Turning a 1979 CR250 "barn find" into a 1978 RC250 replica

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7/24/2018 8:04 AM
Edited Date/Time: 12/24/2018 2:36 PM

I wasn't looking to start a new bike project right now, having not quite finished a 2001 Japan RC250M project, but came across a really pristine, all original 1979 CR250 near me that was hard to pass up especially since this is a very nostalgic bike for me. It is a bike I raced as a kid and one that I was really fond of.. killer engine.

Here are some pics of the bike the day after I picked it up and not yet washed. I have totally disassembled the bike, and best I can guess is that this bike was gently trail ridden for maybe 20 or 30 hours. The only wrench this bike ever saw was the rear axle nut to adjust the chain. It was pretty clear that the wheels had never been removed from the bike and the original "Claw" tires still had most of their tread left. The grips and levers looked almost the day they left the dealership. Obvious that this bike not only had not been raced, but it doesn't even look like the bike had ever been even in a small crash. The paint on the fuel tank was unmarred and no sign of even the slightest knee scuff marks. The same goes for both unmarred engine covers. The seat still looked brand new.. no cuts or scratches. Most bolts still looked quite new and the trans oils looked pretty good after sitting in a dry place for probably close to 40 years. There was a little bit of fading on the front fender, but other than that, the plastic all looked good. There was no dry rot on any of the rubber parts either which were still supple like new. There were remnants of a mouse nest in the airbox, but this bike is pretty much a time capsule from the past. The few minor scratches on the swing arm and left side plate looked more from having things piled up against it in a garage than riding. This bike is 100% original.. no parts broken or missing, so the conundrum for me is how much to preserve in the rebuild and how much to repaint and replace with cool new parts.






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7/24/2018 8:45 AM
Edited Date/Time: 7/24/2018 9:06 AM

The bike may be ridden at 1 or 2 VMX races, but will be primarily a display bike. I could paint the whole frame and motor to make it 100% perfect, but it would be a shame to paint over the original paint still in such perfect condition even if there are a few minor chips here and there. The aftermarket Tahitian red paint does not exactly match the original hue and I have bought 4 different brands so far. I will probably just clean and polish the fuel tank, frame and engine cases and only paint the rear swing arm, front chain guard, and cylinder/ cylinder head. Would you agree?

I would like to make some changes to make it look like a 1977-1978 RC250, but not modify any parts so that it can be changed back to showroom condition, if desired in the future. All original parts will be stored away for safekeeping and repainting kept to a minimum. The look I am going for is the RC250's and RC500's that Team Honda raced around 1978...






These were the days of true works bikes and even parts that looked OEM were not. Castings and material were different for almost every part. Moreover, the bikes the factory raced was a glimpse of what the bike sold to the general public would look like 2 years in the future, and each generation factory bike looked like a space ship compared to what the general public was riding at the time. Unlike my last build, this bike will not be using genuine HRC parts, but I have some cool HRC replica parts for it. The RC bikes of the time made such an impression on me.. I still recall the things that stood out for me over 40 years later. Here is what I think the bike will need to look like
an RC..
- White gas cap -- The OEMs had black gas caps, but the factory RCs had white. I just picked up a white cap from Japan
-Fuel tank -- the RCs had a different shaped tank that reminded me of the shape of a hump backed whale. I know where to get a replica tank, but I want to show off the original pristine tank so will deviate from the RC there
-Billet aluminum engine mounts -- billet parts were super trick in those days and I have already procurred the replica mount plates.. all three sets of them
-Billet rear brake arm - got one
-Red painted air box - I have thought about this carefully.. it would be a shame to paint over the pristine original part, so I am going to try using the red Plasti-Dip rubberized paint that while very durable, can easily be peeled off to return to the unmarred original surface
-Cool trick HRC hardware - I have the Dentons making the HRC replica hardware for me now
-Holes drilled in the drum brake actuating arms - will make this mod
-Aluminum swing arm with weld up the side - Not sure what I will do here yet. Not any replica arms available. This is TBD
-Black painted carburetor - The RC carbs were sand cast magnesium painted black - I am plaining to use a special gas resistant "2K" paint for my replica
-Fox Air Shox - Just got a nice set and is what I also used when I raced the same bike back in 1979
-White number plate background - got a nice set from a UK graphics supplier

There were some other changes that were not consistent through the season. For a while there, the factory team was using a 1976 style CR front fender. I may or may not make the same changes. Also, sometimes they ran black fork boots, sometimes blue boots and sometimes no fork boots. I may go without any fork boots.

