XR400 and 400ex tranny

[oynot400]

Well I had a slight failure yesterday. I lost 2nd gear. :( No biggy just tear it down and put in new. I was checking out if there was any difference between the XR and EX trannys. I was noticing that they have different ratios for their gears. Has anyone tried putting in xr gears in an ex? :confused:

[YZROOSTINYA]

the xr is gonna have taller gears since it is a dirtbike. aslong as they are the same and just the teeth are idff you should have no prob. i always thought the ex gears wear beefier

[oynot400]

Any one else? :ermm:

[shaneb]

how different are the gear ratios ???

do you have a link to the info on the ratios for the xr and the ex ???

Shane

[oynot400]

I just went to www.rivaracing.com and looked up the part #'s. It gave the number of teeth for each input and output gear. So I could figure out the ratio. They are different, the xr's are taller gears. I need to find out if they will fit on the shaft. My plan is if I gear up 1st gear, then I will not have to worry about starting out in 2nd. I was also told that 5th gear is changable also. This will help out on top end speed. I just don't know if they are interchangable or not. :confused:

[250x#93]

Sure why not:D

the ex gears are beefed up

[YZROOSTINYA]

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2405325554&category=10066

a gear set on ebay cheep, buy it up

maybe you can get a xr gear set and get it hard anodized to make them stronger??????

[MIKE400EX]

Hopefully you can't anodize the gears, since that's for aluminum and magnesium alloys. Carburizing or heat treating might work for steel gears. A taller first gear would be good though!

[YZROOSTINYA]

whatever its called , thats what i meant

[Bill Fuller]

the tranny in the ex has got to be the weakest part of the whole bike,I have blown mine and know of countless others.Is the after market not producing anything stronger? Just waiting for this to happen again:mad:

[MIKE400EX]

YZROOSTINYA, wasn't meaning to "bash" you for saying that. By-product of the job. I get people calling weekly, that are making aircraft engine parts, saying that. THAT scares me! :eek2:

[Sick0]

I blown second and thrid.

[YZROOSTINYA]

got ya,

I was just spitting stuff out and didn't feel like looking it up, I understand where your coming from:D

I knew that anodizing referred to aluminuminum, but firgured he would get my jist.

I know there are companies for the raptor and such, maybe they make gears for the fo hunded also?

[oynot400]

I just got off the phone with Sparks, just to see if they have done anything with it. They build their engines so you can start in 2nd gear. I still think I have a cam issue that is stopping me from doing that. :( May be I could get the gears cryo-treated to help strengthen them.
Thanks for the ebay link YZROOSTINYA, I might check into that. I will let you all know what I find out.
Thanks, :)

Oynot..call Al Baker at XR's only..I'm sure he knows for sure what you need to do and what options are available...:D

[MIKE400EX]

OYNOT400, If it's because you don't have enough low end torque, check the cam timing. It may be retarded. You can always advance it 2-4 degrees over base to gain some grunt.

[oynot400]

Thanks for the tip Rico, I called them today. They told me that the bottom end of the motor is different between the ex and xr. They said that it will not work. I told my Honda dealer what I wanted to try. They did not know either but was willing to order the gears that I wanted and if they did not work would take them back. It sounds like I should know right away, they will either fit on the shaft or they will not.
I do believe the reason I am having problems with 2nd gear starts is the lack of bottom end torque, due to the cam I have. I am suppose to call Mike at FDO tonight and we are going to go over my cam specs and pick a different cam if needed.
Thanks guys.........:)

[oynot400]

Well guys I am more confused now then ever. I got a XR400 manual at the Honda shop to look at. According the specs it gave the shaft size should be the same. Now taking in consideration of the gear ratios, I am wondering if I do change 1st gear and make it taller. That will make 1st and 2nd pretty close together, right? So in return that will make 2nd nearly useless. Costing me time in another shift.
I am going to degree the cam next week and see what I get out of that before I go and change the ratios.
Thanks for all the help.......:D