and #3 - could it be the idle adjuster??

The only way to confirm all this is to have someone who's got the manual to check it out for us.

Made a quick call to my local suzooks dealer and i'm told the throttle bodies for the bike is below the airbox and thus needs removing to get to it.

if someone has the service manual, can they confirm this please??

This would only be true if you stood the bike on it's nose, my above photo confirms this, some models are like that, but not the GSX.

You may be right, GSXFun.

I guess i really need the Service Manual now to know for sure. Have asked 2 UK dealers about the manual and was quoted price of £75 with a likely waiting time of 5 weeks for delivery! Yikes!

If thats the case then i will order it from the US from RepairManuals for $111 USD. At least they say they have it in stock at about same price!

Okay, i downloaded the service manual for the bandit 1250 K6 to check the throttle valve sync procedure which would be similar i'm assuming.

It seems you need an SDS tool to do the sync'ing. And only suzooks dealers have them.

So that's that. Unless u can put bike into dealer mode then only way is to let dealer do it. bummer!

And no, u dont need to remove air box for the sync'ing.

Sorry i meant to say K7 Bandit.

Further update:

It seems you use the air screws (on TB) for the syncronising (on K7 models onwards i guess).

And, i think but not 100% sure - if u have a Mode Selector Switch, it would be possible to do the TB Sync without needing the SDS.

It appears the SDS (suzuki diagnostic system) is there only to monitor values prior to sync'ing but again could be wrong.

Here's what i am abit annoyed at -

A deep dependence on the dealer or some high-tech gadget to do something that did not require it before.

I dunno - but the term, "they got me by the b*lls!" comes to mind easily.

Okay, what i'm about to explain is purely for academic purposes ONLY, and for the benefit of those, like myself, who want to learn/understand a little more about throttle valve synchronisation (tvs) inspection & adjustment at the usual service intervals. I want to freely share what i know so far, but if this doesn't interest or bores you then feel free to skip to a more interesting topic elsewhere.

Also, I do not guarantee the accuracy or depth of detail of the research i have uncovered and - IN NO WAY AM I SUGGESTING THAT OWNERS SHOULD DO THIS PROCEDURE THEMSELVES DUE TO WARRANTY ISSUES, POSSIBLE DESTRUCTION OF THEIR OWN BIKE, ETC.

Now thats out of way - i have discovered that, aside from our own bikes, other owners of SV's, VStroms, Gixxers and Bandits with K7 models and higher, appear to require the same procedure to do the tvs. Makes sense as its unlikely suzuki would want to make life difficult for their dealer mechanics.

For the procedure the mechanic will need a manometer (vacuum gauges) and either the SDS (Suzuki Diagnostic System) tool or the Suzuki Mode Select Switch tool, with possible exceptions that some models may not have the 'Mode Select Switch' option available to them (?Vstrom 650?).

Oneida Suzuki sells this mode select tool - part no. 09930-82720:

http://www.oneidasuzuki.com/store/parts ... ector.html

The more common manometer can be picked up from various online sites.

The SDS is not available to mere mortals!

Briefly, disconnect the four (for I4 engines) vacuum hoses on TB and the IAP sensor coupler. Then connect up the gauge hoses to the four vacuum nipples of the TB and switch on the SDS or Mode Select Switch. Warm up engine and check idle rpm before playing around with the air screws to equalise the vacuum (#1 to #4) of each cylinder. Once done put everything back the way it was. And thats essentially what tvs procedure is all about - told you its not detailed!.

Next part of my post i will explain what other owners have done in order to try and do it themselves... but he DISCLAIMER above still stands!

ok, I forgot to mention that for the tvs work you need to keep the fuel line attached to the tank or get some kind of extension hose but i think its possible to move tank in such a way as to enable work to be carried out while fuel hose is still attached.

As i said, some owners of K7+ suzuki bikes have resorted to using a workaround to avoid having to use the Mode Select Switch tool. Its a crazy idea but appears to work. However, i am advising that NO ONE HERE SHOULD ATTEMPT THIS unless they're sufficiently mad! I describe it here only for entertainment value... so be warned.

somewhere on the bike there is a connector with a rubber cap on it. You'd need to refer to the SM for its location but this is where the mechanic connects up his Mode Select tool. Six wires run from the connector and when you stick in the Mode Select tool, it shorts wires #1 and #2 which are the red-white and black-white wires. By switching the Mode Select Switch to ON it will then put the bike into Dealer Mode.

When you turn ignition on (but not start bike!) there will be a -C00 on the display. Its at this stage that you can play around with the TPS setting if i'm not mistaken which may or may not cure the throttle jerkiness reported in other postings.

Now start the engine to let it warm up to specified criteria which i wont go into here, and apparently (i cant confirm this yet) the ISC (idle speed control) valve is then automatically set to syncronisation mode ready for the TB to be balanced with the gauges. So it appears (could be wrong here) as if there isn't a mechanical idle screw on the bike since its all done electronically nowadays.

The workaround is to manually short the wires #1 and #2 by using, of all things, a paperclip! Or better still, use an insulated wire.

So there you have it. And if our bikes do not have the option for plugging in the Mode Select Switch then this DIY method will be impossible, and you'd definitely need to pay a visit to your local dealer. I would strongly advise to let the dealer do the tvs anyway.

There are probably gaps in my explanation so don't flame me to say so since this is a slow learnin process for me. I hope to have the GSXF SM soon and will be able to verify/update things.

Until then, i'm as much in the dark as you are!