Hello, i have a kawasaki klx 250s 2009, i ride this bike the past year, but since the first ride, i feel that the bike have low gear power, like when i go for dirt, and have a big and long climb, i have to go 2nt gear balanced, or 1st not balanced. about the top speed i get 130km/h (80miles). last month i noticed my gear is a 15th front sproket and a 42 rear sproket, 15th front sproket isn't to much for this bike? its the fuel injection model, the engine is like stock.

(sorry for bad english)

 

I thought the stock was supposed to be 14 tooth?

I'm not familiar with the EFI models, but I would think going to a 14tooth or 13 tooth front sprocket would help.

Maybe someone with the EFI version will be able to help you out more. Welcome to the forums as well!!

 

A 14 tooth front sprocket with 42 rear is stock for the 2009 250s. I think this is true even for the EFI models.

A lot of us go down to the 13 tooth for more low-end grunt in the dirt. Heck, I even went as far as putting on a 49 rear (now a 45 rear) and using either 13 or 15 on the front depending on where I'm riding.

You may even get more top speed with lower gearing, but your rpms will be higher.

Welcome to KF. Don't worry about poor English. We're glad to have you here.

 

i'm very glad too, i'm realy thinking in change to a 13th, my doubt is about the rear, if i let stay the 42th ou higher, wich speed do you get with the 13-45? can you do some wheeling? because mine only in 1st , or 2nd with some clutch

 

I suggest you get a 13T front and try it first. That's the inexpensive way to go. A larger rear sprocket will most likely need a longer chain. If 13/42 isn't sufficient, then work on the rear sprocket.

see gearingcommander.com for your speed questions.

 

I'd have to agree with Scott, change the counter sprocket first. I bought a 15t (I mainly do street riding) off ebay for less than $20. The only problem I had was changing it myself, I couldn't get the nut off. So I had it done at the dealership when I took my bike in for the 600 mile service.

Did you buy the bike used? I'm just curious how it got a 15t on there in the first place. BTW, if it has been replaced before you may be able to get the nut off yourself with a breaker-bar. I just think they come extremely tight from the factory.

 

Sprockets really depend on what you use the bike for. I have 13 - 44 sprockets on my EFI model and that is a massive help on the dirt and still pretty good on the road. I would definately not go back to stock. It will still go 70 ish MPH although the revs are a lot higher but once you put some proper dirt knobblies on that top speed is plenty!!!

I would only go to this gear ratio though if you do the clutch switch trick to derestrict the top end revs for the EFI, otherwise your top speed with this sprocket combo will be 55 - 60mph.

Now go forth and do some knarley shizz nizz

 

i think the 13th front sproket is just what i need, on week i ride on the street, but on weekend i go for dirt with friends or alone

 

As mentioned above, removing the front sprocket nut can be a bugger. My technique: flatten the locking washer, put a deep socket or bar in a sprocket hole and lock that against the swingarm (to prevent the sprocket from turning), and use a nice long breaker bar on the sprocket nut. I couldn't get it the first time by standing on the rear brake or with an impact wrench, and I don't like the idea of using an impact wrench on this anyway (others do without worry).