Showroom quality 1973 CR250M

I had a heck of a time finding a complete used bike to restore, but as of now, I have actually found over 60% of a complete 1973 CR250M motorcycle in perfect NOS parts still in their Honda paper and plastic packaging. I just acquired some true UNICORN parts that I never expected to be out there. These 1973 parts are almost a half century old, still in their original shipping boxes along with the packing inside and never taken out of the original boxes. Can you guess from the part numbers what 1973 Elsinore parts these are? These are the 2 most desired and very difficult to find major parts even as badly beaten used parts...





On Monday, I will be removing them from their original boxes for the first time since Honda boxed them up at the factory and will share the pics.

It wasn't easy.. took almost a month of negotiation.. wasn't over money, he wasn't comfortable doing business with someone he never did business with before. They were painfully expensive, too. Not sure if there are even any other 1973 CR250M NOS tanks and pipes on the planet. Will share pics of the contents soon. Opening the boxes and removing the packaging will be like opening King Tut's tomb for the first time.

Some major NOS parts see the light of day for the first time in decades..

These early aluminum tanks were so beautiful.







The steel in these old down-pipes are much thicker than a modern pipe, but hard to believe they were expected to last more than a few laps around the track.

Hi Damien,

I thought I was done as I have no more room for bikes, but here we go again. This bike is going into my bedroom. The bike is so small (compared to a modern mx bike), I can put the bike at the foot of my bed and still see over it and watch TV . However, like most of my builds, I always get carried away. These NOS parts are crazy expensive and I am amazed how much of it got hoarded away over the years as people's retirement investments.

I actually found them on a Japanese website. Took almost a month of negotiating before he was comfortable selling to me as he was hesitant to do business with anyone he hasn't sold to before.

Mike; Not quite as exciting as your cool modern factory parts, but the bike is a piece of motocross history that is also quite a piece of eye candy. I see quite a few restored bikes out there, but the paint colors are off a shade and things here and there that aren't right. The only thing I have to repaint is the frame and engine center cases, for the most part. This NOS parts I am using will all have the original paint. My clutch cover and ignition cover are a kind of "dirty black" as I remember they were.. black with a slight brownish tinge. The bike will run like new, too with all NOS internals.

You have a 1973, too, Paul? Let me know if you need any parts, when you do your build. As usual, I got out of control with the new parts. I am replacing many things that would have been perfectly fine with a fresh coat of paint, but I out out the cash just to have as much of the original paint finishes as possible. Engine just had the crank replaced fairly recently with a new OEM crank, but I am replacing it again with an NOS billet crank. All the engine internals will be new NOS save for a couple of the transmission gears.

That's beautiful Paul.. really the only remaining part I would still like to put on the Red Rocket. How long was the wait in total from ordering?

Will you paint it Tahitian red or leave it natural?

That bike is absolutely beautiful Paul.. I would have made mine close to that if my bike wasn't such an original barn find. Did you get that fuel tank from Holley? Love that swingarm.. 10-12 weeks isn't bad. I may have to spring for it because I am not in love with the oem swingarm which flexed and bent on mine so much when I raced this bike as a 135-140lb kid back in 1979. Too many bad memories of the oem swing arm and shocks.

Where did you get that pipe? I noticed that it curves down lower just below the frame like the RC pipe did.

Is that a VMX or 76-77 CR125 OEM front fender?

You just need to find that white gas cap like the RC's had.

mike

Many hundreds of NOS parts are piling up in my home office such that I needed to organize and label the parts to keep track of what I had. I had already labelled and bagged all the parts from the complete 1973 CR250M I had disassembled so I am swimming in parts at this point. I have built a lot of motorcycles in the past, but never have I tried to build a motorcycle from mostly all NOS parts because I didn't think possible for an old bike. I was wrong.. there are a lot of people put there hoarding the 73/74 CR250M parts knowing it would be an iconic bike for builders in the future. When I was building my 1979 Red Rocket, there were not as near as many NOS parts available.

