hi im new to gstwins and new to the gs im power mad so im wanting any tips for tuning the gs 500 engine
1st off ill give you what iv got so far

the bike will be dressed in gsxr 750 k4 outfit with gsx 1100 forks twin 6 pots extended swing arm and painted in white and grey

the engine :-

lightened and ballanced crank
removed ballancer shaft
either gsx 1100 or hayabusa cosworth 85mm pistons
modified cam chain wheels to make timing ajustable
modified ignition to advance timing

im after any info on doin the gsx head swap , wich 1 is best and so on ...

also i think the gr650 cylinders has different linders maybe thicker so i can fit the 85mm pistons without changing the gs liners to gsx but i dont know if its taller without spending money buying 1

does anyone know if i can upgrade the cdi unit at all ?

and last , i was thinking about a turbo if the gr block is taller this will lower compression i know the gr engine has a 60mm stroke and the gs has a 53mm (approx) so should be around 3.5mm if i deck it by 1.5 to 2mm this should lower compression enough to turbo but is the crank any good or will it spill its oily bits the 1st time it comes on boost

any help would be great
steve .

I have got a good tip, jack your license plate up, remove the GS500 and fit a GSXR 750 to it. You will save yourself lots of time, money, effort and heartache 

iv started it nw tho

If your looking for more power, many have said, many times... buy a bigger bike. I have heard that the SV 650 isn't much of an improvement. I suggest a four.

Without knowing for sure it can all be done?.....oh dear.......still never mind.......let us know how you get on, esp` with the pistons and turbo  

Welcome to GSTwins morepower - but based on cost VS benefit, if you really are power mad I would not recommend a GS500 as a starting point.

With the piston, head and cam modifications you have listed, there will be a substantial cost on parts, machining and labor... even more so if you decide to turbo it. If you did carry out this work, remember that the gearbox and drivetrain is rated for a 45hp engine and will be more prone to wear/breakage. If its not built and tuned right ($$$) you would be forever chasing reliability problems. Even if you did make a 50% power gain with N.A engine mods (which is unlikely), a highly stressed 70hp still wouldn't compete with a stock 04 GSXR600 that easily makes over 100hp

I have fairly standard mods like K&N, slip on +jets and the 500 really comes alive - being a learner and fairly new to bikes it was impressive when I first started riding but having seen how much faster a GSXR600 or R6 is, I understand my little 500 will never be a powerhouse. Sorry if it seems like I'm   your ideas down - just enjoy the 500 for what it is!

What have you actually bought so far? Why are you tackling so much at one time? Is this your first project bike, or have you been reworking bikes for a while? Why a GS? What are your goals?

it was cheep and i just wanted to see what i could make out of it ...iv made some pretty rediculous machines right now im making a tsr125 look like an 2000 rm 250 with a tm400 engine
i think this will be a decent screamer when its finished
iv done about 40 bikes and never left any engine standard i just enjoy it  . it doesnt have to be faster than bigger bikes just as fast as it can be + the guys on bigger bikes are usualy 2 scared to open throttle on or even near corners so ill be way ahead
roads are pretty bendy in england light weight gs is good for throwing around corners

im sortning the brakes and suspension 1st so not bought engine parts yet altho i will buy the gsx head this week or next and mod it myself fit it to a standard engine with standard valves just to see how well it works before i start messing with its flow

ow and if i had a bigger bike with a bigger engine this wouldnt stop me tuning it to its full potential 

Okay, cool. Sounds like a fun project.

Unfortunately, the GSXR head swap was a one-off project, and the guy who did it isn't a member here. You might find this article about his bike helpful though:

http://www.sportrider.com/bikes/146_0110_suzuki_gs500/index.html

As for the cylinder liners... Aren't those a pretty common part? I'm sure you could order one from somewhere. The GR650 isn't a terribly common bike. You might have better luck finding the liners from one of the bigger GS 4 bangers - those were very popular dragbikes, and I'm guessing that oversided liners are readily available if the stock parts aren't already suitable.

