Honda C50 `restoration' [Archive]

xwhatsit

14th April 2009, 15:48

I put `restoration' in quotes because it's not really, it's just rebuilding an old shitty Super Cub so my sister can ride it to uni and back.

I wanted to keep the red but sis specified dark blue... so now I'll have to buy lots of `Honda' badges to stick everywhere so people won't think it's a Yamaha V50. Had some spraycans mixed up from Colorworks in Mt Wellington/Penrose, cheap as chips, have one spare in case of the inevitable drop while learning.

Plastics were dirt-cheap from Thailand, seem good quality with the exception of the RHS sidecover which I'll have to file down to fit.

Tail was the biggest pain in the arse, rust all through the thin metal mudguard (which is welded to the frame so can't flog a new one). Lots and lots of bog :sweatdrop New swingarm, old one was bent, sure to improve the handling!

Painting is done now, got better as I went along. Now just need to get new speedo (bought one but it's from a later model that is too wide despite looking almost identical in pictures, original one is broked), tyres, brake shoes, grips, mirrors, sort out the electrics (head/tail lights and horn go but no indicators), figure out the throttle (it's got a funny spiral system in the handlebar, at any rate it's flogged out and rooted) and numerous other things. Bought the ex a sewing machine for Christmas, now I get to ask her to make a new seat cover. The bottom half of the chaincase was missing and the top half is fucked, so I will have to locate one of those but it's not essential, really.

If anybody has any parts or literature I'd love to hear from you!

GerryAttrick

15th April 2009, 07:24

Keep those stories rolling - my wife wants a step thru just like that one.

Don't forget some pix when its finished

James Deuce

15th April 2009, 07:27

Totally awesome man. Is your sister still getting her hands dirty?

Big Dave

15th April 2009, 12:11

>>so people won't think it's a Yamaha V50.<<

.........somebody thought of the children.

carver

15th April 2009, 12:32

i might be able to find a old cub if anyone is after one

tri boy

15th April 2009, 12:38

Nice wk Xer:yes:
The m/cycling gods will reward you in the future, for putting the effort into an old classic like that.
:scooter:

xwhatsit

15th April 2009, 15:48

Hah, Jim, while she's quite good at taking things apart I'm going to exercise some caution with the reassembly :laugh: I'm dangerous enough! No she'll definitely be involved as possible, need to teach her a few things anyway like oil changes and chain maintenance.

Looks like Econohonda might have the bits I need to finish it off. Hopefully the little slider inside the throttle will fix the problem it has (keep turning the throttle back and it'll go past the stop and jam... such a silly design for a throttle, not at all like the rest of the bike, needlessly complicated and prone to wear). Can't wait to ride the thing again, it's such a happy wee bike.

Pics: Left -- what I need; Right -- what I bought

Squiggles

15th April 2009, 17:12

i might be able to find a old cub if anyone is after one

Hell yeah :headbang:

carver

15th April 2009, 17:14

Hell yeah :headbang:

tis a bit rusty....
been out in the rain for a bit

xwhatsit

21st April 2009, 01:33

Yay, I got the horn going, felt I deserved a beer after that.

Anybody know if the lights should work without the engine running? I haven't installed it yet.

On another note the front fork is definitely bent; could only really see it after putting the front wheel in place with the mudguard and turning the whole shebang upside down. Will have to acquire a new front fork, no rush, it's very agricultural and leading link so it won't explode or anything. Considering the (rather worse off) swingarm I think it might've had a bit of a munting down the left hand side at one point.

Ixion

21st April 2009, 10:17

Anybody know if the lights should work without the engine running? I haven't installed it yet.

Not on the early models. Battery was horn and indicators only, lights ran diretc of the flywheel mag. Dunno about later models. Is it OHV or OHC ?

xwhatsit

21st April 2009, 10:46

OHC. According to a Pomgolian Cub forum I frequent I won't have any lights (got a reply this morning). I didn't have indicators before and I still don't have indicators now. Might be that little magic box that does the flashing tickity-boo, everything else traces fine.

Motu

21st April 2009, 17:42

I don't think they ever changed - mine was 1981...battery does horn,indicators and brake light.It might pay to be in neutral at the lights with the revs high at night....bikes have been rear ended at night with only a glowing tail light at idle.