It only requires money and a little detective work to find these parts. Nevertheless, an NOS front number plate can cost about $800 and an NOS fuel tank several thousand dollars. Used parts aren't much cheaper. A cracked and scraped side panel can still cost $350. Not a build for the faint of heart, a badly rusted air filter cage on ebay can go for $250, a many times crushed and repaired exhaust pipe can go for $1,000. The other day a guy on ebay was selling half of a front plate for $200.. almost half the plate was missing! They even go as far as selling used head gaskets and clutch plates for not small money, so with all this craziness going on, the spendy NOS 73/74 NOS parts seem like a better deal.

Here is an NOS rear fender for which I mounted to the frame temporarily to affix the sticker that outlines some of the specs of the bike. I still need to get the frame bead blasted and painted, but I prefer assembling new parts as they come in so that gets the priority


This build will include NOS parts that are not just the pretty cosmetic parts, but all the engine internals (save for a few gears) will be NOS. This bike will not just look showroom new, but it will ride and feel new. I have a separate bag of small NOS parts for the carb, clutch, fork, shocks, ignition, body hardware, etc. In addition, I have boxes with an NOS billet crank, stator, both clutch baskets and pressure plate, transmission and shift shafts, etc.


Every part in this assembly is NOS. I noted that while Honda used gloss black for the frame, the brake plates, hubs, brake arm, silencer stay, chain guide are all painted Satin Black which should be useful info for those people looking to repaint their restoration parts. The NOS engine covers are what I would call a "dirty" semi-flat black. There is a hint of brown in this black, like the color of dirty motor oil. I found myself replacing a lot of really nice used parts that just needed a fresh repaint, just to get the original, unmarked finish of the NOS parts.



Again, the hub, brake plate, brake arm, hardware are all correct NOS. Naturally, NOS cables, axles, etc. will be used.

Here are most of the NOS 1973 CR250M parts collected for the build that I arranged spatially to keep tabs on what I have so far. I have already started assembling things like the brake plates, triple clamps, handlebars and controls. In the bags are all the correct NOS hardware and small parts for building new shocks, forks, all engine/ transmission internals, ignition, etc. Every control, cable, lever, pedal, axle, etc. will be new NOS. I have a few more NOS parts that I couldn’t fit in the picture as well as a complete disassembled bike in the other room. None of the parts in the pics are restored, but are new OEM taken fresh from their Honda packaging, which was often paper from that period, the way you used to get meat from the butcher .

There are a few NOS parts I am still looking for;
-lower left fork leg,
-one more rear shock spring (main spring),
-rear brake pedal pivot bolt,
-one rear shock seal cap

This build aims to be the next best thing to finding an almost half century old bike still new in the crate.




I still need to get my frame and swing arm bead blasted and painted. One of the exhaust pipe spring mounts was mussing so I fabricated a couple from tool steel rod. Came out nearly identical. I need to get it TIG welded to the frame before painting. Otherwise the frame is perfect with no rust or dents in the bottom frame rails. It is one of the few parts I am reusing from the original bike since since other than the seat, engine center cases, cylinder and a couple of other minor pieces, all will be replaced by NOS parts.

Here are the part numbers for the remaining NOS parts I am looking for in case anyone may know of someone with these parts;

-Shock body/ seal cap for a 10mm shaft (52412-357-010)
-Standard shock spring (52402-357-670)
-Lower left fork leg (51521-357-300)
-Rear brake pedal pivot bolt (46513-357-010)

I haven’t posted in a while since a lot of what I was doing; sourcing parts, cleaning, painting, etc. are not real exciting things to write about. I also ran into one problem after another with things like defective NOS parts and other very unexpected problems that needed figuring out, however, I am finally at the fun stage.. the final assembly.. and will post quite a bit as the bike comes together including an explanation of the problems I ran into, how I solved them and other things that will be useful to anyone else looking to restore what is now.. and hard to believe for an old guy like me that used to ride them when they were still available at the local dealerships.. a half century old antique! There was a lot of relearning, rediscovering and even new learning for me. Compared to today’s standards, these bikes were rather crude and manufacturing quality was not that great, to be honest. They are still a beautiful piece of moto history, though,


