pmk

They have been great to deal with.

Wanted to add, I think the guy in NZ is looking for a later OSSA rear wheel setup, suspect he plans to run a rt side brake setup. Also, saw photos of different rear wheels fitted to the OSSA MAR, allowing all RT side brakes.

I have seen photos only, never rode it. In simple terms, a giant "C" shaped brake arm was installed to replace the short cable housing pusher arm. A rod ran from the top of the "C" to the rear wheel.

I did some research into the KX footpegs. I do not beleive that the newer KX pegs will work. The year range seems to be from 98 to 2000, but may be a year later. I threw away my notes, but they were based on what was currently available on EBay at the time. I got model year 2000 KX250 pegs, my riding buddy got 98 KX 125 pegs. At first I thought this was not going to work. The OSSA has 8mm bolts to secure the pegs to the frame. The KX uses 10mm pins. I have not installed mine yet but will as the machine is reassembled. My friend installed his immediately. His comments were the pin hole is a non issue, as the pegs sit proper with no drooping. He did mention the front cleat sets ever so slightly lower than the rear cleat, so front to back is not quite horizontzal. It could be possible to acheive level, then redo the cleats if desired. As for trimming, the KX peg has a flat plate that rests against the KX frame to support the footpeg, the MAR does not support the peg that way. This flat gets trimmed off and allows the KX peg to rest against the oem MAR design to keep the pegs level / flat. The KX pegs also have a limiter to control how far they fold. These my friend ground away. When I accomplish this on my MAR, I will post some photos. In the USA, these pegs are common on EBay for about $20 or less.

Beyond the silliness, the OSSA now runs well. After the flywheel and crank issue, I suggested run it a bit then lets ensure the flywheel remained tight, but also since the case screws were loose, we should check the clutch nut and cush drive. Yesterday, checked flywheel, verified no issues, but did remove nut and retorque with fresh loctite. Countershaft sprocket was loose, tightened it and folded the tab washer. Also rechecked center case screws were tight. All good. Removed clutch cover, no cotter pins on the clutch spring nuts. No issues and not surprised. Removed clutch springs and plates. Clutch inner basket, proper torque 65 / 70 lbft. Not even close. Finger tight plus a little. Maybe 5 lbft to remove the nut. Cush drive, same required torque of 65 / 70, it to was 5 lbft max. Both are supposed to have lock washers and loctite. Lockwasher yes, loctite no. Cleaned all threads and reassmbled to proper torque with loctite. Assembled and ran the bike. Initially clutch worked, then began dragging until the clutch went inop. Dis assembled. Found the cutch inner basket had a depression from the needle bearing inner race. This caused insufficient clearance between the inner and outer baskets when hot. Machined away the worn area. Reassembled again the cush drive and clutch to proper torques with fresh loctite. Again reassembled the clutch and saftied the springs. All back together, fires right up. This time the clutch releases predictably even when hot. So maybe, just maybe, since there are no fasteners between the center cases, this thing can run until it needs bearings or a top end and then we can replace the crank. Also, cush drive removal. We had purchased the cush drive puller from Alex Snoop. Without question, money well spent.

I do, some times. Trust me, I laughed after I Googled it. Yes, a very good chuckle.

Guessing Poofs is some other meaning for non USA English, I can only imagine what I have posted now to create such humor. OK I googled Poofs, yes, no doubt you all had good laugh over that one.

Good tips. This motor was coming apart for a full rebuild, so rust in bearings was no concern. For engines just seeing top end work, upside down to disassemble is good. This engine came out of a recently purchased used bike, no way to know the past history, but it was certainly rusted studs holding the cylinder on.

The bike had been running ok while the new carb was jetted. Prior to this, it was started and idled, with an easy pass up and down the road. The poof and failure to start was an obvious indicator of problems. While troubleshooting, never did I expect the flywheel to have come so loose and move the igniton timing so far off to cause the poofs. The blessing is ultimately that with the flywheel set well on the repaired taper, a replacement key installed, she fired up on two kicks and runs with snap and power. Hoping the makeshift repair to the taper should hold until the engine needs to be torn down for other concerns. At that time the crank and flywheel will be replaced with a rebuilt crank and undamaged flywheel.