I had a lot of trouble keeping my indicators going,but a 12v electronic flasher unit solved it.I think the one I used was banned - they would keep the indicators flashing no matter the state of the bulbs,which is not a good safety feature.

xwhatsit

22nd April 2009, 13:10

Well after fiddling around trying to trace the problem I now have nothing at all. Battery is putting out a nice 6V or so (yeah it should be higher but I haven't given it a proper charge yet, I'm just using it to trace the electrics). I had a nice horn before but now I'm only getting 0.2V through the ignition switch and the horn rang for about half a second then stopped forever more.

I think the indicators were down to poor earthing. What is the funny resistor (old-school resistor, wire-wound with green material shielding) which comes out of a pink wire and goes directly to ground all about?!

But this new problem is something different altogether. Oh how I hate this stuff.

EDIT: Sorted it, wiggled some wires around and one of the ones which go into the ignition switch connector fell out in my hand. So I delved into the trusty spare CB250RS wiring loom and found a switch that had the same size connectors... winner. Still don't know wtf this magic resistor is all about though, and I still have no indicators but it's time to go to class.

The resistor is up the top of the attached diagram, see how it just goes straight to ground? Is this where I get my ground from? Because apart from the ignition switch (which doesn't really have a ground, it's attached to nothing at the moment and will have a plastic bracket), how does the negative on the battery reach ground? Do I need to run a ground to the ignition switch perhaps. If not, wtf is the resistor for :eek:

tri boy

22nd April 2009, 14:42

looks like a voltage resistor for the charge/light circuit.
(allowing for current variation when lights are on, or switched off?).
Been a while since I butchered/worked on Honda AC lighting systems.
Measure resistance across it to see if it is burnt/damaged.
Got no specs to throw your way.
Soz.

Ixion

22nd April 2009, 19:43

The key to this is to note what ISN'T on the wiring diagram. To wit, there is NO voltage regulator , in the normal sense.

The resistor acts as an unspeakbly crude voltage regulator, to stop the alternator overdoing things when the lights are off . When the lights are off, the alternator output at C1 on the lighting switch is switched to the resistor and to earth. When the lights are on, the alternator output is switched to , duh, the lights.

xwhatsit

22nd April 2009, 20:44

Excellent! I love it!

So that's why it's wired into the headlight switch. My feeble compsci eyes couldn't follow the wires.

So I still don't know where the earth comes from (from the battery negative), I think I'll have to run a wire from the ignition switch. I don't think it's the original ignition switch (way too many wires, much more htan necessary, but they're not all connected) and the bracket is broken.

Motu

22nd April 2009, 21:45

So I still don't know where the earth comes from (from the battery negative),

Earths don't come from anywhere - they go somewhere.....unless,gulp,you are a follower of the heresy that says electrons flow from negative to positive! May you be struck down with a bolt of lightening from the ground!

xwhatsit

23rd April 2009, 00:24

Earths don't come from anywhere - they go somewhere.....unless,gulp,you are a follower of the heresy that says electrons flow from negative to positive! May you be struck down with a bolt of lightening from the ground!
<img src="http://imgs.xkcd.com/comics/urgent_mission.png" />

Anyway I figured out why a) I don't have a connection from frame to negative battery, and b) why the engine sometimes didn't want to turn off when I switched the key off (had to stall it in gear, sometimes tricky with the auto clutch). Because the casing on the ignition switch is all broken, there is no connection from bracket to ignition switch (that little metal bit which goes around the bolt hole) and the tabs which hold the switch together aren't there, so the base of the switch pushes out a little unless you squeeze it back in. If you squeeze the base right in, it'll work every time.

So I ordered a new switch off eBay, $US10 for a knock-off, of course it means two keys now, one for the ignition and one for the steering/helmet locks.

Soldered up a tremendous amount of broken wires and connections. Even those little spring-loaded Stanley lightbulb sockets, the cap popped off that connects the wire to the bulb contact (and holds the spring in), so I had to solder that back on too, fiddly as all hell. Can't test my nice new wiring as all four of the indicator bulbs had blown before. Note that using a 12V 3W dash bulb as a testing light doesn't make the indicator relay want to flash; hopefully the correct wattage will get me what I need.

