200x 6 speed conversion question. What years work?

[trike savior]

planning on picking up 6 speed transmission set from xr200 for my 200x project. have done my research on here and also found info on .org a while back. only info I cannot find is what years donor transmissions work. set I am looking at is from 84-85 which is the few years for the RFVC 4 valve motor and not sure if that makes the bottom end different. any info from people who have done the swap would help.
thanks
jon

[oscarmayer]

i hate to say it, but do a search. there has been 5-7 different threads on this in the last year nad there is a ton of info for ya.

[trike savior]

looked through them all. I have seen the fights about them being weak and needing to use the smaller xr kicker gear on the x kicker. but no one says definitively what year transmissions work or even what year they used. I am not a newb that was too lazy to search first. if you know of a post with info I might have missed, please share.

[oscarmayer]

^haha yea true. I do know this, It seem that matching years seem to work best. So for example, using a 85 with an 85 seems to work fine and so forth.
Some guys claim thickness of material and gear strength, but unless your building a built to the hilt power stroked, john slider his shaft, chicken stalking choker motor. I would not really worry too much about that. even with a 12:1 Weiseco, cam and valves, you should be OK.

[trike savior]

I have also been researching using the bigger xr carb. I am trying to find if the larger xr200 intake bolts to the 200x head or if you have to run the xr200 head as well. still searching but if someone knows please chime in.
(update: found a post by dirtcrasher saying xr carb/intake bolt to x head)

one of the posts I just found on that topic said 80-83 xr bottom ends are the only ones like the 200x. however top ends are the same 80-83 and 86-02. can anyone confirm the 80-83 trans is all that works?

[Toaster556]

I can 100% confirm the 80-83 and 86-02 XR200R trans being totally interchangeable.
However, there is an XR200, not R, that has a different, lower first gear, at 3.083 rather than 2.769 found in the XR200R. A guy I rode dirt bikes with tried it in his Powroll 218, hated it due to the awkward jump from first to second, and went back to the R trans. The XR200A can be identified by the twin shock frame, but otherwise, it's a guesswork on ebay.
A good resource for anyone building an 83-85 200X is a guide compiled by a British chap called "On The Problem Of The XR200". It mainly deals with building an XR200 motor out of an XL125S or XL185 in England, due to Honda not importing them, but contains a great deal of measurements and interchange. It's found HERE or in PDF format by googling the title.
I won't say anything about strength or durability on here, but I've stated personal experience on another thread. PM me for any further details or questions on it, or why I believe what I do regarding the trans.

[YTZ drew]

The RFVC models are the only ones that won't work, but as Toaster says, the super-low first ratio really is lousy. I have the very XR200 twin shock he speaks of as one of my main riders, and on certain trails, first is way too low and second is too high. For what it's worth, xL200 bottom ends work too, but I think they have the low first gear.