Vintage Dirt Bike Q & A

I traded a Yamaha PW50 for this bike somewhat accidentally @ 3 weeks ago. I put an ad in Craigslist B'ham Alabama asking for a fixxer-upper XR70/80/100 to replace the PW80 as my son had outgrown it. I had had the PW for @15 years-it was the first year offered. A man called me asking if I would be interested in a CR80R, 1980 model. I asked for pics and 48 hrs later we traded.
Here is a few pics of "BEFORE," as well as what it looked like 2.5hrs later after my 9-yr-old and I compleetely disassembled it. Motor had NO compression and the prev owner told me "someone had put a new piston in it but it still did not run..." After pulling head I saw why--brand spanking new piston with the used rings on it!!! SO i have ordered a Wiseco overbore piston (50.00mm) bottom end looks good.
Motor also interestingly had NO base or head gasket...piston ringls looked good and cylinder walls looked perfect--no scoring or scuffing at all. I considered just putting a new set of stock rings back in and honing it and seeing what kind of compression numbers I could get out of it but then changed mind and decided to do it right for sure first time with new piston/rings/wrist pin.
Generally it whas complete MINUS the rear plastic side panels and the airbox cover.

I am going to replace the following due to wear, damage, or age...most already ordered unless specified otherwise
Piston/rings/wrist pin
Brake cable (rusted-won't move)
Clutch cable (rusted-won't move--but clutch arm moved fine)
Handlebars (stock bent w/crease badly, using Renthal CR80 bars--not stock/OEM I know but
much thicker walls and look nice--only NON-STOCK part we will have on it!)
Grips--got NOS at a vintage swap meet.
Front number plate- " " " " same swap meet
Seat cover--still looking
Inner tubes-- tires actually very good still and not dry-rotted
Chain/Sprockets- going with stock replacements teeth # on front and rear for now
Front brake lever- was broken and replaced with wrong one and it was broken also

SO far I have had the frame and swingarm and foot peg mount sandblasted and epoxy primered Friday morning--waiting for paint to come in Monday/Tuesday. Tank is also sanded down-small ding repaired and in primer waiting on paint also.
Have also sanded/stripped all black parts on bike (brake strut,shifter lever,triple clamps, etc) and repainted black and baked them all. ALthough I DID strip and polish and clear the top part of triple clamp and the handlebar brackets to match the aluminum bars--did bottom half of clamps back to black.
Carb is rebuilt (actuall clean as a pin when I opened and no corrosion/green gunk--for a change...usually mine look like the dud's that redoing the $80 MR125 when I bring them home to start restoring) but ran into an issue on it--someone tried to unscrew the enrichener fitting where it screws into the carb body and broke the hex portion of the brass fitting off--NOT GOOD!!! still trying to figure out how to deal with that issue as it is broken off below the top of carb body so cant unscrew it nor can I get the enrichener shaft out to then easy out the fitting....HMMMMMMMM...gotta think about that some more. WIll do a seperate thread on it as carb is a carb and other bikes may have had similar problem.
I will include some more pics of different stages of process in the thread for reference for others doing similar projects. WIll have to come up with side plastics and an airbox cover here in USA--apparently seem rare and expensive so far!!!

ANd here it is taken apart a couple hours later.....

Here are some pics of misc. painted parts. I have also taken every single nut and bolt and washer from the bike and run them on the wire wheel to remove an rust/corrosion/residue. The rims were a little rusty but 99% of it was surface--it came off with a 0000 steel wool pad and water. A few rusty spots were pitted some but by no means severly.....the rear wheel is in need of cleaning and also as you may see in the pic if look closely, someone wired EVERY SINGLE place the spokes crossed each other---never seen that before. Could it be because they were loose maybe? Any ideas or explanation is welcome on that one.....

You can see Renthal bars I am using a polished/cleared upper triple clamp in this pic also.

The kick starter had lost its ability to fold in/out, so I disassembled it and cleaned and greased the little spring and ball/groove and WOW! what a difference--better than new I think!

Forks were in very nice shape also with VERY minimal pitting or rust--and none of it in the travel area fortunately. Polished them out nicely and replaced the fluid also so they ready.

Need to take rear springs off the shocks so can clean them well. I dont have a little mini spring compressor--any body got an idea how to do that also? Thanks DOUG

PS-will post pics of frame/tank/swingarm when get it back next week. Found some DG/Honda tank decals and was thinking of using them instead of the Honda only tank decals.....any thoughts?

just because it had old rings doesnt tell me its the primary reason of not starting. hearing about the lack of gaskets makes me think that the guy did a lot more to it, that he really didnt know what he was doing. i would give everything a REALLY GOOD going over. you dont want one little oversight cost you another dis-assembly. who knows what it could be missing as well. i learned the hard way. re-insstalled a tranny and missed a washer. about 20 seconds after i started it, i was reminded expensively. good luck!

Sweet little bike....looks exactly like its big brothers.

