1983 ATC200X basket case resto-mod

[1stGEN110]

I’m curious if anyone on TWW has any experience with the adjuster needle orings on a 200X shock. In retrospect I should’ve done the suspension work myself, I could’ve tried and screwed it up a dozen times at this point and come out ahead on my time and the whole project being done. Unfortunately, I have never disassembled a shock and I certainly didn’t disassemble this one either, usually with enough time I can figure about anything mechanical out by reverse engineering the assembly.

If the tiny oring in the shock shaft that seal the needle are supposed to be under high pressure, would anyone here be willing to share some insight on how the needle and shock shaft go together? I have a factory service manual and can get the rest of the shock together.

[Footy]

I’m curious if anyone on TWW has any experience with the adjuster needle orings on a 200X shock. In retrospect I should’ve done the suspension work myself, I could’ve tried and screwed it up a dozen times at this point and come out ahead on my time and the whole project being done. Unfortunately, I have never disassembled a shock and I certainly didn’t disassemble this one either, usually with enough time I can figure about anything mechanical out by reverse engineering the assembly.

If the tiny oring in the shock shaft that seal the needle are supposed to be under high pressure, would anyone here be willing to share some insight on how the needle and shock shaft go together? I have a factory service manual and can get the rest of the shock together.

The nitrogen pressure should be in the reservoir.

[1stGEN110]

Yup, I totally get that! The issue is apparently instead of the oil going through the orifices to dampen the movement applied to the shock, they are taking a path of lesser resistance through the shock shaft bore and out of from behind the clicker knob when the shock is compressed. This is when actuating the shock by hand with no spring installed, I’m sure it’ll create even more resistance to fluid flow at higher loads and speeds than I can induce by hand. Basically, I’m wondering what keeps shock oil sealed away from the inner shock shaft bore where the clicker needle lives? Thanks for the reply!

[1stGEN110]

The rebound adjuster needle has a large groove closest to the adjuster knob, I believe this to be a secondary seal point and the main locating point for the needle. The needle itself appears to float in the shock shaft bore secured only by the oring pressure. The small step down towards the tapered end of the needle appears to be the primary seal point. I’m guessing that’s where the bulk of the hydraulic pressure is held back.



Upper end of the shock shaft, I believe this oring groove is the primary seal to hold back fluid pressure inside of the shaft.



Bottom of the shock shaft, yoke that attaches to the swingarm. This oring groove I believe is the large cross section locating oring groove that holds the needle in place and acts as a dust seal/secondary seal.




Finally gave up on the local suspension shop, in retrospect, I cannot believe I left my stuff there for a total of 10 months… insanity is doing the same thing repeatedly and expecting different results…

Anyway, after studying the internal shock shaft bore for about 3 minutes I see that there are two oring grooves as opposed to the single groove the shock mechanic appeared to be fixated on. The lower groove is rather wide in its cross section and it corresponds with a groove in the rebound adjuster needle which I assume like likely there for locating purposes, secondary sealing perhaps.

The groove I think is the primary sealing location is located approximately 1.5” down from the top of the shock shaft. The tolerances/clearances are pretty close and replacing the orings will be a challenge. But just the same I intend to try before sourcing another shock shaft/yoke assembly.

If anyone has dealt with these orings before or has any insight into what size the orings are I’d be all ears to hear. I had the owner of Schmidty Racing return my call last week to tell me in all of the ATC rebuilds he’s ever done he’s never seen a leak from this point. Lucky me…. 😁

[1stGEN110]

No one has any experience with these rebound rod orings?

[1stGEN110]

Progress! I bought a complete shock off eBay, it’s an 85’ 200x shock based off the ad and the blue spring. Surprisingly the coil diameter and wind is exactly the same as my 83’ non linkage shock.

[1stGEN110]

Making very good progress on the 200X, I have a complete rolling chassis with brand new bearings all around. Brand new tires, handlebars, plastics, seat cover yada yada yada. I am addressing the brakes now, in an effort to keep this bike all Honda I’m rebuilding my calipers and rear MC. I plan to use the more modern front MC off the CRF230 donor bike.

Question, my big caliper slide pins on the front and rear were a nightmare to remove. Corrosion had them all but seized in their bore. To the old timers out there, are these steel “liners” or “sleeves” supposed to remain in the caliper? I assume the take up any clearance between the caliper pin bolts and the caliper itself. Sadly the sleeves are not depicted in the parts diagram. I’d greatly appreciate any insight on whether or not I should try to get these off the old crusty caliper slide pins or just forget them and put in the new Honda pins I ordered and don’t look back.

Thanks!

[1stGEN110]

Follow up to my last post, for those that it may help. You definitely need these sleeves/bushings, they should stay in the bore of the calipers. My big caliper slide bolts were so seized and corroded that the sleeve and the big pin had essentially become one. Fortunately, utilizing some light heat from a torch did just the trick! They came off my old janky caliper slide bolts with little effort. I cleaned them up with a steel brush inside and they are going to be perfectly serviceable. The amount of play that was present between the caliper body and the new slide pins without the sleeves was excessive, over .050” but with the sleeves they are nice and tight! Another issue sorted out!




I used a 1/4” drive, deep well 3/8” socket as a die to slip the deformed bushing over and a little light work with a ball peen and you’d never know it had a defect.

When cleaning up my old caliper pistons I noticed the front brake piston had some minor corrosion on the forward edge of the piston, the rear was even worse with sizable pits in the side of the piston that would surely cause leaks and loss of brake performance. I erred on the safe side and ordered new pistons for both ends. I want to fix this bike once and ride it for the rest of time!

Once the pistons arrive I’ll get the brakes installed and bled, then it’ll be time for an engine swap!

[camy]

THIS BIKE IS KILLER!!!!!

[1stGEN110]

THIS BIKE IS KILLER!!!!!

Thanks for the kind words. Work, family and life in general has delayed me from finishing this build on the time table I initially hoped to. However, I have continued to make progress on it. The exhaust is done now, I used an XR’s only header and a NOS WileyCo chambered muffler along with a custom midpipe to complete the exhaust. I recently bought a TIG welder and I’ll use it to weld an O2 bung into the header to fine tune the jetting.

The frame had to be altered to use the physically large pumper carb I chose, the frame mods are done and I don’t see any sacrifice to strength the way that the frame tube was repositioned and rewelded.

The v.5 3D printed intake manifold is also done, to reinforce the composite material a rib was added to the upper portion.

I have a handful of customer bikes to finish up before I’ll be able to see the 200x through, but I’m very excited to get back on it and finish it up.