Nearly ready to start bolting everything back together.

xwhatsit

23rd April 2009, 22:07

Woohoo, engine back in frame, nice big blue sparks too! Shame I still get nice big blue sparks with the ignition turned off too :lol:

Motu

23rd April 2009, 22:15

xwhatsit

24th April 2009, 21:53

By the way, for anybody pulling one apart, this will be useful: http://lostabout.com/C70_65_50_manual/

Now that's a proper workshop manual! Even Haynes don't do such a nice manual, and this is OEM.

tri boy

24th April 2009, 22:10

What you need is a ''Villiers'' kill switch - a peice of strip steel bolted to a head bolt.With your bare finger you push the strip of steel against the bare sparkplug terminal,and the engine dies.....or you die - I can never remember which one it is.

I remember those things. Came fitted to Wisconsin stationary engines, with magneto's.
Scared the shit out of me until i got used to them. (Push down hard, and don't ease the finger pressure off till it was well dead).
Funny how none of my mates would have a go.:baby:
Starting the beasts was even more fun. Pull cord, and devil may care lunge.
Aaah, sweet memories.

xwhatsit

26th April 2009, 01:35

Woohoo, put some wheels on it and poured some petrol in the tank... off it goes! I should do the valve clearances, set the points, give the carb a clean too... but performance isn't bad as it is. It screams right out in second gear, valves bouncing, hook third and off it lunges again. Hit an indicated 65kph on the flat which is great.

Now for some new tyres and to finish off the seat cover.

xwhatsit

26th April 2009, 16:14

All right! Just a few bits and bobs that need doing now, like sewing up the seat cover and finding some mirrors etc., but it's near done. Need some new tyres, 2.25-17 front and 2.50-17 rear... some nice Chen Shings on tardme at $26 each but they're 2.50-17 fronts only. Would put a front on the back (4hp isn't going to kill it) but a 2.50 on the front is a bit big. Oh yes and a new exhaust wouldn't kill it, this one is shagged, but that can wait as funds allow.

Got my sister on it today, it's for her to ride to uni and work, so had her doing figures of eight in the street and even went for a wee pootle down the back of Ambury Farm and back. Hooked third gear even and scraped the sunny side of 40kph!

Ours is a 25yr+ Honda garage only.

tri boy

26th April 2009, 16:33

Going by that Cheshire Cat type grin on your sis's face, I would say she is stoked to have a bro who can twirl a spanner.
Well done.:first:

R6_kid

26th April 2009, 17:39

Dude, you never said you had a hot sister! :shit:

xwhatsit

9th May 2009, 00:17

Dude, you never said you had a hot sister! :shit:
You ride Hondas too, why would you be interested?

I got some mirrors from Wellington and some new tyres from Christchurch to replace the old bald ones. A bit disappointed with the price of the tyres, I saw 2.50 fronts and 2.75 rears for $26 apiece, but he wanted $35 and $45 for a 2.25 front and 2.50 rear. I'm not sure I want to pay that much for a tyre regularly :oi-grr:

Nice tyres, Kings Tyre, soft rubber... 2 ply nylon, should last a while... rib pattern front and block pattern rear.

I've just changed the front. Didn't use any tyre levers (I still haven't got around to buying some), getting the old tyre off was the hardest bit, I had to use a 10mm ring spanner, slide the ring-end around to get the first side over. Putting the new tyre on I did completely by hand with a lot of puffing and panting. I didn't get new tubes, forgot about that, the old tube has a patch but it looks like it's held for years so I'll just leave it for now. Put some air into it tomorrow and see if it'll bead, service station is closed now and their hose put away.

Noticed the rim has a little pinhole of rust in it on the front. May have to look at getting some new rims and spokes... cheap in Thailand. I've spoked a 250RS alloy, that wasn't too hard, although I can't vouch for it being true. Probably not a good idea to run on the rim but it's in one small spot, the metal is very thick and solid apart from this tiny little dot (I think the bike sat around for years, maybe a bit of water pooled at the bottom of the rim?), and it's not exactly under a lot of stress at 55kph and 70kg bike.

Ignition switch arrived from Thailand too, so can wire that up and then find some indicator bulbs. BA15S is what I think they are, where on earth do you buy 6V lights from? Repco has nowt. Maybe I should just ring Malcolm at Econohonda, can't imagine they'll be too cheap though. Dicky little tail lamp bulb as well.

