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pmk

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About pmk

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    Advanced Member

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  • Bike
    OSSA MAR & SY250R

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  • Location
    Florida, USA
  • Gender
    Male

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  1. pmk

    smokey mar

    Agree. As I posted, after switching oils and getting tne pipe pretty hot, just sitting there not running smoke was coming out the pipe. Plug was fun. After it did its thing, smoke subsided.
  2. pmk

    smokey mar

    Agree with what B40 said. For comparison, my MAR, I had switched oils and all is good. However at a recent event, between the hill sections and immediate connector sections, my pipe was smoking pretty good. Laughing about it, we questioned if the bike was going to burn to the ground, which it did not. Merely residue built up from slower running. But do not rule out the oil seal, or retightening the case screws, though that should not be a concern with a fresh rebuild.
  3. pmk

    Footpeg Location

    Progress. Footpeg relocating also entailed relocating the kickstand. Been busy getting a lot done on this OSSA. Still getting messages that I can not post photos, otherwise I would.
  4. pmk

    OZO Rear Shock Question

    Sorry, a few posts touched upon what they are on. Bike is an 72 OSSA MAR. Overall though, removing the spherical bearings and replacing with vinyl tubing got them mounted with no concerns regarding installation. However, open to hear what other ideas you might have that could be better.
  5. Emulsion shocks run body up...Yes, you should be ok. My own MAR runs period correct Curnutt shock, bodies up, shafts down and are emulsion type. I would say, but have not tested these shocks as emulsion shocks. I suspect that what I have seen with these shocks, if you ran them as emulsion type, you could also not gas them since the sealhead is clamped between the clip and the end cap. No doubt gas pressurized performs better, but no pressure makes seals last longer and less likely to leak.
  6. I modified the IFP with a bleed hole that is sealed with a sealing washer and screw after the shock is bled and IFP position set. I serviced the fluid from the top since I removed the upper eyelet from the shock body. If you do not modify the the IFP, you could position the IFP to the proper depth, then do not insert the seal into the counterbore. The excess fluid will leak past the DU bushing until the sealhead seats on the circlip. Insert the combined oil / dust seal and install the end cap. As for softening the damping, I installed a bleed shim between the single main shim and piston face, plus altered the far side clamp diameter by adding a small shim above the machined aluminum seat. Used Motorex 2 1/2 wt fluid. Yes I know it says fork on it but it is also a very good rear shock oil. Also, while apart, everything was deburred, and the shafts were polished. I went a touch lower than typical gas pressure at 125 psi, but was higher than the 60 psi in one and 80 psi in the other shock from the factory. These shocks now will extend freely, and so far, when installed, the bike feels good and returns to static height. As I mentioned before, not bad shocks for the money, the price point seems OK for two shocks with springs. The real question will be are parts available?
  7. pmk

    Footpeg Location

    Unladen. Even my stock footpeg location MAR, when riding the footpegs are below axle centers.
  8. Ironically, expecting an internal bladder, I was super cautious on disassembling the first shock. Once I saw the internals, the second was apart in minutes. No bladder lessened any likelihood of damage while working on them.
  9. pmk

    Footpeg Location

    Progress was made, Footpeg structure for the frame mods has been fabricated and installed. Footpegs are no more than 5mm above the axle centers. The pegs were not moved forward or rearward as best we can measure them, and if they have move it could be rearward a mm or two. Everything is aligned so the pegs are parrallel to the swingarm pivot, same distance rearward, outboard ends are slightly up and footpeg tilt is level front to rear and match within 1/2 degree side to side. Material used to make the parts was 4130 chromoly steel, 1/8" thick. forward curved edge is welded to oem frame, the other edges are bent / flanged then welded to give side load support. We did not box the backside. Certainly would be stronger. Do not consider it needed, but time will tell. It will see cheap paint to sort out any issues before taking it apart again for powdercoat of the frame. I would post a photo but I must be maxed out since no more photos can be posted.
  10. Kind of comical...the advertising says "internal bladder technology" however, there are no bladders inside these shocks. In the photos, kind of holding the pose for the OZO sticker on the upper shock eyelet / endcap you can see the two O rings per IFP and the IFP separator pistons under the endcaps. So no bladders, but there are aluminum IFP with dual O rings to keep the gas and fluid separated.
  11. I tend to agree somewhat, but not always. These would have been difficult to ride at the event as they were and not broken in / freed up. At this point, after the event, if more changes need to be made, it is an easy task. Honestly though, at this point it was a good choice and my buddy can bring his previously ridden Betors in case he decides to swap back.
  12. As feetupfun mentioned, a fiddle with the damping. Yes, correct, this all started with my friend buying these OZO shocks for his MAR. Initially, there was concern removing the upper eyelet mounting bushing setup as shown in another topic. He installed these OZO shocks onto his MAR, replacing aftermarket Betor shocks he purchased a while back. The Betors were pretty firmly damped, actually overdamped and had a design that did not allow easy removal of the coil spring. The OZO shocks were purchased with intentions to fit his second MAR, the one being modified with lowered footpegs and more, again, the reason for yet another topic. We have an event this weekend. My buddy wanted to run the OZO shocks on his current MAR, the relatively stock bike, not the one we are moving footpegs on. So after getting the mount setup sorted, he installed them. Yesterday he came by my house to check that the OZO setup would be good. He rode the bike about 10 minutes and I rode it a few minutes. After I rode it, I told him they were over damped, ultimately, he accepted that in this application they were over damped. What you see in the photo, his shocks, pulled apart. I made some valving changes and redeveloped how they are assembled allowing both shocks to be easily worked on, with repeatable assembly setups that match the left and right shocks performance. Initially, the intent was to merely swap the fluid for something with less viscosity. Finding the viscosity of the fluid fairly thin, other options were utilized to accomplish the goal. Nothing difficult, merely took a good base to work from and made a few minor setting changes. Once together, he was able to again ride the features at my house. The changes were in my friends own words “night and day difference”. In simplest terms, the compression was softened and rebound quickened. Not to the point of change to be like a modern bike all springy and hoppy, rather to follow the ground and features better with more control. Obviously not something everyone should delve into. The photo is merely to share information about what is inside. Realize also, I have the proper tools and experience to do this. Being old, I have tuned many shocks and forks since I started working on suspension in the mid 1970s. These shocks should prove to be a very good setup for him. My hope is seals are maybe available, plus if needed other parts too. Start to finish the entire job took about 2 hours. The first one coming apart was slower in disassembly, to understand how these were assembled. The second one was apart in a couple of minutes. We did take the added time to hand finish typical edges to make reassembly and performance smoother with less likelyhood to cut an Oring. In simple terms, these are now blueprinted as we call it in the USA, the pistons valving was changed, shafts were smoothed and polished, and the fluid in them now is a known item, easily attainable. Not bad shocks for the money, just needed a bit of attention to be what was needed for his bike and riding.
  13. A look inside the OZO Pro shocks.
  14. pmk

    Footpeg Location

    Agree. At the moment, I want to ensure the new brackets are true. The tacked on peg mounts are so we can ensure the pegs are not droopy or angled forward or aft. Once that stuff is welded, I will probably do something similar to what you mentioned to attain the height and tilt to be positioned correctly. None of it is difficult, just time, and best to do right the first time.
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