why does my yz only have 5 gears

D

dirtbikerida63

Member

Apr 7, 2008

61

0

• Jun 22, 2009

• #1

i have a 2003 yz125 and it only has 5 gears. i also have yz80 with 6 gears. it seems like almost all motocross bikes have 6 speed trannys except mine. Is this the way yamaha made the bike or was it something someone did to it?

 

J

julien_d

Member

Oct 28, 2008

1,788

1

• Jun 22, 2009

• #2

Most mx bikes have 5 gears. Every YZ125/250 I've ever ridden was a 5 sp.

 

K

kawraper

Member

Mar 4, 2009

100

0

• Jun 22, 2009

• #3

I know kaw uses 6 speeds

 

D

Deadohiosky39

Member

Jul 12, 2008

146

0

• Jun 22, 2009

• #4

Every bike i've ever had has been 5 except a kx60 when i was younger which had 6. I was thinking some bikes even had 4 gears. Like the yz400/426 or some of the big 4 stroke ktms maybe. I'm not positive.

 

XRpredator

AssClown SuperPowers

Damn Yankees

Aug 2, 2000

13,504

19

• Jun 22, 2009

• #5

the YZ125 went back and forth between 5 and 6 speeds in the last few years. I'm not sure when it had which, but there's nothing wrong with your bike.

 

M

motodr9

Member

Sep 1, 2003

184

0

• Jun 22, 2009

• #6

Oem

In 2003 Yamaha put a 5 speed trans in the YZ125. I guess they thought weight savings and lower production costs were the way to go since everyone was buying four$trokes.

 

IndyMX

Crash Test Dummy

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Jul 18, 2006

5,548

2

Amo, IN

• Jun 22, 2009

• #7

Most people don't use anything more than 1 thru 3 anyway.. so what's the point of having 6 ?

On my 450, I know for a fact that I have never had it in 5th gear on a track.. Might as well take that gear out.

 

whenfoxforks-ruled

Old MX Racer

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Oct 19, 2006

8,129

2

Merrillville,Indiana

• Jun 22, 2009

• #8

The 2 stroke haters stole 6th gear to keep it slow enough for the 250fs? Joking! 3rd gear will put most people in the hospital. As said, Yamaha made it that way, it said so in the brochure.

 

2-Strokes 4-ever

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Feb 9, 2005

1,842

4

Missouri

• Jun 22, 2009

• #9

Yamaha makes a really good 125 motor. They thought it so good (fast and powerful) that they could get away with a 5 speed, even though all other 125's have six.

The Yamaha still needs a six speed IMO, but I don't know if that short coming is enough to NOT buy it. It's still a good bike.

 

XRpredator

AssClown SuperPowers

Damn Yankees

Aug 2, 2000

13,504

19

• Jun 22, 2009

• #10

Honda had a five speed 125 for a couple years too, so don't think Yamaha invented the concept.

 

O

OriginalRider

Member

Nov 23, 2008

124

0

• Jun 22, 2009

• #11

2003 YZ125 is a 5 speed.Those bikes make great HP to about 37+ with about 25+ FT LBS that's very good for a 125.

 

2-Strokes 4-ever

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Feb 9, 2005

1,842

4

Missouri

• Jun 23, 2009

• #12

XRpredator said:

Honda had a five speed 125 for a couple years too, so don't think Yamaha invented the concept.

Click to expand...

Oops, I stand corrected.
Dumb idea by Yamaha AND Honda then.

 

whenfoxforks-ruled

Old MX Racer

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Oct 19, 2006

8,129

2

Merrillville,Indiana

• Jun 23, 2009

• #13

2-Strokes 4-ever said:

Oops, I stand corrected.
Dumb idea by Yamaha AND Honda then.

Click to expand...

Its not like it lugs the motor, it will pull the 5 speed fine. And its less work for the rider. And its the best engine for modding to a 144.

 

C

cowasucky

Member

Feb 23, 2009

170

0

• Jun 24, 2009

• #14

I bought an 03 yz85 which does have 6 gears, but I could only get 5. I switched to a heavier transmission oil (Belle Ray 85w) instead of the 10w 40 the prior owner had in it and viola........ 6th gear !!!!!!!!!

 

M

mas2de

Member

May 3, 2009

45

0

• Jul 4, 2009

• #15

Alot of mx 2 strokes that I've heard of played around with gears.
Deadohiosky39 you are correct. The larger mx 2ts tended to have 4 speeds while alot of the small bikes had 6. I believe it was all for close gear ratios. Not for any o/d.
I know a somewhat common mod for the old Yamaha YZs was to put and IT (enduro 2 stroke) bottom end in it so they could have the 5 speed instead of 4. As far as I know all the enduro bikes had an extra gear. I'm not sure on the ratios though, or how exactly they compared to the mx.

 

A

adam728

Member

Aug 16, 2004

1,011

0

• Jul 4, 2009

• #16

OriginalRider said:

2003 YZ125 is a 5 speed.Those bikes make great HP to about 37+ with about 25+ FT LBS that's very good for a 125.

Click to expand...

Try 32-34 hp, and around 15 ft-lbs of torque.




Most manufacturers have jumped around on the number of gears on bikes. The main reason for going for fewer (6 to 5) is to save weight and make the cases narrower. If you drop a gear out you can narrow things slightly, make the remaining gears stronger, and shave a bit of weight. I think most 125's have jumped between 5 and 6 speeds, and 250's have mostly been 5 speeds. 4 strokes came along and 4 speed transmissions became very common.