Motu

10th May 2009, 22:57

xwhatsit

11th May 2009, 00:02

You could use LED bulbs - I know you wouldn't pay money for them....but you could gut a case and solder in an LED and fill with epoxy.Just to keep with the theme y'know...

Have you been following this? -

http://www.advrider.com/forums/showthread.php?t=460631
I may have a lead on some bulbs...

Rear wheel is rooted too. Rear wheel bearings stuffed and a couple of bent spokes (a few seized nipples as well). Don't know why I didn't notice this before.

Anyway I've asked a bloke on the Shore with a garage full of horizontal singles for some wheels... he's got a front wheel with a stuck brake plate (how does it get stuck?! I suppose I'll find out, provided I can get it loose, what on earth) and a C90/CT90 rear wheel. Hopefully will fit the C50, we'll see. Both wheels seriously cheap so I'm not too fussed.

So I'll have to remove and refit the tyres again. Good thing it's a piece of piss, everybody should learn how to change tyres with these little 2.25/2.50 17" hoops. Maybe it's because the bead is designed for tubeless rims or something...? Not like fitting modern tyres to my RS. At least that's what I heard.

No I haven't seen that thread... I'm following it now! Although I don't rate it, that bike has telescopic bloody forks! I like the front tank, though. With the way these motors sip gas (110cc or not) you could ride for weeks at a time :laugh: My mum and sister went to Vietnam and Cambodia a while back... they said they saw `fuel stations' on the side of the road that were little more than thatched shacks. They sold fuel in old Coke bottles.

Voltaire

11th May 2009, 07:32

6 volt bulbs, try Qualitat Motors in Station Road....pre 67 VW's run 6 volts.

Also have you tried Kingsland Honda....its sort of closed and has odd hours but Lloyd has parts and has been around Hondas forever.
no eftpos and does invoices by hand...with carbon paper!!!
I spent lots there in my youfff on an SL 125 rebuild.....

dnewpix

13th May 2009, 09:57

The ignition switch should have an earth connection plate behind the plastic bracket, (from the green wire) which is active when you tighten up the bolts to frame.
The resistor is part of the lighting protection and is used to dump a power surge when starting the bike up with the parking light on. Avoids blowing the bulbs. Make sense? Bike is looking good. Keep going. The ignition switch is a b'stard if it f**ks up. Suspect it whenever you get real mysterious failures... DN

foamy

1st June 2009, 21:57

Came back from Cambodia and Vietnam trip 2 months ago, petrol still being sold in glass bottles on the road side. C50's everywhere, pic is market in Phenom Phen.

xwhatsit

1st June 2009, 22:22

Heh! Awesome!

I should post some more pics. I finally finished sewing a rather home-made looking seat cover. Not really happy with it. I think I was a bit brave to attempt two-tone white/black, as it shows up my (assymetrical) seams rather badly... May just end up buying one from eBay perhaps. I'll leave it as is for now.

Found some bulbs, there's a younger bloke at Michie's Automotive on Como St (Takapuna) who was really onto it and helpful. Not cheap (the expensive one was the tail-light lens) but at least I didn't have to order from overseas.

One slightly annoying thing is that the indicator flasher, which is an aftermarket electronic one, stops flashing at high RPM when the genny is pumping out serious (:laugh:) juice. The bulb wattages are in spec for what it says on the flasher body, so mebbe just too high a voltage...? Bit of a pain in the arse. I might try another flasher if nobody has any other ideas.

I still need to get around to fitting my `new' rear wheel. Only reason why I haven't done it is it needs new wheel bearings and I'm fucked if I can't knock the old ones out. Might need some heat, or to take it to somebody with some serious hardware. At least the wheel bearings are cheap... 6301Z... saw them for $4 each in Australia and almost as good here.

Motu

2nd June 2009, 17:55

[QUOTE=xwhatsit;1129238574
One slightly annoying thing is that the indicator flasher, which is an aftermarket electronic one, stops flashing at high RPM when the genny is pumping out serious (:laugh:) juice.[/QUOTE]

So when you chop it down a cog to back it in....it valve bounces and the blinkers stop working? Oh,I can feel your pain.

I used to like pushing the C50 hard in corners....and the extra load of cornering would load the motor and it would slow the bike down.The subtleties of riding a small bike hard.

xwhatsit

2nd June 2009, 23:33

So when you chop it down a cog to back it in....it valve bounces and the blinkers stop working? Oh,I can feel your pain.

