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About pmk

  • Rank
    Advanced Member

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  • Bike
    OSSA MAR & SY250R

Profile Information

  • Location
    Florida, USA
  • Gender
  1. Ossa MAR alloy tank.

    Not sure which tank you purchased or from what vendor. Simply a FWIW, my buddy purchased an aluminum tank for his MAR. While it looked great, with use he found the tank had a couple of small leaks along the welded edges. The guy we use for welding is aerospace certified. He spent some time welding the tank and would smooth the edge back as it was with no bead of weld showing. Try as he might, the seam would open slighly in another spot. Point being, it appears the edge is a very thin joint after being sanded smooth. Ultimately, I asked our welder to do a nice functional but pleasing to the eye bead around every seam. Once polished the tank looks fine.
  2. 73 Mar 250 gearbox

    In regards to OSSA parts, I have been buying from Alex Snoop in New York. Alex has been great to get stuff from. He recently rebuilt my friends MAR crankshaft, that engine will be going together this fall.
  3. Show Me Your Twin Shocker!

    In regards to the Preston Petty fenders, I have been talking with the current owner of Preston Petty Products for a long while now about various topics. Currently, the fenders are not available, but are on the list of things to be offered in the near future. Currently they are selling the MX Front fender which is the old Tony D, the mx rear, the enduro rear fender with light and without light, the headlight, and I believe the front fender with integral bracket to mount to the underside of the lower triple clamp. The modern day Preston Petty Products are molded by Polisport for PPP. The molds and tooling are expensive, but the quality is supposed to be very top level. If I remember, I will share when the fenders are released and ready to ship.
  4. OSSA fibre glass tanks.

    Typically, the resin used is Vinylester. Here in Florida, where boats are common, this resin is easily obtained locally and the cost is not expensive. Currently, I am helping my buddy repair two oem MAR tanks. He has been doing the sanding, and I have been doing and teaching him the glass work. When he returns to Florida this Fall we will finish them. No plans to coat them, but one maybe both were coated previously. To find the leaks, I used a bicycle pump on the tanks vent and sealed the cap with a section of flat rubber. Submerged in a bucket of water, I added a couple PSI slowly with the bike tire pump. As for the aluminum tanks, my buddies MAR currently has one of the Spanish aluminum tanks on it. He bought it new, and from day one it had a leak. Not bad, but it was on the upper seam. He rode it this way a while and just recently had it repaired. Our welder guy is a certified aerospace welder. Even when super cleaned, he commented that the aluminum is a bitch to weld as the original welding was kind of dirty. Ultimately, this aluminum tank was welded with the beads left and not sanded. Plan is to mirror polish it and hopefully not dent it.
  5. Gripper timing

    Interesting, but are you certain retarded timing causes backwards running. I was always led to understand if the timing is too advanced, the engine kick back and provided the kickstart is not engaged, this is the initial engine firing that sets in motion the backwards direction. After that, the timing is firing after top center, and look out when you let the clutch out.
  6. Show Me Your Twin Shocker!

    Photo did not post. Was this the orange bike in Missouri, USA.
  7. Sy cylinder head removel

    Until filled to the top, then the excess will purge out the radiator cap.
  8. Sy cylinder head removel

    Try the Fowlers website for the TYZ, that's your best bet. I assume you are referring to the letter code. Most times, if it is the first piston swap use a B, but they may go as high as D.
  9. Sy cylinder head removel

    Thought you were selling the bike. Seemed like it was sorted out, what happened.
  10. Air/Idle Control Problems

    I agree with FeetUpFun, make certain the carb is clean. These bikes do not like any debris in the carb or jets. Next, ensure the throttle and cable are rigged correctly with a small bit of freeplay in the grip with throttle closed. I will add, my own SY recently had some weird stuff happening. Turned out to be the rubber disc in the choke plunger had fallen out of the brass plunger. Not lost, but would randomly reposition itself, the bike ran pretty good, but would die on any descent.
  11. Sy cylinder head removel

    Reading posts here on TC, I was under the impression that one of the mods done to these bikes was replacing the cylinder studs that secure the head with bolts. This was done so the cylinder head could be removed with the engine in the chassis.
  12. Silencer repack

    I have been looking for it, just no luck yet.
  13. Silencer repack

    Somewhere on the internet, there is a set of photos about accomplishing this. I thought they were linked on the laptop but apparently not. I searched quickly with no luck. I think the guy is from Italy that did the repack.
  14. MAJESTY questions

    Always liked the looks of those bikes. Never seen one in person and not even sure if many made it to the USA. How do they compare to the production bikes of the same ERA, such as the TY and MAR, plus more.
  15. Best Levers

    Agree, the OSSA requires the cable be cleaned and lubed constantly, and typically. Most times this is done the day before an event.