Regarding suspension: R6 shock (specific models) is the blingiest direct swap, but is almost certainly undersprung for your use, esp with a lengthend swingarm. A Katana 750 shock is a good bet, as may be some of the older GSX-R shocks. Full front end swap is almost certainly your best bet.

And yes... The stock GS500 crank really isn't suitable for the kind of power you're thinking of putting through the engine.

i went for a gsxr600 k1 rear shock and gsx 750 front or 1100 with anti dive but keeping standard wheels
i dont think ill find a billet crank anywere thats not way ott on price so probably a no go on the turbo unless i keep boost low or stock up on cranks 

There is a much cheaper way to achieve the same result:

If you are looking for a programmable aftermarket CDI I recommend Ignitech or Zeeltronic.  Both are excellent units, but the English customer service from Zeel is better.

I don't know how hard it is to swap a oil-cooled GSX/GSXR head, done by Cedric Smith.  I'm sure it involves a lot of fabrication work.  I do have some experience with oil-cooled GSXRs.  I can tell you to avoid the early GSXR 86-87 heads as they are prone to cracking around the vavle seats.  The 88-89 GSXR-750 "dot" head is one of the preferred oil-cooled heads and was also used on some Katanas.  Also avoid the 91-92 GSXR750 "shim" heads as it is harder to find cams and some believe the lash adjustment mechanism isn't suitable for high-performance.  The 1127 heads are similar to the dot head but have a different intake port angle and it is harder to find correct intake boots.  If you're up to the machining and welding, it would be cool to see.

Quote from: more power on March 30, 2011, 01:42:08 PM

does anyone know if i can upgrade the cdi unit at all ?

Its not CDI. its transistorized. common mistake people make is calling the igniter unit a cdi box.  But since its not cdi stock, an msd ignition would be worth looking into.  I was thinking about a way to incorporate one onto my bike but dont have the money to experiment.

QuoteI don't know how hard it is to swap a oil-cooled GSX/GSXR head, done by Cedric Smith.  I'm sure it involves a lot of fabrication work.  I do have some experience with oil-cooled GSXRs.  I can tell you to avoid the early GSXR 86-87 heads as they are prone to cracking around the vavle seats.  The 88-89 GSXR-750 "dot" head is one of the preferred oil-cooled heads and was also used on some Katanas.  Also avoid the 91-92 GSXR750 "shim" heads as it is harder to find cams and some believe the lash adjustment mechanism isn't suitable for high-performance.  The 1127 heads are similar to the dot head but have a different intake port angle and it is harder to find correct intake boots.  If you're up to the machining and welding, it would be cool to see.

exactly what i needed to know cheers 
depending on how much of a ball ache it is to do i may make a few extra and offer them on here as a kit if theres any interest

electronics will be last on the list but it will be getting upgraded somehow so ill post my findings , im looking at a loom swap tbh for something from a fuel injected bike , electricity is not my strong point ... at all . will be pullin in a m8 or 2 to help all depends on turbo or non turbo im still in 2 minds

Looking at my fuel injected 08 Ninja 650R (parallel twin) and my GS500 side by side, the fuel injection system shouldn't be too hard to swap as long as you have a donor bike to pull parts from or at least make a full list from, before you scavenge ebay.

Quote from: tb0lt on March 31, 2011, 09:03:58 AM
Looking at my fuel injected 08 Ninja 650R (parallel twin) and my GS500 side by side, the fuel injection system shouldn't be too hard to swap as long as you have a donor bike to pull parts from or at least make a full list from, before you scavenge ebay.

ill buy a haynes manual and ask my auto electrician freind if he thinks it can be done but it sounds like the perfect swap to me. thats just saved me a couple hours reserchin 

Quote from: utgunslinger13 on March 31, 2011, 02:31:57 PM

only have pictures of the strip down so far. iv only had the bike a week im waiting on parts bein delivered i can add the pics of the strip if people wanna c it