I used to like pushing the C50 hard in corners....and the extra load of cornering would load the motor and it would slow the bike down.The subtleties of riding a small bike hard.
Yup!!! I'm running the tyres at 32+ psi front and back -- way over recommended level, but it seems to hold speed better when going around long corners. Even my CB250RS does that (lose momentum if cornering near 100kph when the power is running out). Right now I'm still a bit frightened of the suspension to really push it. I had the suspension bottom out while banking around a corner and the footpeg (non-folding, remember!) grounded in an abrupt manner which I didn't like. I read a forum post about a UK bloke with a C90, grounded a footpeg and it dug in and the whole bike pivoted around and spat him off :laugh:

I find the engine braking a little severe at 50kph to try changing down to second to hit a corner... maybe on a gravel road... it's begging for a proper manual clutch though so you can feather the downshifts. It's begging for a manual clutch in general really.

I'd really love to lay my hands on one of those SS50 lumps, another gear (or two, they did a 5 speed too didn't they) would be really useful as well as the clutch.

Indiana_Jones

4th June 2009, 12:42

How old's your sister? ;)

-Indy

PeteJ

4th June 2009, 14:15

[QUOTE=xwhatsit;1129240494]

I find the engine braking a little severe at 50kph to try changing down to second to hit a corner... maybe on a gravel road... it's begging for a proper manual clutch though so you can feather the downshifts. It's begging for a manual clutch in general really.

QUOTE]

Hey, Tom, my little '61 has a foot clutch, I've discovered. If you press lightly on the gear lever, but not enough to change gears, it works the clutch. But then, you may as well slide the tail out on gravel, anyway...(mental image of major roosts...).

xwhatsit

4th June 2009, 22:06

How old's your sister? ;)

-Indy
Aren't you engaged or married or some shit? :eek:

Hey, Tom, my little '61 has a foot clutch, I've discovered. If you press lightly on the gear lever, but not enough to change gears, it works the clutch. But then, you may as well slide the tail out on gravel, anyway...(mental image of major roosts...).
Yeah I think that's how it can shift gears. A while ago I discovered Honda's website... they've got some quite cool literature on there. All very self-important and self-serving of course but fun to read nonetheless. Here's an article about the Cub: http://world.honda.com/history/limitlessdreams/qualityproducts/text/01.html

In there they describe how they came across the clutch design. At any rate, the clutch is just a simple centrifugal-type (except still with clutch plates). But if you want to shift gears you still need to disengage the clutch... so they added a manual release (http://www.dansmc.com/hon_ct90_shifter.jpg) which comes in when you press the gear lever. I discovered this early on when the bike was still a wreck; that's how I smashed the original tail-light, by holding down the gear lever in first gear, revving the engine, then letting go of the lever. Pulled a spectacular wheelie all the way up (the stunt riders call it a `12-o'clock') and over the back :blank:

It's a little abrupt though. My left foot isn't used to `feathering' things, as I don't own any British motorcycles (not that a rear drum brake needs too much subtlety... hydraulic disc brakes are such a pain) and I've never driven a car... so maybe that's why I can't slip it nicely :)

One thing I should ask while I've got the attention of some past and present owners; I'm a little concerned about the front suspension. I found when I hit the brakes it becomes very vague. So I found that if I hold the brake on (while it's at a standstill) and twist the bars from side to side the whole front wheel can twist around between the leading links (i.e. one side can compress more than the other side). Perhaps the bushes locating the front shocks are stuffed -- but is this normal behaviour? Surely it must put a lot of load on the wheel bearings.

