83-85 200X Rear Master Cylinder Swap (LTZ400/KFX400)

[Kryten]

My ’84 200X I recently bought needed a replacement rear master cylinder since the original was in poor condition and a rebuild kit just wouldn’t do any good. After searching the forums I came across mention of the LTZ400/KFX400 swap. This seemed like a good way to go since these parts would be about 20 years newer and less expensive. I only found one thread with some detailed information for the 85/86 250R so I took a chance and bought a 2003 KFX400 rear master cylinder assembly that included both hoses and reservoir. Here’s my experience with going this route.

First step was to turn the threaded holes in the master cylinder body into clearance holes for the mounting bolts. Next I used 5/8” long spacers to locate the unit away from the frame due to the design of the LTZ/KFX master cylinder body which also required longer bolts. I also had to rotate the tube connector so it points up (the one that connects the master cylinder to the reservoir) to clear the frame. I reused the brake rod joint from the 200X since it’s shorter than the LTZ/KFZ joint and connected this to the arm in a slightly different way due to the offset (see pictures). I retained the 200X reservoir due to mounting issues with the LTZ/KFZ version, although you will need to heat up the hose to allow it to stretch onto the 200X reservoir connector.

If you go with a LTZ/KFZ master cylinder I suggest purchasing a unit with both hoses to avoid difficulties due to hoses being too short. I still need to address the brake pedal height, right now it sits too high, but this should not be difficult to remedy. Besides that I am satisfied with the outcome, newer parts and less expensive.

I imagine you could also use some kind of adapter plate for mounting, but this method will definitely work.

http://imageshack.us/scaled/large/191/x84q.jpg (http://imageshack.us/photo/my-images/191/x84q.jpg/)

http://imageshack.us/scaled/large/18/0ha5.jpg (http://imageshack.us/photo/my-images/18/0ha5.jpg/)

http://imageshack.us/scaled/large/689/bvy1.jpg (http://imageshack.us/photo/my-images/689/bvy1.jpg/)

http://imageshack.us/scaled/large/853/twrt.jpg (http://imageshack.us/photo/my-images/853/twrt.jpg/)

http://imageshack.us/scaled/large/716/hp9t.jpg (http://imageshack.us/photo/my-images/716/hp9t.jpg/)

http://imageshack.us/scaled/large/716/1w79.jpg (http://imageshack.us/photo/my-images/716/1w79.jpg/)

[zagames]

Very nice work Kevin! Looks great!

[duck4twenty]

just got this one off amazon for 18.00 bucks 190941190942 its pretty close just had to widen the mounting holes and shorten the push rod. Will post more pics when finished




www.amazon.com/gp/product/B00H40T65Y/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1

[big specht]

I wounder if the new one has the same size bore? As the oem one?

[duck4twenty]

here it is mounted up,191175191176191177191178
just waiting on cr85 caliper and longer brake line, the old brake line would work fine but i have a +6 swngarm using my front brake line to test but my old caliper is leaking so cant really tell

[duck4twenty]

just installed 03/cr85 front caliper for my rear 84 200x brake setup & and replaced my oem front master cylinder with the cr85 since i got the whole cr85 front brake setup might as well. Took me awhile to bleed out all the air but i got it out. Now for some hill climbs and i could ride on the more difficult trails.