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Garry Mainer
#33m (retired)
Honda Cr250r 1980
Honda Cr250r 1980
Yamaha TY250C 1976
Arctic Cat 650 H1 2007

i would recommend you to put the hole engine apart and renew all bearings and seals.
they are all industrial standart sizes and not very expensive.
in my engine i´ve found sand and some piston parts behind one crankbearing.

_________________
80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

I probably will pull motor down and go thru it--going to finish rest of it all first as the motor is rather simple to deal with.

b-joe: I notice yours is listed as a 1980 yet you have a boxed aluminum swingarm and a different exhaust silencer than OEM shows--my manual shows 80-81 with tubular swingarm painted orange like frame while 82 has those plastics with aluminum swingarm....? Did you change that out?

the swingarm is an original 81 made out of steel, it´s just silver painted.
it was at the bike when i got it. the swingarm is the main difference between 80 and 81, and other decals and seatcover.
were after an aftermarket alu swingarm earlier this year but didn´t got it.
the muffler is an aftermarket part for a modern kx85 or cr85, don´t remember.
this one is repackable and i welded it to the orig. muffler tube.
the orig. muffler was too loud cause of the old oilsmack in it.
plastic is also original exept the rearfender.
didn´t find a good one so i cut a part of an old cr250 80 frontfender and screwd it to the seatbase.
better than nothing.

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80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

Got my parts back today--painted back to original--the tank looks SWEET! Can't wait to start putting it back together! Here a few pics.....

Hey-- if that was your CR80 "before" picture you get the prize for being obstinately determined to take something from nasty to awesome....nice work...LOVE me some "before/after" pics...will keep you all posted with pics on progress.

I am missing only the side panels and airbox cover....still looking

yes, it´s the before pic. thanks for the prize.

got the last missing part today, the frontnumberplate.

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80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

OK--got frame hung in shop sling and started re-assembling it last night. I had originally dropped most of the ball bearings from steering stem onto the floor when I removed it and thought they were lost and gone forever----but miraculously (you would understand that better if u saw my shop floor...!) I located all 42 of them down there so was able to reuse after thorough cleaning--the race and cone and balls were in great shape so did not want to have to spend the $$$ on new bearings if could avoid.

Got steering stem back together and triple clamps and forks installed. Put CDI/electronics back in frame stays and mounted handlebars and footpegs and rear brake pedal. Also installed swingarm temporarily. I have to take rear springs off shocks to clean thoroughly yet before installing them to frame/swingarm and dont have a spring compressor that will fit yet--may have to rig something...? ANybody got an idea other than the Honda tool to compresss that spring?

I am waiting on rear sprocket and inner tubes so can finish up wheels to install them. ALso waiting on brake/clutch cables and a clutch lever. Kind of at a standstill for now. I also need a grommet for the gas tank--I have 2 of the 3 rubber ones for it. WIll prob use them on front and go to Home Depot/Lowe's they have pretty large selection of rubber grommets should find one that will fit ok for rear tank mount bolt hole.

Here a couple pics of frame hanging--MUCH easier to assemble this way if you have never done it--just a couple eye hooks in beams overhead and use two Ankra type tie-downs to nylon straps--you can raise and lower it very easily as you work on it at comfortable level until you reach rolling chassis status---just an FYI...

Will keep posted as I go--DOUG

looks good, but sorry you installed the swingarm in a wrong way. turn it up side down.

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80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

Yeah, noticed that right off after shooting pics! It switched over now--I was dry-fitting a shock and realized I'd put it on there upside down! Have to remove it again anyways for engine install, so....will post more pics tonight --got it mostly together minus wheels/engine last night.

Waiting on brake/clutch cable, f & r inner tubes, and sprockets/chain to make it a roller--then will go through engine.....new piston/rings/wrist pin should be here soon also maybe today or tomorrow.

Ordered new clutch/front brake/throttle cables today as well as front and rear inner tubes for tires and a chain/sprocket set. I decided to go with the stock 14/47 sprockets for now. Primary reason is the desire to be as original as possible with the whole project.

Any discussion or opinions on that 14/47 or 13/47 combo w/ a stock motor?

b-joe: also notice your tank graphics are 1980 NOT 1981...any reason or just availability?

I saw some DG/Honda tank stickers that looked interesting. But was looking at getting OEM style graphics from here:
http://www.vintagefactory.com/1980%20CR80%20Decal%20Page.htm

And also does/has anyone ever ordered plastics from these guys at this website? Am looking for some side panels/plastics for this cr80...
http://www.reproductiondecals.com/default_frameset.html?kaw_3.html~main

thanks DOUG

as you see in the pics before it´s an 80´s frame and i wanted the 80 look, but the tank was an 81.
so i striped off the white sticker and polished the tank. the bike will not stand in a showroom it´l be used by my niece.

you can get the plastic direct at dc plastic, note these are repros, quality and surface are not as good as the originals.

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80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250