The rear shocks have no damping and look nasty so I'm sourcing some more. I think OEM will be just the same so I'm having a look for some aftermarket units with a bit of oil in them. I see a lot of the Thai bikes have fancy chromed coil-over units. For the moment I'm glad it's got a seat with lots of cushioning :D

Ixion

4th June 2009, 22:08

Aren't you engaged or married or some shit? :eek:

Yeah I think that's how it can shift gears. A while ago I discovered Honda's website... they've got some quite cool literature on there. All very self-important and self-serving of course but fun to read nonetheless. Here's an article about the Cub: http://world.honda.com/history/limitlessdreams/qualityproducts/text/01.html

In there they describe how they came across the clutch design. At any rate, the clutch is just a simple centrifugal-type (except still with clutch plates). But if you want to shift gears you still need to disengage the clutch... so they added a manual release which comes in when you press the gear lever. I discovered this early on when the bike was still a wreck; that's how I smashed the original tail-light, by holding down the gear lever in first gear, revving the engine, then letting go of the lever. Pulled a spectacular wheelie all the way up (the stunt riders call it a `12-o'clock') and over the back :blank:

It's a little abrupt though. My left foot isn't used to `feathering' things, as I don't own any British motorcycles and I've never driven a car... so maybe that's why I can't slip it nicely :)

Meh. They stole it off Triumph (slick shift in the 50s) and Jawa - had it since about 1000 years.

xwhatsit

4th June 2009, 22:20

Meh. They stole it off Triumph (slick shift in the 50s) and Jawa - had it since about 1000 years.
Ya-vah don't count because a) they're not Japanese and b) the engines don't even have a camshaft or valves or anything resembling a proper motorcycle :bleh:

That slick shift sounds interesting. Website I found reckons it was highly unpopular so they put a normal box back in (apart from a racer who liked it as he could hold his foot on the gear lever until the flag dropped -- just like me pulling wheelies :chase:). I can see why it'd be unpopular... makes for a heavy clunky gear change at least in the Hondas.

Ixion

4th June 2009, 22:26

Ya-vah don't count because a) they're not Japanese and b) the engines don't even have a camshaft or valves or anything resembling a proper motorcycle :bleh:

Y' reckon? So, what's all that top hamper then ?

Motu

4th June 2009, 22:55

My C50 clutch didn't work....the centrifugal bit.The ramps were worn,and it stuck on.So I rode it with the foot pedal for years....took off lifting my heal off the lever.There was only one intersection on the way to work (Waiheke Island),and seldom cars there anyway.The hill start from my drive in the mornings was a bit tricky though.I came to Auckland for a weekend on it once,so had to fix the clutch before I came to the big smoke.Just took a clutch from one of my spare engines.

The slickshift was fun....we retrofitted them to our pre units.A story from the past - we went to get a big feed of fish & chips on my mates T'bird,and on the way back found a Highway boy broken down....so we stopped to help,as you do,even if he was a bike thief.It was an electrical problem and we didn't have enough parts in our pockets to fix it - so I went down the road to the pad to get the goods.I got on the bike (with ape hangers),and my mate gave me the big pack of takeaways which I held to my chest with my left arm.Then I put it in gear and took off down the road.

Later,eating our chips,I was told of the reaction - H61....''did you see that?,he took off with using the clutch.....Mate....'did he? are you sure?'

About the forks - anything but teles can have heaps of play in the front end without problems....just another stupid thing about telescopic forks.A stepthough with a vague front end under brakes? Completely normal again - leading link with the backing plate on the link.The front will rise under braking,and it will feel vague alright! Try it in gravel,,,get it to lock up...terrible.But you get used to it,it will never kill you....but you will feel it's trying pretty hard.

xwhatsit

5th June 2009, 00:09

Heheh. The heel bit I can't wrap my head around yet.

Would be a much better bike on Waiheke. It's a great bike -- except for when you come to an intersection or traffic lights. Then you have to build all that momentum back up again. I thought the 250 was good to learn conservation of momentum but this is extreme.

Good to hear about the forks. The rising front gives me the shits... glad the brake is only a wee thing, I wouldn't want to get close to locking it. Rear brake is much more useful than the front (especially if you shift your arse 10cm backwards :laugh:) The twisting just looks horrible though. On the other hand, those South-East Asians seem to do just fine lugging around 4 people, 8 chickens and a sack of rice so I'll stop doubting the suspension :D

Konan

27th March 2010, 19:46

Hey there, great to see I am not the only one restoring these old girls. I have come to a small glitch though. I am rebuilding a 1981 c50 with a 6v electric system using contact breaker points. I have bored the barrel and adapted the head to suit a bigger piston coz the old piston was siezed solid. Since I rebuilt the engine I have no spark, I have quite low voltages at the generaotor and the input to the ignition coil. Is this normal? Does anybody know what it should be? any help would be great and much appreciated.