bottom end on my bike is yucky how can i make it better?

i have a 2008 wr250r it has a fmf q4 slip on and 45 tooth rear sprocket (i think the front is 13 i cant be bothred taking the guard off to check)
anyway today i was riding offroad with my cousin for the first time he has a rm125 with a 49 tooth rear sprocket (no idea what his front sprocket was sorry) and his bike has SO MUCH more bottom end power his lower gears just keep on going and going when compared to my bike, and i really liked that about his bike.
will getting a 48 tooth rear sprocket for my wr250r make a noticible diffrence in bottom end power without sacrificing too much top end? (cause i use my bike on the road a lot too)

You're going to have to be bothered to check your front sprocket.
It's 3 bolts.

I have 13/48 and can easily travel at 75 mph on the highway. (I do have a corrected speedo by the way)

I top out at about 84mph.

Bottom line is, gearing is about your only choice for more bottom end unless you want to spend big bucks on big-bore kits and rebuilds.

motokid wrote:

You're going to have to be bothered to check your front sprocket.
It's 3 bolts.

I have 13/48 and can easily travel at 75 mph on the highway. (I do have a corrected speedo by the way)

I top out at about 84mph.

Bottom line is, gearing is about your only choice for more bottom end unless you want to spend big bucks on big-bore kits and rebuilds.

ill check the front sprocket 2moro, i think ill do the same as you, 13/48.(maybe 49) follow up question, will i need a bigger chain?

Stock is 13/43. I dropped one tooth in the front and am happy both on the road and in the woods which is where my WR spends most of its play time.

I have a hard time believing an RM-125 has more bottom-end power - your 250 has twice the displacement.

I'd lower the gearing and install a fuel programmer and practice.

I'm guessing he means to say that it has more get up and go. It's just the nature of the 2 stroke mx bike vs a 4 stroke dual sport. I took my cr250 out last week for the first time in 6 years. Forgot what it was like to pin it right from a stop, night and day difference from the wr250. But then I hit 5th gear and I keep trying to shift thinking "really, that's it???".

I have no idea what you are talking about with bottom end and top end. Are you talking motor or gearing? Our bikes have about 50% more oomph on the bottom end of the rev range, and the 125s climb to a higher peak after we've run out of revs.

They are going to be quicker all around though as they weigh a lot less, have more power, and have gearing optimized for off road with no consideration for highway cruising like our bikes are capable of.

Just about any two stroke is going to feel more snappy off the bottom. Same with dedicated offroad bikes like the WRF models. Hell, even old school 4-strokes like the Honda XRs have more bottom. The WR is a bit of a slug untill you get into the midrange where the bike starts to make some power. A 13/48 setup (the gearing I run) helps, but don't expect a miracle. I find with this gearing a happy cruising speed is around 55-60. Any faster and the little engine feels rushed. This is with a corrected speedo.

The rm125 is a mx bike. Mx bikes tranny's are geared much lower than our WR's are. The WR stands for Wide Ratio. It means we have a Wide Ratio transmission, not a lower, close ratio gearbox like you'll find in an mx bike. It's what makes our bikes better "all-around" bikes. If you want an mx bike, you're going to have to buy an mx bike. The WR250R is not one.

Krabill wrote:

The rm125 is a mx bike. Mx bikes tranny's are geared much lower than our WR's are. The WR stands for Wide Ratio. It means we have a Wide Ratio transmission, not a lower, close ratio gearbox like you'll find in an mx bike. It's what makes our bikes better "all-around" bikes. If you want an mx bike, you're going to have to buy an mx bike. The WR250R is not one.

yeah true.. im just going to change my gearing to 13-49 should be good enough for my tastes =)

Krabill wrote:

The rm125 is a mx bike. Mx bikes tranny's are geared much lower than our WR's are. The WR stands for Wide Ratio. It means we have a Wide Ratio transmission, not a lower, close ratio gearbox like you'll find in an mx bike. It's what makes our bikes better "all-around" bikes. If you want an mx bike, you're going to have to buy an mx bike. The WR250R is not one.

If WR stands for wide ratio, what does YZ stand for? Yakuza?

No, not that.
Yamaha has always put the letters YZ somewhere in the model designstion of their motorcycles that were built with competition in mind.
Since the YZF-R1 came out, that has been blurred a bit since the YZF-R1 is sold as a street bike to anybody with the money to buy one.
That's the idea, though.
What the Z in YZ means is anybody's guess.

Gearing and rev the piss out of it, I personally am very impressed with how this bike runs "coming from a DR650 too".

Pokey wrote:

Gearing and rev the piss out of it, I personally am very impressed with how this bike runs "coming from a DR650 too".

would revving it that hard all the time hurt the bike? (this is my first bike and im like inlove with it, dont want to hurt it lol)

YZEtc wrote:

What the Z in YZ means is anybody's guess.

IMO all the letters mean nothing, they're just designations.

The WR doesn't shine at the bottom end but it does like to rev. The bike has a rev limiter so you shouldn't have to worry about engine damage. If you want more bottom end, gearing is really your best option. Last year, I swapped the front sprocket to a 12T. Still had the original 43T in the rear. Nice improvement!!! This year, I had to do a full drive replacement, so I went with a 12/47 combo with a new chain. Yeee Haww. Way better in the trails. Now I can get out of 1st or 2nd in the trails. Better bottom end for sure. The top speed is still fine but the rpms are not as low at hiway speeds. That's the trade off. I went on a long road ride with a buddy so I just swapped the front sprocket back to a 13T for the day. For now, I would drop to a 12T in the front. Get used to the bike. See how you like it. When it's time for a new chain, you'll have a better idea of what you like. 12/48 for great low end grunt, 13/43 for low hiway rpms or something in the middle.
Cheers

rahiminia wrote:

Pokey wrote:

Gearing and rev the piss out of it, I personally am very impressed with how this bike runs "coming from a DR650 too".

would revving it that hard all the time hurt the bike? (this is my first bike and im like inlove with it, dont want to hurt it lol)

I ride mine like it is a 125cc two stroke. Wide open and slipping the clutch more often than not. 20k trouble free miles so far running it this way.

Head porting.

The first thing that I noticed after getting my bike back together with a fully ported head was that the bottom end is much better. I actually have some grunt down low now.