Can you think of anything I missed that you think would be a must have in a 1978 RC replica build?

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7/24/2018 4:39 PM

What year did the Debruzer bar pad come into play ?

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There's something happening here, what it is ain't exactly clear.

7/24/2018 5:30 PM

ledger wrote:

What year did the Debruzer bar pad come into play ?

It was very late 1970's wasn't it? I see some sort of bar pad on Lackey's bike above, but not a DB pad. That could be an addition to the build.. they are still available. I am going to keep the original OEM handlebars on this build.. they are straight as an arrow. That makes it a rare and interesting item right there.

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7/25/2018 2:00 AM
Edited Date/Time: 7/25/2018 2:02 AM

unrestored originals in very good condition are imo the ones to have.,..anybody with a lots of cash can turn a bucket of shit into a good bike...

it takes dedication and luck to find the others..

my best eg: season and a bit riden 79 mk10 250 bultaco persang, seized and parked for 25 yrs, still had his race numbers on it, 99% og....$650..

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7/25/2018 6:39 AM

make1go wrote:

unrestored originals in very good condition are imo the ones to have.,..anybody with a lots of cash can turn a bucket of shit into a good bike...

it takes dedication and luck to find the others..

my best eg: season and a bit riden 79 mk10 250 bultaco persang, seized and parked for 25 yrs, still had his race numbers on it, 99% og....$650..

I would agree with you, but also consider that it takes a lot of cash and lots of hard work to turn a bucket of bolts into a gem. The bike is for me to enjoy looking at, so I doubt I will keep it 100% original, but I will hesitate before modifying/ painting any part and keep all the original parts so it can be put back to original with a few hours work. I will try to keep many of the original parts on the bike. I may think twice about painting the airbox and the carb as well as drilling the brake arms just because this is such a rare pristine bike. Everything else can be bolted back on quickly and the bike does need disassembly for proper cleaning and greasing. I have a lot of respect and sentiment for this model bike, except for one part.. the rear shocks which don't deserve to be on a bike of this caliber. I blew out mine in the first 15 minutes of riding out of the dealership and in those first 15 minutes, they were so over dampened that it rode like a tank so they will come off even if I were doing a stock restoration. Don't want to even look at them. Every serious rider had to replace them immediately and it was almost as if the bikes came from the dealer with Fox Shox in those days. the dealers were stocking the Fox shocks to sell with the bikes, I recall.

Bultaco Pursangs are one of my favorite old bikes! Did you at least rebuild the seized engine?

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7/25/2018 7:43 AM
Edited Date/Time: 7/25/2018 7:48 AM

make1go wrote:

unrestored originals in very good condition are imo the ones to have.,..anybody with a lots of cash can turn a bucket of shit into a good bike...

it takes dedication and luck to find the others..

my best eg: season and a bit riden 79 mk10 250 bultaco persang, seized and parked for 25 yrs, still had his race numbers on it, 99% og....$650..

Tokyo_Tiddler wrote:

I would agree with you, but also consider that it takes a lot of cash and lots of hard work to turn a bucket of bolts into a gem. The bike is for me to enjoy looking at, so I doubt I will keep it 100% original, but I will hesitate before modifying/ painting any part and keep all the original parts so it can be put back to original with a few hours work. I will try to keep many of the original parts on the bike. I may think twice about painting the airbox and the carb as well as drilling the brake arms just because this is such a rare pristine bike. Everything else can be bolted back on quickly and the bike does need disassembly for proper cleaning and greasing. I have a lot of respect and sentiment for this model bike, except for one part.. the rear shocks which don't deserve to be on a bike of this caliber. I blew out mine in the first 15 minutes of riding out of the dealership and in those first 15 minutes, they were so over dampened that it rode like a tank so they will come off even if I were doing a stock restoration. Don't want to even look at them. Every serious rider had to replace them immediately and it was almost as if the bikes came from the dealer with Fox Shox in those days. the dealers were stocking the Fox shocks to sell with the bikes, I recall.

Bultaco Pursangs are one of my favorite old bikes! Did you at least rebuild the seized engine?

i had a 78 and could prove it if this forum software worked properly...
error upload 100kb jpeg pic huh?

thats great to hear about keeping the good genuine parts og..

the bultaco well i bought a 76 pursang with an astro spec motor
and put that in.
only raced it once and it flew but the shocks (betor remote res?) were in need of work so i couldnt push it.... all got sold to a friend not long after that....

lol 78/79 cr shocks yes as bad as any production mx bike has come with, they should have only been for doors and tail gates or other such unimportant less demanding applications...took ages for the after markets to make such long 17.5 shocks available and i could only afford the marginably better s&w stroker shocks.

years later when doing vintage mx i ended uo with a couple and while everyone wanted the fox air i got ohlins and felt they were way the best choice then....

