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1984 Xr200r rfvc rebuild. How to...PLEASE HEEEELP!

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So I got a great deal on this old girl...and boy...did she need help. After draining more water than oil out of the engine and removing.all the leaves and pine needles from the case...I find that most of the case bolts have had odd ball bolts stuffed in it...as well as the head...I want to start fresh. I have an enormous access to 200x parts from all years. I know the trannys are stronger with the X but my engine is 4 valve and 6 speed. Only X's in 6 speed are 86/87. But believe they changed motor mounts for the atc in those years from.first gen. So if first gen motor mounts are same as 84/85 xrr mounts am I safe to say the mounts won't line up from 86/87 X? Will cases work on my xrr? Is there any way around walking out of this without spending an arm and a leg? Anyone have decent factory cases? Head? And if I do &%$#@! it all and send my left nut to the slaughter house...what upgrades should I do to keep this 4 valve running for another 30 years?? Ani info helps...I can get an engine.missing cam and rockers for 300 shipped but would need a rebuild on top. Other than that...I'm at a loss! Take a chance with this mismashed case and rebuild this pile?(which I do not trust or want to do!!!) or bite the bullet and spend big? Or is there any saving the idea that my precious supply of atc parts will work?? Thanks

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Completely different motor.  You could probably use the whole engine with new motor mounts though.  I don't think any of the ATC 200 engines were compatible with the 4valve motors.  XR250 engines are probably your best bet for parts.  Hopefully someone with more experience in the 4valve 200 will chime in though.

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The 4 valve motor is totally different. None of the two valve parts will work. Two valve motor does not fit in 4 valve frame. 4 valve parts are harder to find, but you can usually find what you need if you look hard enough.

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All of the above.

Since the XR200R 4 valve motor is based on the 84 XR250R 4 valve motor, which with some changes was used thru 95. Check a online part fiche to compare part numbers.

A 84-85 XR250R top end will bolt on, a 84-85 XR250R motor will bolt into the frame.

A 86-95 XR250R motor will also fit the frame but you will need the carb, airboot, and oil cooler (or make a bypass).

in 86 the XR250R went to a smaller bore and longer stroke so one mod was to use the big bore 84-85 cylinder on the later motor.

RFVC engines w/ model codes (stamped on left side of engine):

Model................. Model Code.. Bore.. Stroke.. Displ
XR200R 84-85 RFVC.. ME05.. 67...... 56.5.... 199
XR250R 84-85............. ME06.. 75...... 56.5.... 250
XL250R 85-87............. ME06.. 75...... 56.5.... 250
XR250 86-95............... ME06.. 73...... 59.5.... 249
XR250 96-04............... ME08.. 73...... 59.5.... 249

 

Model code ME05 also used on the 86-02 XR200R two valve motors.

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Most people swap to 250 motor period. And myself and a few others hate the twin carbs as parts are hard to find and tempermental. The twin carbs did run great when everything was good though.

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I've been looking around. The 84/85 xr250 motor is even more than the 200!! So I think I'm going to go with no cases and use my internals. Can't seem to find a good head though...this is getting pricey!!

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Bad joke by Honda using the same Model Code for bikes with two very different engines, but I understand because the chassis were the same from 84 and on (except for the motor mounts).

 

XR250R engines thru 95 will fit the 84-85 chassis, and most of the engine parts will also fit the 84-85 engines. Post no 5 has bore stroke info.

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Ok...so I finally found a decent complete 84 Xr200r to use the parts bike to fix up. After I whiz wheeled the cam and sprocket off(someone snapped the cam at the sprocket mounts and decided welding was a great idea) got the new donor cam and sprocket and timing.chain in...I noticed that the engine from the parts bike had the oil drain plug on the shifter side of the case. The engine on the bike I'm putting together has the drain plug on the bottom...any ideas?

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