pmk Posted November 6, 2016 Report Share Posted November 6, 2016 I first will say I appreciate the experience and knowledge here. I grew up riding when these machines were being made, but never considered them as I was a kid growing up racing MX when the Japanese bikes arrived and became dominant. Fast forward to 2016, I wanted a trials bike. Many reasons why. My good friend and riding buddy purchased a 72 MAR about a year ago that was supposedly very nice. He learned it was good but lacking in the fine details and he does not have or own junk. A few weeks ago, knowing he needed some original parts, I noticed another MAR on a Facebook group that was for sale reasonably inexpensive. He acquired it. So he had plans to build a very original machine with original parts, and a second rider. His words were that of we could ride together. During the time while his second bike was in transit, the wife and I travelled for both family stuff and vacation. The wife and I ride tandem bicycles, both on road and tandem mountain bike. During an event, I spent time with a friend and his wife. With a combined age of my friends at 160 years, it is always fun to see them and ride with them. They still to this day ride a tandem mountain bike off road. During one of the meal gathering, I was talking with my tandem mtb riding friend, and long time dirt bike rider, about trials bikes. He knew I wanted one, and we discussed my local friends two MARs. He informed me he had one that he had purchased new in 1972. He had ridden it a bunch, but his wife also told me it was her favorite dirt bike of all those she rode. The following morning, they insisted I pick up the MAR and if possible bring new life into it, or if beyond reasonable effort and expense to get going, use parts as needed to build one of the other two into a more original machine. So we drove to their home on our return trip to Florida, and picked up the MAR. It had been sitting for a while, stored outside, but had been run randomly but not in a while. The owner said the last time he rode it the clutch was stuck and would not release. She is rough cosmetically, but viable still at the moment. Ironically the engine is free and smooth. 1 Quote Link to comment Share on other sites More sharing options...
lotus54 Posted November 6, 2016 Report Share Posted November 6, 2016 (edited) As an original machine, I hope you can bring it back to life rather than part it. Everything is avaliable and are great vintage bike. I ride my 74 Explorer from time to time- it is very good, except the brakes! (I bought my Explorer from the original owner also) Edited November 6, 2016 by lotus54 2 Quote Link to comment Share on other sites More sharing options...
pmk Posted November 6, 2016 Author Report Share Posted November 6, 2016 Yes, it does have matching numbers and I agree parts are available. The possible wrench in the works is how much it will cost to make good vs what it is worth. I am not really into making it a perfect restoration, rather a nice rider that retains the look and ambiance of a vintage trials bike, I think... Quote Link to comment Share on other sites More sharing options...
lotus54 Posted November 7, 2016 Report Share Posted November 7, 2016 It looks very complete. I ditched the Amal and put on an OKO from Mid-Atlantic Trials. Cheap and works wonderfully (kept the Amal in a box). If the engine/trans is good, then bearings, cables and perhaps sealing the fuel tank and could be a great runner. Mark http://www.mid-atlantictrials.com/OSSA.html Quote Link to comment Share on other sites More sharing options...
pmk Posted November 7, 2016 Author Report Share Posted November 7, 2016 Mine has the single needle IZD carb. Original owner mentioned it ran well with it for many years. Quote Link to comment Share on other sites More sharing options...
bondy Posted November 7, 2016 Report Share Posted November 7, 2016 (edited) you will have it looking like mine. Edited November 7, 2016 by bondy 1 Quote Link to comment Share on other sites More sharing options...
pmk Posted November 9, 2016 Author Report Share Posted November 9, 2016 Spent some time today doing the common clean the carb, lube cables and assemble it enough to see if it runs. After a bit of verifing spark, ensuring fuel she would give that poof like it wanted to run. Accidentally, I overlooked a paper towel in the head pipe, and that poof just sound like a plugged exhaust, some since the slincer had not been cleaned or verified clear, I pulled it thinking it was plugged up. So my care while washing and that paper towel had moved into the mid pipe stinger. Next kick it blew the paper towel out and fired up. Ran it several times on the stand. Engine sounded good with no bad sounds. Next, I will give it a couple easy runs to ensure the gearbox feels good under a load. After that, it comes appart for some cosmetic refinishing, and I plan to split the cases, replacing seals and bearings, with hopefully no issues on internal stuff. So at this point, it looks like she will be a nice machine, not restored but for riding while keeping the vintage theme. 1 Quote Link to comment Share on other sites More sharing options...
