modified 5th gear... check it out!!!!

[trx250racer]

i found this in an 86 bottom end that recently opened..
check out 5th gear on the counter shaft, can anyone tell me why it has been tapered the way it is? it has been done to the one gear. gear is not worn out or have any grind marks on it. it looks like it has been machined.
any help would be nice.. thanks in advance!!!

http://i1085.photobucket.com/albums/j438/TRX250RACER/gear002.jpg

http://i1085.photobucket.com/albums/j438/TRX250RACER/gear001.jpg

http://i1085.photobucket.com/albums/j438/TRX250RACER/gear003.jpg

http://i1085.photobucket.com/albums/j438/TRX250RACER/gear004.jpg

[Honda 250r 001]

I cant see the picture for some reason. But i have a gear that has the same thing done to it. It was machined down. I never knew why it was machined but I kept it, just incase it was for some special tranny set up.

[atvmxr]

cant see pic, but assuming its had the dogs machined down some to allow for better engagement - what we call back cutting a trans on zilla motors.

not to be confused with undercutting a trans or the other mods for drag racing

[Honda 250r 001]

I believe he may be talking about the actualy splines/teeth of the gear. Or atleast thats what part of my gear has been machined down.

[destey]

Did the guy try and turn it into a helical gear?

http://upload.wikimedia.org/wikipedia/en/d/d1/Contact_line.jpg

[trx310R#24]

iv had lot of motors that had this done... i think on newer bikes some of the gears come like that

[86 Quad R]

Originally posted by trx310R#24
iv had lot of motors that had this done... i think on newer bikes some of the gears come like that

i seriously doubt it but i aint seen it all either. :cool:

[wilkin250r]

Originally posted by atvmxr
cant see pic, but assuming its had the dogs machined down some to allow for better engagement - what we call back cutting a trans on zilla motors.

not to be confused with undercutting a trans or the other mods for drag racing

No, it's not the dogs, it's on the teeth.

It looks like it might have been machined to fit underneath the gear next to it, like one or the other might not be the stock gear, so some machining had to be done to get it to fit.

[rubbersdown]

Originally posted by 86 Quad R
i seriously doubt it but i aint seen it all either. :cool:

Hes right, I have a 400ex, crf450 and a yz450f tranny in my garage right now and pretty much all newer bikes have the higher gears cut like that straight from the factory.

[86 Quad R]

Originally posted by rubbersdown
Hes right, I have a 400ex, crf450 and a yz450f tranny in my garage right now and pretty much all newer bikes have the higher gears cut like that straight from the factory.


interesting. but, i a s s umed he meant the new "250R engines. :rolleyes:

[C41Xracer]

I see it, i got a set of gears like that from baldwin but 2-6 were like that. Mark claimed it helped with gear engagement, this helped gear breakage

[trx250racer]

can everybody see the pics?

[Honda 250r 001]

Originally posted by trx250racer
can everybody see the pics?

Yes i can see the pics now. Looks exactly like the one i have. I wonder if it really helps any?