Improving throttle response of a GSX1200

[rogson]

I want to improve the low to mid range throttle response of my GSX1200. It monentarily feels flat when I wick-on the throttle in the low to mid range. My previous bike was a 98 ZX9R (kermit) which had great low to mid range throttle snap (much like a 2 stroke and heaps better than the R1 and 900RR at the time), but I sold it because I thought I needed to slow down and ride "maturely". I bought the GSX because it has good mid range power for road riding, is comfortable, can accomodate a pillon, feels small and agile (for its size), and I could see there was potential to ride it aggressively.

I am currently upgrading the suspension (heavier springs and RaceTech emulators in front, Ohlins in back). This will allow me to attack the corners like I used to on kermit but I would like to improve the throttle response. I have looked at improving the breathing with a K&N filter, a dynojet kit and an aftermarket exhaust, but I'm not really interested in these if all they do is increase top end performance - that's not what I am after.

Any thoughts?

[F5 Dave]

Totally unfamiliar with the bike, but a jetkit is required when you change to a K&N (or power commander for an injected bike). Jet kits if set up properly will help throttle response but might not add much power. Dynojet kits are sometimes known to wear the needle-jets quickly, not sure if they have fixed this problem.

I’d try (& did -actually on dyno last night with one in my RF) a Factory brand jetkit, if they do one for your bike. Std bikes are compromised by emmision testing. factory

An ignition advancer may help as well.

[riffer]

I’d try (& did -actually on dyno last night with one in my RF) a Factory brand jetkit, if they do one for your bike. Std bikes are compromised by emmision testing. factory

What were the results Dave?

[F5 Dave]

Well replacing the worn emulsion tubes helped get rid of a lot of the black smoke it was belching on the overrun (never noticed it on the road). Hopefully this alone will help fuel economy.

Power was up ~2hp from about 6000, hardly worth it in itself, but throttle response seems better, real smooth. Really I have only chosen the correct mainjets so more tuning may result in further improvements, but to be honest the bike runs quite nicely already & I haven’t even sync’d the carbs yet.

Peak power wise not totally sure. It was reading ~108 I think which is about 10 down on what the mags used to quote & ok the bike does have 54k on it, but there was another RF in the database with 6k on it & a yoshi slip on & the curve matched it so it might be the dyno reads low. I care not, the bike hardly sees redline (unlike my 750) & the torque curve is flat as.

[vifferman]

I want to improve the low to mid range throttle response of my GSX1200. Any thoughts?

Ask Lou - he's had his bike fettled and was really pleased with the results.

[rogson]

I have been considering ordering a G-Pack Timing Retard Eliminator (TRE) from a French outfit (Nikko Racing) for my GSX1200 but have come across a German website with some interesting relevant info (there is very little info. in english because the GSX1200 was never sold in the US or UK). The article is attached to this post. It actually discusses a GSX750 but I have checked the fittings and wiring on my bike and it looks to be exactly the same.

My interpretation of the translation by google (pigeon english at best) is that the authour has deduced that the timing retard (in second and third gears) is activated by contacts on the gear position sensor and can be deactivated by simply disconnecting it at the connector plug under the tank! If this works its a lot cheaper than the $300 or so I was going to fork out for the G-Pack (also, if it works - what's in the G-Pack!).

I've seen discussion on TREs (some on KBer) where the resistance of a circuit is changed to "fool" the ignition system the bike is in a high gear (i.e. where no retarding is done). Perhaps fuel injected bikes need this whereas carburetted ones don't?

Pulling the connector is such an easy thing to do but I get the impression (again from the translation) that the author was worried about damaging the CDI unit - and that sounds very expensive!

Can anyone help me with the interpretation of the document (and perhaps navigating around the site a bit to see if there is more info.)? Please send me a PM if you can.

Btw - I would imagine Bandits and GS1200SS have the same timing retard system.

[Pwalo]

Mr Rogson,

As I understand it the GSX1200 uses the same motor as the B12. Might be worth checking out the Bandit owners web sites to see what they have to say.

No doubt if it's a US spec bike you'll have to look at the idle mixture, and pilot jets.

Good luck, and nice bike. Can't believe how compact the GSX1200 and 750 are.