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7/29/2018 1:01 PM

That is one well preserved vintage bike right there, nice find !
I agree on not painting over the original paint if it only has some minor scratches and chips. I rather see a vintage bike with original paint and patina on it than seeing something completely repainted and looking brand new.
My point of view is, if something has the original paint and you score it at least 80% good condition, then don’t repaint it.

Looking forward to follow this build Mike, and thanks for sharing with us !

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7/29/2018 4:48 PM

Agree Bryan. I bought 4 different brand of Tahitian red, and none of them are an exact match, so at least this way people can see what the original color was.

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7/29/2018 8:21 PM
Edited Date/Time: 7/29/2018 8:29 PM

wow, that is nice and it would be a crime to do anything to it at all. things are only original once.

how much did you pay for it?

I raced a 74 bultaco 250 and 360 back in the 70's. I had them ported by paul nyland who was a bultaco tuning legend back in those days. I took the external flywheel off the 250 and ran it that way for a while. that made a completely different bike out of it.

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7/29/2018 8:27 PM

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7/29/2018 11:45 PM

Tokyo_Tiddler wrote:

I wasn't looking to start a new bike project right now, having not quite finished a 2001 Japan RC250M project, but came across a really pristine, all original 1979 CR250 near me that was hard to pass up especially since this is a very nostalgic bike for me. It is a bike I raced as a kid and one that I was really fond of.. killer engine.

Here are some pics of the bike the day after I picked it up and not yet washed. I have totally disassembled the bike, and best I can guess is that this bike was gently trail ridden for maybe 20 or 30 hours. The only wrench this bike ever saw was the rear axle nut to adjust the chain. It was pretty clear that the wheels had never been removed from the bike and the original "Claw" tires still had most of their tread left. The grips and levers looked almost the day they left the dealership. Obvious that this bike not only had not been raced, but it doesn't even look like the bike had ever been even in a small crash. The paint on the fuel tank was unmarred and no sign of even the slightest knee scuff marks. The same goes for both unmarred engine covers. The seat still looked brand new.. no cuts or scratches. Most bolts still looked quite new and the trans oils looked pretty good after sitting in a dry place for probably close to 40 years. There was a little bit of fading on the front fender, but other than that, the plastic all looked good. There was no dry rot on any of the rubber parts either which were still supple like new. There were remnants of a mouse nest in the airbox, but this bike is pretty much a time capsule from the past. The few minor scratches on the swing arm and left side plate looked more from having things piled up against it in a garage than riding. This bike is 100% original.. no parts broken or missing, so the conundrum for me is how much to preserve in the rebuild and how much to repaint and replace with cool new parts.






That thing is so nice I would just detail the heck out of it and keep it like it is. Nice find

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Ed Johnson

8/15/2018 12:18 AM

I have the bike all disassembled and I the process of cleaning and painting parts. Disassembling the bike gave me better appreciation of how much.. or how little the bike had been used or seen weather. Here is the underside of the seat. The bolts and seat bracket look like they were just installed yesterday.


This triple clamp stem hardware in the picture is just as I got it.. I haven't even taken it off for cleaning yet. Looks brand new.


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8/15/2018 10:02 PM

Wow, the seat pan really tells the story of a very well cared for bike. The paint would be extremely difficult to match...all colors will lighen or become darker with age, I would think a detailed wax job is all the bike needs...as far as frame is concerned. I unfortunately found that the motor has to come out to get the airbox out, I was a bit bummed about that, but I'm thankful to have the old steed. With so many options for the 78-80 CR's, I'm glad to see you take the rout that you have chosen. Your CR has aged like a fine wine, another bonus is that the bike keeps getting older. Carry on.

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There's something happening here, what it is ain't exactly clear.

8/16/2018 2:18 AM

Tokyo_Tiddler wrote:

I have the bike all disassembled and I the process of cleaning and painting parts. Disassembling the bike gave me better appreciation of how much.. or how little the bike had been used or seen weather. Here is the underside of the seat. The bolts and seat bracket look like they were just installed yesterday.


