Honda CB125TDC project - coil problems...

[nowhere.elysium]

Well, yesterday, myself, the Mrs and my mate went all the way to Cheltenham to pick up baby monstrosity:
https://farm3.static.flickr.com/2257/3539245696_678f955806_b.jpg

It was advertised on eBay as being a runner, with the chain and sprocket cover missing. In that, it was (I suppose) accurate: although the only way it could've run is largely by accident.
When we'd paid for it, gotten it home, and were re-checking it over for what needs to be done to it, I noticed that the carbs weren't actually in contact with the airbox at all, and that fuel was weeping from the carbs out of where the airbox should've been connected.
Add to that the fact that plugs are covered in sooty filth, and the electrical system is, um, interesting, it looks like we've gotten ourselves a fun project.

The engine turns over, but because of the state of the plugs, it doesn't fire at the moment. The sump's a bit on the oily side at the moment, so there are definitely some fluids in there, but it's at the bottom end of the range, according to the dipstick.

Oh, and the battery's knackered, too.

We're thinking of stripping it right down to the frame and cleaning up and repainting everything, because this is a nice little bike, and with a bit of tidying up, could make a very respectable work hack and baby tourer (if we're feeling brave enough to go 125 touring). So far, it's definitely filling the role of first bike for the Mrs. Or at least it will be, once it's up and working. We've got a provisional timetable of a couple of months for this one, because we both work full time and can only really work on this at weekends and in the evenings.

Updates to follow soon.
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[TUG]

Do you mean engine side? as petrol shouldnt be leaking into your airbox anyway?
____________________
Haz ER-5, innit!

[nowhere.elysium]

Nope, I mean at the airbox end. Hence my comment: the only way it could've started is by accident.
At worst, I'll have to replace the carbs. I don't reckon I'll need to, though. I'm going to open them up either this evening or in the week and have a shufty, to see if they're redeemable.
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[Welshd1k]

[nowhere.elysium]

[TUG]

[nowhere.elysium]

It turns over: you can hear the pistons when the starter's going. It's just not firing, primarily (I'm assuming) because the plugs are shagged, and there's not a clean airflow.
The battery's not in the greatest condition, either, so that's partially to blame. I'm not majorly worried about hydraulic lock (yet).
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[TUG]

I shall be watching this project closely, when you track the problem let me know as its interesting me alot.

Loads of pictures toooo.
____________________
Haz ER-5, innit!

[nowhere.elysium]

Heh. Just got hold of a wiring loom and tail fairing off eBay. I'll test it for continuity and everything before installing it, but it's got to be better than the mess that's currently in there...
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[TUG]

[warped one]

Great bike to choose for a hack/tourer.

Before I took mine off the road it was still running, even though it had, :winces: Been running without any oil in it for about a month, on 1 cylinder for about 3 and needing a rebore for about 30000miles, even with all that abuse, it still started 1st time on the button.

Just started rebuilding mine slowly over the last month.

ANd not sure if you know, but the oilily bottom of you engine is the main seal in block, will cost about £50 to do at a garage.

Cheers

Warped
____________________
amnesia - Never in the history of usernames has one been more accurate. Warped indeed. You sir are a fecking oddball.

[Gazdaman]

Whip the float bowls off the carbs, bet the floats are gummed to the bottom. Clean that up and the float valves will seal and I bet the fuel stops flowing.

Looks a decent project.

Gaz

[davthegreat]

i like the minimulistic-ness of the bike (not brick indys, no fancy things on the handlebars ect)

if you dont mind me asking, how much did you pay for it

[nowhere.elysium]

Well, we paid the higher end of what it's worth, to be sure: £160 is a little on the pricey side for a bike in this nick. However, since we're determined to get an everyday runabout out of it, that's not so bad. There wasn't a huge amount of alternatives available when we got this one, either: we'd both been scouring eBay and autotrader for a while, and there wasn't much that appealed and that was easy for us to get to.
I have to admit that I pushed to get this one in particular, because the Honda baby twins aren't so common anymore, apart from the mini Varadero, of course.
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[nowhere.elysium]

Well, here's one of the plugs after a shedload of scrubbing, and it's still caked in crap.
https://farm3.static.flickr.com/2097/3539220600_f8a299af2b_b.jpg

New plug time, methinks.


Although it's not the worst wiring I've ever seen, it's still a bit on the ragged side. The new wiring loom should sort all this out, because there's continuity problems all over the place...
https://farm3.static.flickr.com/2093/3539201378_19f36601c7_b.jpg

Also, the rust there is indicative of the general state of the machine: there's some surface corrosion, but I don't think there's anything huge to have me waking up with the cold sweats at 3AM.
Closer view of the rust:

https://farm3.static.flickr.com/2008/3539220710_04ce809b3b_b.jpg

As you can see, it's at the 'vinegar plus scrubbing' sort of stage on most of the bike. I may have to use electrolysis, if it's much worse than that elsewhere.

The engine's a big surprise, actually: I don't know if it just got scrubbed up or what, but it looks (externally, at least) to be in good nick.
https://farm3.static.flickr.com/2118/3539201352_2a29f2526b_b.jpg
https://farm3.static.flickr.com/2118/3539180646_bc6c83b589_b.jpg

Sorry about the relatively poor image quality: I was pretty knackered when I took these, so I forgot basic rules, such as "Don't shoot against the light" and "Take the lens hood off when using the flash". The next round of photos will be better, I promise.