pmk Posted December 13, 2016 Author Report Share Posted December 13, 2016 (edited) Still moving forward. Guess I am doing a restomod as they call it with cars. Got a Clarke plastic tank in white. Broke the budget and ordered a Smartcarb. Got a box today with vintage shocks, probably going to install Curnutts. The rest will hopefully be ordered soon and seems available. Any thoughts on the Curnutt shocks? I also got a pair of very early Works Performance shocks, those would need softer springs and not so sure the finned bodies would fit well. Need to add, some of the items off my bike are headed towards my friends MAR he is making original. IZD single needle carb, 4 shocks hoping to make two originals, original headlight and wire harness, etc. Edited December 13, 2016 by pmk Quote Link to comment Share on other sites More sharing options...
lotus54 Posted December 13, 2016 Report Share Posted December 13, 2016 I had Curnutts on two of my old OSSAs (stiletto and GPII Phantom) For a MX/desert bike they are great. I'm not sure how well they would work for trials. Quote Link to comment Share on other sites More sharing options...
pmk Posted December 13, 2016 Author Report Share Posted December 13, 2016 I had Curnutts on two of my old OSSAs (stiletto and GPII Phantom) For a MX/desert bike they are great. I'm not sure how well they would work for trials. The budget on cost was perfect, so no loss in trying the Curnutts. No doubt, The spring rates may be a big factor unless the oem Betor springs could be salvaged and made to work. As for Curnutt damping, I have rebuilt many shocks but these will be my first Curnutts. I also got a set of probably first generation Works Performance shocks. Those would need springs in order to work and the cooling fins will probably be a concern unless I cut a good portion of them off. Time will tell how it comes together. Quote Link to comment Share on other sites More sharing options...
feetupfun Posted December 13, 2016 Report Share Posted December 13, 2016 See if you can nobble the damping on the Curnutts or the Works Performance shocks while you have them apart. Standard they have way too much damping in both directions for trials use. For your friend getting the four original type Betors, there is a bloke in the USA selling shaft seals for them and you can also get the mounting rubbers. I sometimes run them on my OSSA. they are not quite as good as modern Falcons for damping action, but I love the look of them Quote Link to comment Share on other sites More sharing options...
pmk Posted December 13, 2016 Author Report Share Posted December 13, 2016 Do you happen to know who has seals? The one pair of my MAR have badly pitted shafts, but good everything else. The pair my friend has were hammered and the pot metal sealheads are shattered. His shafts are not perfect, but should polish up ok I hope since that will be a display bike. My friends second MAR will be his rider. Like mine it will not have stock rear shocks or a stock carb. Ultimately, we should have two fun MAR riders. Quote Link to comment Share on other sites More sharing options...
pmk Posted December 13, 2016 Author Report Share Posted December 13, 2016 As for the Curnutts being overdamped, the recommended oil was Type A transmission fluid. Seems Curnutt even recommended a mixture of Type A tranmission fluid and Diesel fuel. With so many fluids and weights available today, and the pretty basic design, I think they will respond well to different viscosities. The metering rods appear to engage well into the shock stroke, basically the great grandfather of the KTM White Power No linkage PDS. Regardless it will be fun. Quote Link to comment Share on other sites More sharing options...
lotus54 Posted December 13, 2016 Report Share Posted December 13, 2016 I have an article on the Curnutts from about 1970. They used a floating mid valve, I don't think anyone else did. Seals are standard avalaible stuff, and they can still be sent in for rebuild. I talked to the guy that used to work with Charles (related also?) and he can even make them up. I am missing one form my GPII. (Long story, but I have it back) and need another. At a standstill they felt like they didn't have any rebound damping, but they worked wonderfully out riding. Way better than the Betors. Quote Link to comment Share on other sites More sharing options...
feetupfun Posted December 14, 2016 Report Share Posted December 14, 2016 Do you happen to know who has seals? The one pair of my MAR have badly pitted shafts, but good everything else. The pair my friend has were hammered and the pot metal sealheads are shattered. His shafts are not perfect, but should polish up ok I hope since that will be a display bike. My friends second MAR will be his rider. Like mine it will not have stock rear shocks or a stock carb. Ultimately, we should have two fun MAR riders. http://www.ebay.com.au/itm/Betor-Rear-shock-seals-Bultaco-OSSA-Made-in-USA-/252149753514?hash=item3ab54be6aa:g:FlwAAOSwhcJWNDK5 1 Quote Link to comment Share on other sites More sharing options...
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