jfisher304

Member
Nov 15, 1999
103
0
I have a question about the YZ and WR 400 transmissions. I recently converted my 98 YZ 400 into a street legal supermotard, but the geraing is eating me up. If I have it geared "normally" it has nowhere near enough top speed. If I gear it to run 70 mph or so at reasonable revs, I am having to dog the clutch to get off a stoplight. I rode a friends WR based motard, and it was much better. Is it possible to put the higher 5th gear from a WR into a YZ tranny. Or is it the other way around where the WR has a lower first gear? Anyway, I don't see spending the mucho $$$ it would probably take to do a complete tranny swap, if I could even find one somewhere. If I can just replace some of the gear sets though it would be worth it.

Thanks,
Jason
 

Humai

LIFETIME SPONSOR
Feb 6, 2000
199
0
Here are the ratios FYI:

WR400F (1st to top)
2.416
1.733
1.312
1.050
0.840

YZ400F
1.929
1.563
1.278
1.091
0.952

So, the answer is "both". There are guys lurking around that have interchanged gears on these bikes.

That bike of yours must be a blast to ride on the road! Good luck.
 

jfisher304

Member
Nov 15, 1999
103
0
Well in all honesty I don't have a tach on it, so I am just going by what feels about right. The tallest gearing I have run on it is 15 / 44. If I could first gear down low enough I would leave it, if I have to switch 5 th gear out I will go to 15 / 47 maybe 48. When I am runnig a short course, or just goofing off I switch to 14 / 46. The bike is tons of fun on the road, and I feel much safer on it than I ever did on a sport bikes. I have had to run the thing off in the ditch at 70 mph to miss idiot cagers on the freeway, and this morning I had jo jump a curb to miss getting hit. In both cases I would have probably gone down on any other bike. I just hope I can get the gearing sorted, if not I will just keep it this way for a year or so, and look at converting one of the Honda 450's when they come out with their WR version. Thanks of posting the WR / YV ratios, that will at least get me started.

Jason
 

Humai

LIFETIME SPONSOR
Feb 6, 2000
199
0
Jason, let us know how any gear swapping goes.

My '98 YZ400 has assumed the role of a part time "dunes bike". Access to the dunes is by way of a 15 mile or so cruise up the beach at low tide. I'm running 15/49 gearing and my cruise sweetspot is about 90km/h (about 55mph) with this. I'd estimate somewhere around 6,500 - 7,000rpm at this speed.

The bike still does duty in singletrack but is a bit of a pain in the really tight stuff with that gearing and the lack of flywheel.
 

jfisher304

Member
Nov 15, 1999
103
0
If I can ever get it done, I'll be sure and post the details, but as of yet I have found no one who can give me the details of gear swapping. I personally have no buisness trying it all on my own as I have never even split my own cases, and I don't wanna let my local shop do it as it would be trial and error on their part, and I would get charged by the hour accordingly. The only thing I can get out of anyone is that they heard you could just swap the 4th and fith gear sets. Not just 5th by itself. I have e-mailed and or called alot of four stroke specialist and all they can tell me is that they have heard of it being done.....................oh well.
 
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