I'm going to take the carbs off tonight, when I get home. I've got to sort out the SORN details with the Mrs first, though, so once that's done, I'll get on with being covered in gunky petrol deposits.
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[nowhere.elysium]

Had another look at the bike today; I'm likely to take the carbs off in an hour or so, once I've had some dinner.

Anyways: it turns out that the bit that I was really concerned about is likely to just be muck, as opposed to corrosion. I don't know why, but I periodically suffer from total brainfarts, and have the most stupid thoughts. I was worried that the engine section around the front sprocket was rusting. The it occurred to me that it's most likely made from alloy anyway, so that's not rust. Problem solved. Hopefully. Even if it is rust, it's still only at a surface level.
Before you all mock me for being such a tard, bear in mind that I was mainly giving it a cursory examination, and I saw the colour of the area, thus causing myself aminor brown trouser episode. Once I'd thought about it, I stopped worrying. Here's the offending bit:
https://farm3.static.flickr.com/2320/3542587341_9da1883a80_b.jpg

Here, however, is the bit of the bike that is suffering from corrosion: the centrestand.
https://farm4.static.flickr.com/3352/3542587369_7aedd3b56c_b.jpg

Here's a wonderfully fecked bolt for my personal delectation, once I get a replacement sprocket cover:
https://farm3.static.flickr.com/2084/3542587359_7c42b7cc2e_b.jpg

It's not particularly clear in that photo, but basically, the bolt's lost it's head, and it looks like someone's tried gouging it out with a spoon. The exposed shaft of the bolt is now concave, and flush with the receiving thread. Tits. I don't have a screw extractor yet, unfortunately. I do, however, have a tap&die set, so I can coax the thread back into usefulness, once I remove the previous mess.

Does anyone know if the centrestand for this model is compatible with any other bike models? I'm thinking I'm going to need to replace the centrestand, given that one of the feet is knackered, too. It's pretty weird how the bike stands a bit on the piss...
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[davthegreat]

that sproket is in better condition than mine is

[Billing]

I'd imagine a cg one would fit, yours looks identical to mine, got it from david silver spares, drop them an email and they will be able to tell you if its compatible
____________________
'84 TS50X, '91 TZR125, '89 CBR400RR, '91 VFR400R NC30, '98 R1
"Hey copernicus! Why don't you navigate yourself to the back of the line with your feet and stand there with your shit."
BCF Eastern members map here ---> g.co/maps/2tm8b PM me to be added to it!

[nowhere.elysium]

Cheers BillingTZR - I'll give them a shout, and see what they can turn up for me.

davthegreat: I have to admit, it's in much better condition than I was expecting. The rear sprocket's about the same. I'm going to try soaking the chain in warm oil, to see if I can get it into a usable state: it's not particularly bad, so I'm hoping that with a little coaxing, it'll do.

:edit: - David Silver do an original one for £50. Sweet. I'm going to have to hold off until the end of the month, though, because I'm skinted.
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[owdamer]

That cb125 brings back so many memories. I started off riding one of those. I blew it up, rebult it then some bugger nicked it from outside my house. Think i've still got a haynes manual floating about somewhere.
The centre stand problem is common. Mine did the same & i've seen loads more just like it over the years. I fixed mine by just sticking a bigger diameter bolt in, about 5/8ths" if i remember rightly. (twas over 20 years ago!.
I've never known a bike so hard to put on the stand, once you get it past the halfway point it falls heavily back which causes the stand brackets to elongate. There was the option of a sidestand when the bikes were new, but i've only ever seen one.

[nowhere.elysium]

They do punish them a bit, don't they? I was pretty surprised when I first put it on the centrestand myself - it did all the normal 'having to use momentum to lever it' thing, and then ka-chunk - it rocked back a few inches further than expected...

Either way, it works for now. Ish. It's missing one of its feet, so it's an off-centre centrestand. Kind of says it all, really.

Still, I'm looking forward to starting the stripdown this weekend.
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[TUG]

[nowhere.elysium]

It's an old crack, but it's there, yes.
Ain't no way I'm parting with a tenner, though: I'm skinted from buying tools and bike bits this month...

I'm of the opinion that the previous owner(s) didn't want to maintain this bike all that well: I pulled the carbs off today, and discovered that the airboxes were totally empty. Of course, given that only one of them was actually in contact with a carb anyway is merely a technical detail...

I'm going to crack open the carbs in a few minutes, when there's enough space in my kitchen. Photos will follow.


:edit: - 'twas more than a few minutes, truth be told.
The carbs were fine. There was a bit of old fuel in there, and one of them had a clogged main jet, but it wasn't properly fecked, or anything.
Either way, they're sorted now, so they'll go back on the bike tomorrow or Saturday. I've got to sort out some kind of filter for the airbox. I think that there's some K&N block filters in the 'spares' box that came with it, so I'll have to have a root around in there.
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[djsalt]

Its good to see another old Honda twin being restored, I'm currently sorting out a Benly 125T ( CD125 T). Keep the updates coming! What's the engine code on yours, CD125TE?
Dave

[nowhere.elysium]

UPDATE!

Turns out that aside from the clogged jet, and the complete lack of air filtration, it's got a weak spark, so I'm going to test the coils in the morning.
Fortunately, I can get spares from wemoto, but I can't determine whether it's the right rating for a primary or secondary coil.
Any ideas?


:edit:
Yup, I checked the coils, and the secondary one's knackered. It's reading 9KOhms, when it should be 4.5KOhms. The primary one appears to be fine, though. Does anyone know if they're actually different, or if the different readings are caused by some trick of the wiring loom?
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project