Getting started, the frame was sand blasted after putting cheap hardware store metric bolts in every bolt hole as well as plastic plugs in every orifice. This helped keep the bolt threads unmolested and sand out of the orifices that could fall out during the painting process. Before doing this, I used a thread chaser in every bolt hole, fixed the exhaust pipe mount with a time-sert threaded insert (this is one area on the bike that is very weak and often in need of attention. I did also have to weld on a new wire loop on the lower frame for an exhaust spring, but other than this, the frame rails were perfect with no dents or rust. The welding done by Honda at the factory was atrocious.. unsightly and I can’t believe I actually used to take these bikes over jumps when I was young.. the OEM welds looked like they were done by a 1st grader. Also, be careful when removing the lower steering bearing race. It is a bitch to get out… it sits in a deep recess that is a tolerance fit the whole length of the recess and the race will try to cock sideways on you in spite of careful efforts as you bang it out. It was a real PIA. Also, I had a major problem with the bronze swingarm bushings that someone had installed previously.. they were impossible to bang out and blind bearing pullers were too short.. I had to use a Dremel tool with a grinder bit to cut 2 lines down the length of each bearing to get them to collapse slightly on themselves and relieve the pressure from the press fit before they would bang out with a long chisel. It was a lot of work.




The frame was painted with a PPG 2-stage gloss black at the local paint shop. The other parts were painted at home to replicate what Honda did at the factory.. only the frame had a decent paint job and the other parts such as the inner engine cases, exhaust stay, foot pegs, kickstand, etc. did not have a high quality paint job from the factory like the frame. Anyway, few of my parts needed painting because I was using NOS parts in pristine condition.

Here is an example of an NOS part that is very hard to find.. it is a chain rub block that mounts on the inner frame. I always thought they were rubber, but actually it is a piece of hollow metal that Honda decided on in all their infinite wisdom and lack of technology at the time.


The rear shocks were rebuilt with all new parts and only the shock bodies were salvaged used parts. Finding the right color silver to exactly match the oem grayish silver was not easy and I tried 10 different rattle can paints before I was satisfied with Krylon “Dull Aluminum”. This was the closest I could find. I used 5 weight oil and heavier weight oil was not recommended by Race Tech. Dampening is minimal in these old designs and I would recommend using 5 or 7 weight oil. I used a total of about 115cc of oil in each shock. You want to fill each shock to about the level of the bottom of the cap threads and so each rod guide is just covered by the oil. You do not want to overfill it so that you start to compress the oil when you screw the cap down into the shock body. As for the shock springs, I refused to reuse 50 year old sagging springs and sourcing NOS springs was not easy. The lower springs were somewhat easy to find, but for the upper main spring I was only able to find one 250 spring while I found a pair of 125 springs. Honda only offered an optional softer spring for the 250 which you don’t want as the standard springs were way too soft. What I discovered was that their thinking changed after their first Elsinore launch and the 1974/ 1975 CR125 standard spring was in fact not a lighter spring than the 250. I measured the wire thickness which was the exact same and did compression tests and they seem to be the exact same spring rate. Moreover, the 125 spring is about 1/8” longer than the 250 spring so they offer a little more preload. I went with the 125 springs as the better option to match the heavier race tech fork springs I am using on the front. I found the best way to remove and install the shock springs was by tying them to a floor jack with two thin nylon tie-down straps and then jacking up the jack. Worked like a charm and protects the paint on the springs compared to other methods. The blue shock decals are available as reproductions from Re-MX, but you will only find the “360” and “395” model decals and not the correct “357” number decal. Still makes for a good visual effect though even if the number is not correct. I also recommend getting the special shock cap wrenches from UTI. There are different wrench patterns for the caps for the 10mm and 12.5mm shock shafts. They also sell very nice CNC machined Delrin shock spring rub sleeves that look identical to the originals but are much stronger and self-lubricating.




I discovered that the NOS shock spring preload adjusters didn’t match even though they had the same part number. It turns out that the first design was breaking all too regularly so Honda switched to a stronger design in late 1973 and 1974. After a quick trade with another builder, I ended up with a matching NOS pair of the later style. In the pic below, you can see the 2 different preload adjuster designs and how the older design was very weak at its thinnest point. Not a lot of metal there.

Likewise, the carb was rebuilt using all NOS parts and I only reused the carb body and fuel bowl which I sent out to be vapor blasted. Be aware that Honda used 2 different carbs in 1973-1974.. I have the older "679B" design. Here is a pic (below) of some NOS carb floats which were really hard to find, but got lucky. I also replaced the carb cap, slide, air screw, idle screw, choke mechanism, needles and jets with correct NOS parts so I had close to a brand new carb at the end. I wanted a bike that not only looks dealership fresh but also runs like one.