Recently, there was a need to remove the cylinder from one of my friends 72 MAR 250s. With the head removed, we expected the cylinder to slide easily off the studs. P, time and water had corroded the studs and cylinder along the cylinders entire height. We soaked the 4 studs for a couple weeks hoping to have the cylinder release. When the cylinder refused to release and be removed, next I attempted to unwind the long studs. While i could see several of the studs twiting as I tried to remove them, each would untwist back to where they originally were positioned. Seeing this I feared the studs would break causing greater problems. Heat was even applied hoping the studs would release and unwind, still the studs and cylinder remained as one. Ultimately, being extremely careful not to damage the cylinder, I resorted to an air hammer on the ends of the studs. Yes this would ruin the studs but drastic measures were needed. With two people, one holding the cylinder and the other operating the air hammer, we spent about 30 minutes with the first 15 minutes just barely getting the cylinder to move away from the base gasket. Once we saw movement, we tried to unscrew the studs. One removed easily, while 3 refused. Continuing, the cylinder moved away further and allowed a second stud to be removed. The last two studs refused to be removed. With care the cylinder was raised until the studs sat just proud of flush. With the cylinder about 1 1/2" above the base gasket surface, the remaining two studs were cut while the cylinder liner was protected from damage by the saw. With the studs cut, the cylinder removed easily. The studs were able ro be removed with no cylinder damage, but did require a well supported cylinder and smart blows from a hammer and punch. With short stubs of the remaining studs, a small bit of heat was applied and the reaning cut studs removed easily. Some may not realize that by design, the 250 OSSA cylinder and head do not have a gasket sealing the studs to prevent water from filling the gap between the stud and cylinder. The water can collect and remain causing corrosion. When shoping for studs Alex Snoop advised using a high quality paint to minimze corrosion by painting the studs. This will be done during reassembly. Currently the entire motor is apart awaiting a crank rebuild, bearing and seals.

Yes, if you ask my friend about the OSSA he would agree it was a shed of a restoration. Regardless he realized the bike had been misrepresented by the previous owner. Now many months and dollars into it, he should get to start riding and enjoying it. Hopefully. Other than splitting the cases, and we are prepared to do that, he has transformed so much that was cobby workmanship into a very nice rider MAR. I did happen upon a second MAR he was able to get reasonably priced. So even though he will be losing a small bit of money in the end, his collection should have a nice fun rider MAR and a well done display MAR that will be very close if not as it came new in 72. Other than a few quirky things, thes old OSSA machines are pretty basic. Not perfect by comparing to a modern machine but still very simple.

Shed of a restoration, not sure of the meaning. I do have a few photos, need to find them, maybe on the phone.

Actually, no, he had no rides on the bike. As for the jet change, the previous owner installed the wrong carb so an OKO was installed. It became pretty obvious, the previous did not smooth anything, in fact his file marks to the key way are obvious and still did not allow the key to seat in the keyway. Basically, the flywheel never seated on the taper. It was also odd to see serious leakage along the center case gasket above the gearbox. A quick check of the case screws made it apparent they were never fully tightened. Best assumption, the flywheel tapers never matched and the flywheel was not torqued to specs.

Not my OSSA MAr, but my friends. The bike he bought a while back, advertised as restored needing nothing has been one hack after another. To late to complain to the guy, and the seller was not honest in how he described and displayed the motorcycle. It was a long distance sale, so between emails, phone calls and videos, the bike was bought and shipped. Suffice to say the seller, that did the work should not handle tools and has no real regard for quality. Along with many issues, the most recent occurred last week. While getting the jetting dialed in, the engine lost power and began rattling. My first comment when told about this on the phone was he seized it. My friend said no, he knew seized and it was not that. He brought the OSSA to my house last week. It had not seized. Fired it up, and lightly rode once around the house. Agreed it was lame in power, but not sure why. I did grab a handful of throttle while in neutral. She wound up then began gurgling and died. A new spark plug and it ran for a moment but died. Would not restart. Checked fuel, ensured carb jet had not fallen out. Disconnected kill switch entirely. Checked for spark, tough to see but there. Nothing appeared wrong. My first thought was the resistor spark plug cap had failed. Not sure why it had one, but swapped on another plug cap. No change. Since my OSSA is apart waiting on parts, we installed my coil. Still the same. Just to verify, we even installed my known good carb. No change. The truly odd thing was it acted like it had seized. While trying to fire it, there was odd poofs out the exhaust, and even poofs out the carb. It got late, I told my friend, unwrap the cobby black electrical tape job the seller did to the wire harness. See if there is a short. Other than that pull the flywheel and install the stator from his other MAR that we have the engine torn down, making it an easy swap. Since the skidplate needs to off to remove the side cover I awoke the next morning, called him, said do not unwrap the wires, pull the flywheel. I suggested the key had sheared. He removed the ignition side cover, then pulled the flywheel. What a mess. The previus owner had issues where the flywheel had come loose. Obvious attempted file repair. Divits in the crank taper and flywheel taper from the previous key either shearing or was knocked out on install. The issue we dealt with was all sections of key were there but sheared. I took a road trip to his house, brought some tools. With care and a steady hand, I blended out the raised points on both tapers. We then lapped the tapers for a good fit. While still damaged, and we know it, evything was cleaned and assembled. The flywheel nut was installed with Loctite and torqued. She fired up in two kicks and ran well. The guy that owns it is finding a crank, flywheel and other bits. For now it is a good temporary repair that will last until we need to open the motor. I did mention, if the guy that built the motor and bike was this much of a hack, we should remove the clutch cover and verify the cush drive and clutch are secure also. What a week. We expect it will easily last the summer, then it can be torn down. So if buying a bike, never be surprised, good or bad. If your MAR gets wonky on how it runs, consider the flywheel. I do give credit to a post I read here a while back where an OSSA did not run correctly, turned out his was flywheel also.

