xr400 bottom end vs 400ex bottom end

[bigballz400]

is the xr transmission different then 400ex??

can u put the xr kicker gear on the 400ex counter shaft, along with the kicker components with a xr case cover with quick change clutch??

[CJM]

I recall its possible, just alot of parts and time involved.

[dxcody]

The cover itself will fit im pretty sure. .

Pappy had one on his according to this thread. They say the frame hits.

http://www.exriders.com/vbb/showthread.php?threadid=269164

[bigballz400]

heard u gotta lenghten the lever for the clutch

im not so worried bout time, thats all i have and a six day a week job lol.

from wat i see u need the kicker shaft, spring and two gears, looks like the xr cover will hold both the kicker shaft and gear in place, there is a spot in the 400ex case for a shaft of some sort which im assuming is the kicker shaft

every xr bottom end ive seen apart jus show one gear on the counter shaft, so im assuming the rest of the components r gunna be in the cover

[BlasterEaten250]

I just researched this and it sounds like you need a xr400 clutch cover with a Hinson quick change cover. The stock quick change cover will not work with the 400ex clutch from my understanding. That is where I hit the roadblock, finding one of those Hinson covers...Then you have to find a year 2000 kick assembly and kick start gear to put on the back of the clutch. It really doesn't seem too hard it is just a pain to find all those parts if you aren't buying new.

[bigballz400]

how bout runnin a xr clutch basket and clutches to eliminate clearence issues

another question, is the trasmission the same, same gears ratio? or is the xr 400 got longer trans gears?

[ish416]

another question, is the trasmission the same, same gears ratio? or is the xr 400 got longer trans gears?

The XR has taller gearing and the gears themselves are not anywhere near as beefy as they are in the EX.

[dxcody]

Originally posted by ish416
The XR has taller gearing and the gears themselves are not anywhere near as beefy as they are in the EX.

Yep, they are quite a bit taller.

You can compare how much bigger they are if you get on motosport.com and compare 400ex OEM transmission gears and XR400R OEM transmission gears

Makes since to have taller gears on a dirtbike thats 120lbs lighter than the 400ex.

[jman7290]

Do you have to split the cases and change anything in the bottom end, or is everything done under the right side case?

[SpasticR450]

Look at the engine mounts. Not in the same spot. And why would you want to put a xr bottom end in it wouldnt it be easier to just put the hole engine in it?

I seen a 400ex engine once in a xr bike. Reason they did that was for woods racing revirse comes in handy.

[bigballz400]

taller gears, and get rid of half the electrical

but if the gears rnt as strong thats questionible on its own

[sc400ex_rider]

all the transmission bearings on the ex were improved for the increased load. 4x the tire contact patch on ex) the xr gear ratios are better than the 98-04 but very close to the 05+.

[SpasticR450]

100% wont work case closed. If your going to do somthing make it a hybrid. For years and years ppl been asking how to make an ex kick start. If you want anything from a xr400 take its cam its like a stage 1 hot cam to a 400ex.

[bigballz400]

yea i was gunna get a cam and head gasket.

but if it wont work , it wont work

[1krazyquadridr]

I would disagree with several of the comments. I have put an XR transmission in my EX, so I know that it can in fact be done. I also have kick start on my EX, so that can also be done. As far as gear strength, while doing the swap, the gears are of the same size and width, the only difference being gear ratios. I retained all the EX bearings with the exception of one due to shaft diameter size. I have run the XR gears in my MX 440 stroker without any problems. The gearing is great for 1st gear starts on the motocross track. The engine cases have different mount points, but otherwise the internals are nearly identical. I hope this helps a few guys out who arent afraid to give it a try.

[bigballz400]

so its a noticeable difference??, and which bearing did u have to get, bc i have several bottom ends id love to do something like that to!!!

more info the better thanks man!!

[CJM]

Originally posted by SpasticR450
100% wont work case closed. If your going to do somthing make it a hybrid. For years and years ppl been asking how to make an ex kick start. If you want anything from a xr400 take its cam its like a stage 1 hot cam to a 400ex.

Please stop offering advice when you clearly dont have a clue wtf your talking about.

[1krazyquadridr]

Ok, I looked back at my notes, and 3 of the 4 mainshaft and countershaft transmission bearings have the same Honda part numbers for both the XR and the EX. The exception is the countershaft bearing on the clutch side is slightly smaller on the internal dimension. As far as a difference goes, thats kind of subjective. For me stock first gear was too low to start a race, and second was just a little high. The XR gear ratio kind of split the difference. Plus there was the added benefit of having what felt like overdrive for 5th on the trails. I bought a used XR bottom end and everything just swapped over for the transmission change. While I had it apart I did the kick start too. It really is a straight forward process if you are comfortable splitting the cases. I hope this helps anyone out that might be considering doing a similar swap. If anyone doubts me, just go to cheapcyclepart.com and pull up the two microfiches side by side and you can see that many of the part numbers are identical.

[bigballz400]

thanks for the info!!!

[BlasterEaten250]

Originally posted by CJM
Please stop offering advice when you clearly dont have a clue wtf your talking about. Thank you.