One of the things I had to figure out was how to get grease into the old-fashioned grease fitting since it needed to stay NOS and original and replacing with a modern fitting. This is what is called a "ball-type" grease fitting and an adapter for the grease gun is not easy to find, but I found it at SAE products. Cost me ~$85 with shipping to put grease into that swing arm fitting. Alternatively, you could grease the swingarm spindle really well before assembly, but you wouldn't pack as much grease in there. The rear brake pedal has the same ball-type grease fitting so I will use this grease gun adapter again for that.



I have had a lot of problems with the Honda NOS parts, taken right out of the original unopened packaging, not fitting. The NOS rear fender had rivets that were far too long to mount on the frame so I had to cut them back a bit. This is the case of missing the last finishing step at the factory. All was well after a little Dremel tool action as I just had to cut off the excess hollow shell of the rivet and never touched the stud that runs down the middle of the rivet. I just had the same problem with NOS shift forks which were never finished honed to fit on the shaft. I had 2 sets bought from different sources that had this problem. I am talking about the stronger "395" shift forks. Honda quality was a bit spotty in those days, perhaps.




Here is another shot of the NOS chain rub pad.. usually missing on most used bikes such that they are almost a unicorn part now and rarely seen. They are just held on by tiny screws so no wonder.. and once the chain cuts through the metal, the chain will grab that part and rip it right off the frame. No exactly a genius design.


One thing I didn't mention about the swing arm was that I had decided not to use the original nylon swingarm bushings even though I found an NOS set. I first bought bronze bushings but the ID was not machined properly and the internal swingarm collar would not fit through it. I then sourced another set of bronze bushings from a different manufacturer which fit fine. I also bought a set of Delrin bushings which were very nice and fit perfectly, but decided to go with the bronze in the end. This presented the next problem.. I had a set of extremely hard to find original "357" swingarm dust caps. No matter how hard I tried, I could not get them to fit over the ends of the bronze bushings. However, the Honda OEM supersession "52144-356-005" part fit just fine although it is not painted black like the original "357" dust caps. Instead it is zinc coated followed by a rubberized coating. Once installed, it is extremely hard to notice the difference. I guess the original design were rusting out and Honda made the change. Another unexpected problem solved.

Another thing I noticed is the NOS fenders and side plates are not really painted on the inside/ underneath. They maybe have a very light silver dusting at most or nothing at all or perhaps some green overspray. Moreover, while the rear fender is finished in a high gloss clear over the special metallic silver, the front fender has almost a matte finish. The green on the tank and number plates is also very flat.. they never cleared over the green stripe on the tank, but instead painted the flat green stripe over the cleared aluminum tanks supposedly to minimize glare from the sun in racing conditions . I heard the brushed finish on the tanks was created using burlap, then cleared, then the stripes painted. The black border stripes on top of the tank are 0.333" wide and separated from the green stripe by 0.25", fyi. Again the green stripe is very flat, while the border stripes are gloss black.

Was hoping to get the engine done today, but then realized I didn't have a crank puller/ installer, so I mocked up the tank and started building the front wheel. All the parts in the pics below are Honda NOS except for the frame, shock bodies, fork stanchions and one of the fork damping rods. For the forks, I used 170cc of 20 weight oil in each fork leg (manual calls for 165cc for a dry fork). While the heavier weight oil is recommended for the fork, it is not recommended for the shock (per Matt at Race Tech). I also installed a heavier rate single spring rather than reuse the marsh mellow soft dual progressive springs that Honda originally equipped these bikes with. Anyway, I could only find the smaller springs as NOS parts and I wasn't going to use half century old main springs. I am running just 5mm of spring preload which I adjusted with spacers on top of the spring.

The lower fork legs came from the factory with a clear coating. Hard to tell, but they may have had a gray coating under the clear. While a am aiming to be very close to original with every minutia with this bike, I pondered whether to go with the original coating or to polish the legs. For the last 3 months I had both side by side in my office before I decided a polished lower leg looks so much nicer by a mile. This is the one area I deviated from the original and I wouldn't consider it with any other parts, but it looks right to me.