Hey guys, Surge here, ive had my 09 GS500F for about a year now and to be honest i love the bike but i wish it had a bit more power at the start lol

ive never been be on performance mods much and doing some research iam unsure of the mods i can do to get the bit of power it needs.
I want to try to keep the mods to a minimum to not take away from the bike but to add

Couple people say to change to smaller front sprocket to like one tooth less but i also read that chain-wear is effected and gas millage also drops,
others say install bigger rear sprocket like to 44-46T should give that power i need but high RPS are effected like on freeway

Also ive read regarding the ignition advancer which i also read that oil usage increases

So i am just looking for answer from people who actually tried these mods and have some actual results and experience they an share!
Thanks much!

Ignition is computer controlled on the "F" models - therefore no ignition advancer available.

Sprockets is simple math of number of teeth on the front versus the number of teeth on the back. Smaller front or bigger back has the same effect.
A properly tuned GS with good plugs has good power and mileage.

One difference is to change the pilot jets up one size. In Europe they were larger but reduced by one size in the US for emissions. Changing the pilot will give more low end power.

Oh, nothing you do will effect oil usage. Oil usage pretty much depends on wear in the engine: oil leaking through valve stem seals and around the pistons and so forth.

Thanks for the fast reply!   
I will go look in to the re-jet options 

and thank for clearing up regarding oil usage 

A $15-20 dollar sprocket and an hour or less of your time is all it takes to try a different front sprocket.  Many here have used a smaller front sprocket for a bit more pull.  Some put them on to enhance wheelies.  A few have used a larger front to reduce freeway revs and get a bit more mpg.

I ran a 15T front on my 97 for about 40k miles to make it easier for the bike and my 240# carcass to get going on steep uphill starts in the mountains.  Never noticed any difference in mpg or chain life.  I like the standard gearing on my current 02 but more recently I've put a 15T on to keep it closer to standard revs with larger rear tires. 

http://www.gs500.net/gallery/data/500/GSbrakechainlog.jpg

Thanks for responding, i think i will after all do the front sprocket change to 15T - sounds like its the minimal change that wont effect my bike as much in the efficiency and will give a bit more performance at low end.

I looked in to the carb rejeting and its just too much work and time so i will invest in good quality front sprocket and go from there

Thanks again!
PS: My WIP GS500F

[attachment deleted by admin]

Redline, I do a lot of flat track racing. I'm sure that anyone who races will also be inclined to tell you that gear ratio's are a little complicated  depending on when you want the power that you are looking for. 1st , you would have to know the final gear ratio that you actually have. There is a formula to determine what ratio you actually have but it is unless you have a real understanding of this. You would have to to know the final drive ratio of the transmission, the ratio of front and rear sprocket and finally the height of the rear tire. To the the beginner it is much easier to change the front or rear sprocket. Just remember that every time you change the front sprocket it directly effects the rear one by around 3 teeth. With this being said, suttle changes are more easily made by increasing or decreasing the rear sprocket number of teeth. One of my race bike is a 250cc viper racing engine. When I race it I only put enough fuel in it to complete a race for various reasons. It gets about 71/2 miles to a gallon, if I were to change the front sprocket by a tooth it most certainly effect the mileage by almost 1.3 miles to a gallon. Which means I may not finish a race do to running out of gas.
       I also have to agree with Adidas that a properly tuned machine should give you ample performance that you desire. He is also on the right track that oil consumption can only be effected by the condition of the engine UNLESS...  you are maintaining a constant high rpm. as we do in racing flat track. Higher rpms. for a long period of time can cause the inner workings of an engine to run hotter than normal use on a street bike's engine. So you should not ever see a difference in consumption.
     Chain wear will only show if the front sprocket is so small that the chain is force to bend to a smaller circumference. This you will not see on a street bike set up.
      Now knowing all of this, yes it's easier to play with the front sprocket as opposed to the rear. And yes again it is 1/2 the price of a rear sprocket change.  BUT... minor changes in jetting ( jets only) is just as cheap as the cost of the front sprocket price. I know this may be over explained but try to stay CLOSE  factory setttings and make minor changes to jetting only. You'll be better off unless you are looking for a drastic change in performance.. GO FAST AND TURN WHERE THE ROAD TAKES YOU....

Thanks Donnie for your input on this - you state good points!

I need to make a decision before riding season starts but before that i'll have to compare the new information from you guys and see what my best option will be...

Sprocket change sounds easy but rejet also makes sense since i want to keep it as original as possible...

I shall wait with any mods until im sure that the option i select will be the one i can do and the outcome will be effective
Thanks

If you want to start calculating before just throwing a sprocket on and trying it here is basic GS500 gearing info and tire dimensions:

Good information Jack, That will give every one something to chew on! 

Thanks gsJack, this will definitely give me more to go off on  

Sorry for being a total newbie to this   
i just now need info how to interpret the data and figure out the formula to use to calculate my bike

Thanks for all the help and info!

Hey just thought i update on my status...

As i was deciding what mod to do... the decision has been mad for me... kind-of sort-of 

After no ridding for couple of months due to injury  ive decided to get it started and take it for a spin, well since i was low on gas and live near by i thought ill just ride over on reserve and gas up, i got the bike started and on my way there it stalled so i got it to run somehow again and made it to the gas station, after that i when for a short ride and parked for the night. A day later i am trying to get it to start and no go
Long story short: i flooded the carb's, which flooded air box and the spark plugs. 
Took it apart last night. Cleaned the spark plugs, drained the gas from air box and cleaned air filter also drained the carb's. 

Now just wondering if i should rebuild the carbs with new jets as suggested above since i am half way there lol cause i was just thinking to clean what i see and put it back together and try to fire it up.
I didnt smell gas in the oil but ill prob change that just in case eh

I hear there is carb rebuild kits... which one is good and which one is a waste?

I personally rejetted my carbs and bought the jets at my local dealer.  The only change from stock was a K&N drop-in filter without the restrictor ring and I settled on 20/60/142.5 for the jetting; I must say that gave it way more oomph than stock and it now pulls hard across the rev range and gives much better launches.  With some practice it's possible to pull the carbs, change jets, and have it back together within 45min or so.  I'm currently putting on a different exhaust so we'll see how the jetting holds up.

Quote from: radodrill on January 29, 2014, 11:27:15 AM
I personally rejetted my carbs and bought the jets at my local dealer.  The only change from stock was a K&N drop-in filter without the restrictor ring and I settled on 20/60/142.5 for the jetting; I must say that gave it way more oomph than stock and it now pulls hard across the rev range and gives much better launches.  With some practice it's possible to pull the carbs, change jets, and have it back together within 45min or so.  I'm currently putting on a different exhaust so we'll see how the jetting holds up.

Hey how did you exhaust upgrade effect your new jetting?  Did you have to modify the air mixture screw?
I have just re-jetted my bike and i also have K&N drop-in and OEM exhaust modified with out restrictions (straight pipe style). Looking for correct air mixture screw adjustment level.