Suzuki GSX650F Forum - www.GSX650F.biz

This is a 'how to' for balancing your throttle bodies so you bike runs nicer and maybe even uses less fuel, but most importantly it runs sweet.

Disclaimer:
Before I start I have to say that I have taken all care to create this how to but I will not take any responsibility if you decide to use this info to do it yourself and cock it up causing the bike to have to visit a shop for repairs.
If you are not confident - DON'T DO IT

Righto.

First thing to do is to check that the TPS is adjusted correctly.
1. Create a lot of slack in the throttle cable. Your user manual will show you how to do this adjustment
2. Remove the RH side cover and find the dealer plug.


3. Remove the protective cap form the dealer plug and put the bike into dealer mode. I use a split pin (you'll notice I have covered the end of it to reduce the chance of shorts) but you can buy a dealer switch from Suzuki at a price around $30 AUD. NOTE: If the pic below dos not make sence for the pin location please say so and I'll explain it better.


4. Turn on the ignition and the dash should show something like this


You'll notice mine shows a _C00. This indicates my TPS needs adjusting. The following is a 'at home' way to do it but to get it spot on you'll either need to take it to a Suzuki dealer and ask them to do it for you or buy SDS
5. Remove the LH fairing and find the TPS


6. Loosen the TPS (DO NOT remove it from the bike). you'll need a TORX fitting T20H I think and it can be rotated to adjust the reading on the dash. It is a finiky, fiddly prick of a job to get right but in the end you need the dash readout to look like this when you have finished and have tightened the TPS (not to tight only by hand. I use a screwdriver type tool).



Now onto the TB balance.
EDIT 11 Apr: I have included a bit more info that I think is important to clarify some things.


NOTE: Leave the bike in dealer mode. If you have started here and not done the TPS check/adjust, put the bike into dealer mode as per step 2-3 above.
1. Remove the tank (you user manual should show you how). to expose the inner workings


2. Locate the IAP sensor


You need to unplug this and remove it with the hoses that are attached to it. This is what you are removing


You can just unplug the IAP sensor and disconnect all the hoses from the engine (those small barbs on the engine will become the test points for the balance tool) but I've said to remove it all so it is easier to see what you are doing, that's all
3. Hook up your balancing tool. I use a Morgan carbtune as I find it the easiest to use and there is no maintenance that goes with it. It is up to you what you use tho.
Locate the adjusting screws for each TB. Here is a pic of cylinder 2


and cylinder 3


Use a torch and take your time, you will find them.
4. Make some kind of thing up to hold your tank above the bike so you can access the adjusters while the bike is running. Here is what mine looks like all ready to go. Nothing pretty, but it works and is safe and secure.


5. Hook up the tank and start the bike. You will a code in the dash that is -C13. This is the code for the IAP you disconnected in step 2 and is perfectly normal. You now need to wait until the bike cooling fan kicks in. This ensures your bike is warmed up enough to do the adjustments. I also use a small fan to blow air onto the radiator and help move exhaust fumes out of my shed. I recommend you do this also as it will get quite hot in there.
This is what mine looked like at first start up


and after it was warm


So you can see I needed to do mine.
6. Adjust each adjusting screw (cylinder) to end up looking similar to this. (Mines not spot on as I still need to run the bike in and I'll be doing it again after the first service. It is better than before tho)


A few tips while adjusting.
*Do not make any changes to the adjustment while the fan is running, wait for it to stop.
*Make small adjustments slowly to be more precise.
*Turning the screw in (tightening it) makes the meter rise (increase in vacuum)
*Turning the screw out (loosening it) makes the meter fall (decrease in vacuum)
*Don't turn the screws out (loosen) too far as they will come out
*At the moment I'm liking 19-20cmHg as a vacuum reading as IMO it runs nice an smooth for a bike
*If you think you have it where you want it, crack the throttle and release it,wait for the engine to stabilize and check the gauge again. This is very important when you are almost finished and happy with the results.
7. Once happy remove the gauges and put your bike back together.

If there is anything you would like clarified please ask and I'll try to explain with a little more detail.

chears

Nice write up Dhula ,seem very easy to do and good pictures.
Its abit out of my league .

Your a legend Dhula , excellent post .

I took my bike in yesterday and had the throttle body adjusted they said it was out of kilt , as i expected the vibations have gone, phew !

The balancing machine y have there is very impressive.

On my next major i've talked a mechanic into teaching me how to do the lot , valves , throttle body , i'll print this and use this a reference.

Part of the ownership of this bike for me is learning how to fix things and do repairs ect.

Nice info dhula, but way beyond my experience. I'll leave that to the experts.

Dealer mode.

Please explain in your step #3 exactly what two pin numbers you are jumping.... They are being jumped/connected together, right?

Thanks...

That's a pretty good info. Thank you and hope to hear more from you.

Thanx!
That does look pretty straight forward!

Looking at the plug (as in the pic) and having the clip at the top, you are looking for the 2 right most pins. The plug only has 4 pins connected and you are looking for the 2 that are above each other.

I think the wire colours are
black/white - top wire
red/white - bottom wire
but don't hold me to it

The important thing is to hold the plug as in the pic with the clip at the top and choose the 2 right most pins to jump.

does that make it clearer ??

Thank you dhula....

This dealer plug is also useful to see other fault codes that can be looked up in the maintanence manual. Did you know the maintanence manual does not show how to get into dealer mode? It must be a secret so we can spend more money having our bikes fixed.

Thanks again dhula.
Excellent article..

How does one learn all of the possible display codes that can be shown when the bike is in dealer mode? Do you have a list that you can share?

So am I reading this correctly, you had to sync the bike up before the first service? When does the manual say this needs to be done?

It was a helpfull response to a post i made about how do y sync the tb as i was experiencing extra vibrations in the pegs and bars, which i ended up getting the mechanic to do it but i will have a crack at it next time as use this as a reference.

Dhula = very clever bloke

Understood, but I asked because his bike needed to be adjusted, and I thought he said this was before the first service. I'm just trying to figure out if I need to check mine.

Hey Packbacker - the manual says to check throttle valve sync every 7,500 miles. You only have to do it with your first service if your bike is one of the E-33 models that has extra emission controls on it.

Dhula - I don't have a cool carb tuner like yours but I do have a vacuum gauge I used to tune a carburetor on a car. Do you see any reason why I can't disconnect the IAP sensor and hoses, put caps on 3 of the cylinders and tune them one at a time?

Because you will go COMPLETELY INSANE before you accomplish anything, adjusting one changes the others