This triple clamp stem hardware in the picture is just as I got it.. I haven't even taken it off for cleaning yet. Looks brand new.


not wrong as close to new without coming from a crate as you can get, amazing find at this stage of vmx..i started in the early 90s and dropped out around the turn of thr century. things were drying up fast and hard to find stuff was skyrocketing........now of i only i could have held on to them all id have a great stable..but i was collecting vintage synthesizers at the same time and i started to enjoy that more.



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8/19/2018 9:30 PM

I hope the information I post here will greatly help the next guy restoring one of these Red Rockets. The bike was in such good shape, you can see what the original colors looked like in spite of 40 years passing. Even on the engine, I looked under the rubber grommet on the chain guard which was caked with dried chain lube (I don't think this bike was washed or used much) and was somewhat isolated from the engine heat to confirm the original engine color (the cylinder head turns a dark red from the heat and not the original color as it sat in the dealership).

Then I proceeded to track down every paint I thought might match the original colors as closely as possible. I found 4 brands of Tahitian red and further internet research suggested other colors that some people were claiming were close to the original Honda paint such as Ceramic Red, RAL 3020, Chrysler Red, etc. I sprayed 12 different shades of red and compared them to the motor and frame. Here is a picture of 7 of the reds that were closest...


There were only 3 paints that were worthy matches and only one that was really correct. The VMX Racing Tahitian Red, National Autobody & Paint Supply Tahitian red, and LVP RAL 3020 Traffic Red. The Color Rite Tahitian red was so far off, they should be embarrassed.. way too dark for the frame but a possible candidate for the engine. I also tried different matte, flat, and satin finish clear coats to see if that would help with matching the engine color.

In the end the best match for the engine paint was the RAL 3020 Traffic Red form LVP. The RAL paint colors are found in Europe and not so much the US, and while you can find RAL powder coat in the US, you really cant find RAL spray paint except for this one company LVP who noticed the unmet need in the US for a touch up paint for the RAL powder coats. Here is the cylinder and head freshly painted with the RAL 3020 traffic red. It will need to be cured slowly over several cycles of progressively hotter engine temps, allowing it to completely cool between cycles.


For the slightly lighter colored frame, the Tahitian red from National Autobody & Paint Supply was a dead ringer except it only comes as a base coat which is a flat finish and needs a gloss clear coat. This is not a problem. 2nd place goes to the VMX Racing paint which is a so so OK match though not exact. It is a little darker. It has a gloss finish so a clear coat is not necessary. Here is what the National Autobody & Paint Supply Tahitian red + gloss clear coat looks like next to the original frame paint. Finally an exact match! I will use it for touch up and for the swing arm..


mike

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8/20/2018 2:14 AM

Takes some serious dedication in trying out all those different types of paint !
I was going through the same process, but my standard was at least a 95% match. I need to paint my chassis, subframe, swingarm and airbox in tahitian red to match the fenders i bought.

Luckily i didn’t had to spend much on different spray paints, because the first and only spray can i bought was close enough for my standard.

What are your thoughts, would you accept this match or not ?


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8/20/2018 2:35 AM

Well those 2 parts certainly match, Bryan.. What color is that? Always hard to tell colors on a computer screen, but it looks a little dark compared to Tahitian red which is a little orangey.

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8/20/2018 3:23 AM

Tokyo_Tiddler wrote:

Well those 2 parts certainly match, Bryan.. What color is that? Always hard to tell colors on a computer screen, but it looks a little dark compared to Tahitian red which is a little orangey.

The fender is tahitian red, but it’s a reproduction fender. So it will certainly have a slightly darker color compared to a NOS OEM fender. The spray can is traffic red. Both parts match enough to be satisfied.

Are you going to ride this bike when it’s all finished up ? Just incredible how that machine survived all these years ! Imagine this low hour bike being stored away in an old dirty humid shed in the backyard, sure it wouldn’t be in the same perfect shape. Previous owner did a great job preserving lol.

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8/20/2018 6:07 AM

Oh.. I thought those parts were painted together because that looks to be an exact match! The 3020 Traffic Red is certainly a shade or two darker and a little more red, but somewhat similar to the Tahitian red.

I may ride once or twice at the VMX race at Unadilla. I don't really ride much anymore (and shouldn't) since I broke my back.. so this bike is mostly to look at. I think she was in a warm dry climate controlled garage with a blanket over the tank and seat.. the hardware on the bike isn't even tarnished.