Like the idea of larger footpegs. Does anyone have photos of the KX footpegs installed on a MAR, or know the details of how to modify them?

I have never rebuilt an MAR, but do have one of my friends I will be going through very soon. I did notice they bearings are supposed to be a C3 category for tolerance. Consider that when purchasing bearings. If I can find where I read that I will copy and post it. That spec may only be for the crankshaft main bearings.

The work continues. I had no major issues to get the MAR running and have ridden it around the yard. Most if not all of the parts needed are now in hand. The frame is currently being blasted and epoxy primed. In an effort to save some cost, I will paint, rather than powdercoat the frame, swingarm and kickstand. One expense not anticipated was the spokes having aluminum nipples that would not release even after soaking in Kroil penetrating oil. Needing new spokes front and rear had me also replace the hugely flat spotted front rim also. The front rim had also been welded long ago and showed a lot of cracks. Wheels are rebuilt, need to be tensioned and trued. Forks have been rebuilt, totally disassembled, then built up with new seals and dust seals. Silencer / Spark Arrester has been straightened, blasted and repainted. Then reassembled with new packing material and USFS approval highlighted for easy reading. The new replacement parts have been test fitted and are ready to install as the bike builds up. Fuel tank, seat, cables, throttle assembly, tires, tubes, rimlocks and more. Much of the recent effort is removing corrosion and refinishing various parts. Again, not restoring it, making it into a resto mod rider. Keeping the overall look of the original machine while overcoming things like the fiberglass tank and alloy fenders. I think it will be a worthwhile project once completed.

Woody, the OSSA is coming along. Regarding the exhaust center section, I am going to repack it. I have a section of stainless automotive exhaust tubing that matches the OSSA center pipe diameter. Planning to make an access cover that is removable, allowing repacking without any welding required. This will also allow repacking over time if needed and will be an easier task. In regards to the oem OSSA packing material, do you know if it was a stainless steel wool or fibreglass material? I have access to both. Thanks

Excellent humor. I agree the parts will wind up matt finished in time. The Spanish aluminum needed some love to remove light corrosion, and you are correct about the doloop of muck helping the finish from polished to patina. The aluminum mudguards do rank in the same catagory as polishing the skidplate. Not too worried about polishing the skidplates outer surface, just need to polish the inner surface to allow easier cleanup from the leaking oil out of the dumb right side shift shaft stub.

Not restoring. Building a resto mod rider. Trying to keep the 73 theme though. In regards to the aluminum parts, I am not 100% certain on what parts get polished. The fenders /mudguards are plastic, so those will not be polished. Currently I have polished the front and rear rims, front and rear hub ignition side cover, lower fork legs. Next will be the brake backing plates, and clutch cover. These items I am not sure about if they need polishing or a brushed type finish. Triple Clamps? Clutch and front brake levers? Lever perches? Sheet metal aluminum chain mud guard? Skidplate? Rear Sprocket? Anything I forgot?

That sounds how mine is. Clip, washer, spring washer.

Thanks for the lead. Google search worked well. Searched Fantics. Appears this machine is modified with the front forks and wheel, plus the rear wheel off a drum brake Fantic. There are other mods, but that pins down the wheels.

I was sent this photo, pretty certain we know the guy in the photo. What I am curious about is what hubs / brakes are those. The forks do not look stock either. Compared to stock brakes, those seem much larger diameter.

I suspected humor, and accepted it as that. However, I am sure someone here somewhere has done exactly what you posted. Over thars at slow speed. Agree that super powerful brakes may not be vintagey, if that is a word. But seeing the efforts some have taken appears to be a problem needing something. Case in point, this 73 OSSA MAR I have...the rear brake is small with kind of narrow shoes. Add to it the craziest cable setup ever designed. No doubt good enough for some stuff, but as mentioned in another post, it may require steel soles followed by a sparking light show. I suppose modern brakes on both moto and mountain bike are pretty evolved. Seems I am comparing an older drum brake passenger car to modern sport sub compact. New is smaller, lighter and better brakes. But we did survive the older drum brakes and talk about it.

I tend to disagree with the over the bars concept, while possible, that would seem more technique or a brake system with no feel or progression. My asking about brakes being too powerful, is, as I see modern riders hopping about, wedged between rocks, those brakes must be very powerful. For the drum brake vintage machine, is this simply not needed, or is it too powerful of a brake system. As I mentioned, this is new to me. I read mixed comments. What is the truth in all of it?