[WINJA]

I have been considering ordering a G-Pack Timing Retard Eliminator (TRE) from a French outfit (Nikko Racing) for my GSX1200 but have come across a German website with some interesting relevant info (there is very little info. in english because the GSX1200 was never sold in the US or UK). The article is attached to this post. It actually discusses a GSX750 but I have checked the fittings and wiring on my bike and it looks to be exactly the same.

My interpretation of the translation by google (pigeon english at best) is that the authour has deduced that the timing retard (in second and third gears) is activated by contacts on the gear position sensor and can be deactivated by simply disconnecting it at the connector plug under the tank! If this works its a lot cheaper than the $300 or so I was going to fork out for the G-Pack (also, if it works - what's in the G-Pack!).

I've seen discussion on TREs (some on KBer) where the resistance of a circuit is changed to "fool" the ignition system the bike is in a high gear (i.e. where no retarding is done). Perhaps fuel injected bikes need this whereas carburetted ones don't?

Pulling the connector is such an easy thing to do but I get the impression (again from the translation) that the author was worried about damaging the CDI unit - and that sounds very expensive!

Can anyone help me with the interpretation of the document (and perhaps navigating around the site a bit to see if there is more info.)? Please send me a PM if you can.

Btw - I would imagine Bandits and GS1200SS have the same timing retard system.

I MADE MY OWN TRE , THE GPS WIRE IS IN A BUNCH OF 3 , YOU NEED AN OHM METER , UNPLUG THE GPS FIND THE RESISTANCE FOR FITH GEAR BY PUTTING IT IN FITH GEAR , GO TO DICKSMITH AND GET ABOUT A 1/4 OR 1/2 WATT RESISTOR OF THE SAME VALUE , LEAVE THE BLU WIRE IN ITS FOR THE NEUTRAL LIGHT, DO NOT CUT ANY WIRES , THE PINS CAN BE FLICKED WITH THE RIGHT TECHNIQUE, IVE DONE THIS TO 3 GSXR1000S ALREADY

[WINJA]

HERES A FINISHED ONE , FUCKED IF I WAS GOING TO SPEND $300 FOR A NIKKO OR IVANS TRE

[zeRax]

GOOD NOW MAYBE YOU CAN MAKE YOURSELF A BETTER CAMERA SO YOU WILL NEVER POST PICTURES OF GIANT BLOBS AGAIN

HAHhah

[WINJA]

GOOD NOW MAYBE YOU CAN MAKE YOURSELF A BETTER CAMERA SO YOU WILL NEVER POST PICTURES OF GIANT BLOBS AGAIN

HAHhah

THANKS FOR YOUR INPUT

[Pixie]

I performed the carb tweeks as outlined on www.banditsrus.com/fastlarry/banditfaq.htm
and the bike is very smooth at low revs and idles without choke when cold.

[rogson]

Pixie

Thanks for the web page reference. I found what I was looking for under the heading "Ignition Retardation Wire". My bike has the wires they describe (even though its not a Bandit). I suspect yours has them too.

[Pixie]

Pixie

Thanks for the web page reference. I found what I was looking for under the heading "Ignition Retardation Wire". My bike has the wires they describe (even though its not a Bandit). I suspect yours has them too.

Thanks for that,I was looking for the reference yesterday but couldn't find it.Let me know what effect it has on the bike.
I have a Kerker can going cheap if you are looking for a can.(but the GSX has twin pipes doesn't it?)

[Pixie]

I had a look at the translation of that german doc.
I think what he's saying is that although he was worried that disconnecting the wires for the 2nd and 3rd gear position sensors might damage the igniter unit,he concluded that it won't.
So I checked the gear position switch with a DMM and came to the same conclusion.
The position switch merely connects the relevant gear position (2nd or 3rd) or neutral to ground (the black/white stripe wire).
In 1st,4th and fifth gears these wires are open circuit,so disconnecting them will have no detrimental effect.
So disconnecting the 2nd and 3rd gear position wires (red/black stripe and green/blue stripe) will let the igniter operate as if it was in 1st, 4th or 5th gears or neutral.
I don't know what the Commercial TRE does,but I suspect it does not connect to the gear position sensor switch connector.If it does then I suspect it only leaves the 2nd and 3rd gear wires disconnected and produces income for the manufacturer.