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9/9/2018 4:29 PM

I haven't posted in a while but have been busy cleaning parts and collecting the new parts that will go on the new build..
Here is the rear motor mount bracket fabbed for me by Ray Carlstedt. It will receive a polish before going on the bike.
Ray is the only guy I know making these. It is a nice piece and he is great to work with...

I got a ton one parts from Phil and Stevie Denton including all replica HRC bolts. Here is a fancy looking upper motor mount bracket from them..

Here is an RC-replica swingarm spindles, stainless RC replica motor mount bolts, and a CNC exhaust flange that will prevent spooge dribble typical of the stock bike.

I found a set of vintage D&G front fork air caps. I think they may have been anodized blue originally, and I could have re-anodized with the anodize tanks I just set up, but I felt that it wouldn't look right on this bike and decide to give the caps a fresh polish. They can be a good way to add a little more tune-ability to these old forks with a couple of pounds of air..

The fuel tank is already to go on.. the original paint just needed a fresh polish, the left hand Honda decal had a tear so I replaced the decal, a fresh NOS o-ring on the fuel petcock, and I put on an RC replica white gas cap from Holly in Japan..

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9/10/2018 12:09 PM
Edited Date/Time: 11/6/2018 12:24 AM

Carb was disassembled, ultrasonic hot tanked and assembled with new gaskets with a light polish. The ultrasonic cleaner took the dark gray paint off the carb cap, so I found an NOS one..

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9/10/2018 12:10 PM

were the original carb vent lines pink or clear?

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9/14/2018 9:57 PM

Guys,

Any tips on the best way to accurately cut the large holes in the rear and front VMX Racing fenders? It is a PIA they don't come with the mounting holes. Was wondering if I should try to put the old fender up against the VMX fender to mark the hold location or to fold the fender in place on the bike to mark the holes. Not sure which would be more accurate.. I am trying to avoid crooked/ slanted fenders since it will require several size drill bits to work up to that size hole, or is a hole saw the better way to go?

Thanks,
mike

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9/14/2018 11:05 PM

Mike I would use a stepped drill bit. The ones that look like a triangle - the hole gets bigger as you drill further

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9/15/2018 7:00 AM

Question - Since Honda produced the bikes with slightly darker engines paint than the frame, does anyone know if the engine assembly was done at a different Honda factory than main assembly?

The reason I ask is we have have similar issues in our business. We have internal and external suppliers all over the world who provide us with painted parts. Some of those parts aren't an exact match to the paint coming out of our paint system, but they are close enough that they fall within the "paint standard spec" therefore we pass them. To the untrained eye, most can't tell there is any difference in the shade. Of course we provide them with our standard color spec, but there are many variables in the final color especially when the liquid paint is sourced from different companies

Just wondering if this was a similar case where Honda brought in the assembled and painted engines to the main assembly factory where they had less control of the red shade. It's likely that the frames were welded and painted within the assembly factory but I think it's fairly likely the assembled engines were coming from a different division.

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9/15/2018 10:13 AM

swatdoc wrote:

Mike I would use a stepped drill bit. The ones that look like a triangle - the hole gets bigger as you drill further

Thanks Swat Doc. I am also sending the original fenders out to Phil Cox at Plastic Restorations. If I ride the bike, I wil use the VMX fenders and put the originals back on for display.

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10/9/2018 5:05 PM

Holy shit are you lucky to find that! Great build and the best bike I ever owned....well favorite anyway lol

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Chuck Norris is 1/8th Scottish. This has nothing to do with ancestry, the man ate a fucking Scotsman!

10/15/2018 3:14 PM

Mike,

The stepped bit is the best way to drill the holes, Harbor Freight has these in stock.

I HATE having to figure out the exact placement of the holes........until I took an old beat to death fender and cut out the mounting holes so they fit into the pocket of the VMX fenders. A sharpie and and I am off to the races with accurate holes cut in my new fenders. I also marked the templates right and left to help speed up the process.

I also test fit the bit into the old fender as it is surprising how much bigger the hole needs to be than one thinks. I just use blue painters tape to mark the bit for the depth.

Richard

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10/15/2018 3:49 PM

Thanks Richard. The OEM holes measure 17mm in diameter. The VMX fenders are slightly wider than the OEM fenders which somewhat fit neatly inside the VMX fender for marking the holes. I used 3 straight drill sizes up to 12mm and used a step drill to increase the size to 17mm. I went slowly and also kept checking the fender on the bike.

I am also having the original fenders refinished as we speak.

mike

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