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xwhatsit
29th January 2007, 23:56
Hi, quick question.

I have a kick-start road bike. I want to get rid of the battery (don't ask me why). I know I can do this, technically. Is it difficult? Will it cause running problems at low revs?

Also, will I get grief in terms of the bike being road legal (lights etc)?

imdying
30th January 2007, 09:22
As you've guessed, it's a crap idea on a CB.

xwhatsit
30th January 2007, 10:40
Lol, crap idea, or not... I've seen plenty of pictures to give me the impression that technically on the CB250RS it won't make it run badly -- however do I need to be able to have lights or anything while the engine is not running? Will the police get the shits?

imdying
30th January 2007, 11:09
Lol, crap idea, or not... I've seen plenty of pictures to give me the impression that technically on the CB250RS it won't make it run badly -- however do I need to be able to have lights or anything while the engine is not running? Will the police get the shits?

How do you feel about being rear ended in the dark?

Ixion
30th January 2007, 11:21
This used to be pretty common back in the day. From memory what you need to do is wire a 1000mf capacitor across where the battery used to be.

That stops thing frying, and avoids misfire problems.

Without the capacitor , the bike may start and run , but you'll likely get all manner of strange misfires and flat spots. Caused by the "frequency" of the unsmoothed DC falling in and out of alignment with the ignition system demands, I think.

Flyingpony
30th January 2007, 11:23
From my experience with Honda's, they won't work with the battery removed/unplugged.

xwhatsit
30th January 2007, 13:08
How do you feel about being rear ended in the dark?

Why would I be on the road without the engine running?

But cheers, Ixion. I was thinking about a bloody great capacitor actually, in terms of just smoothing out the peaks, but I'm not really sure about auto electrics yet so I wasn't sure whether that was smart. A battery functions like a capacitor, really, anyway.

Main thing I'm concerned about is WOF and other legal requirements.

Grub
30th January 2007, 13:20
From this explanation , I would say that you will fry your electrics




A wee bit of theory :

A bike alternator , in the absence of anything else , will produce some very high voltages . 20 to 30 volts typically.

We only want about 13 and a bit to run things and charge the battery.

Normally the alternator current (after being turned into DC) is fed to the battery. The battery is a big "sink" that "absorbs" the current. To make sure that the battery doesn't get over charged, there is a voltage regulator. This "shunts off" any voltage once the battery is fully charged.

When you run without the battery , all the alternator current is directly fed through to the regulator. Do that for too long , and the regulator gives up the unequal struggle and dies. Now, the whole 30 odd volts is fed into the bikes electrical system. The CDI unit (and other stuff) that is designed to run at 12 volts is suddenly getting hit with 30 volts. So after a bit, it too dies.The DCI unit will usually be the first to go, since it is full of transistors and other delicate whizzy stuff. No CDI unit, no spark. Or feak and weeble ones. Bike, him no go.

(Purists will note that I've simplifed things abit. It's a bit more complex, but that's the general idea)

xwhatsit
30th January 2007, 13:31
From this explanation , I would say that you will fry your electrics

Hmm I'm not convinced. Call me stupid (which I am), but isn't that the point of the current sink (bloody big capacitor) that Ixion himself mentioned earlier?

Point is, I know it can be done technically -- I've seen plenty of café CB250RSs minus their battery. How I will accomplish this, I will find out further down the track, probably from those who have already done this conversion. Ixion's capacitor idea sounds like that's the way to do it. What I really want to find out is, is the bike going to be road legal like this?

Alternatively, instead of the cap, I'll just ask my lecturers what the best and most efficient method of sinking a big current is. You'd still need the cap for smoothing out the pulses, and making sure current is still available for spark when the alternator hasn't supplied it. I wouldn't mind replacing the regulator with a switch-mode step-down controller instead of the big inefficient heat-generating (and thus self-frying after extended cooking) linear regulator. But with a big enough current sink, cooking the regulator isn't on the cards. 1000mF is a fairly large value -- that's a 1 farad capacitor -- that should be able to take care of a fair bit of unwanted charge, you could probably do it with a cap a tenth of the size, but a bigger one doesn't hurt.

Motu
30th January 2007, 14:14
XR250's run without a battery,no reason why a CB 250RS can't.The battery is just a storage device,so a capacitor can handle that.You may need a battery for indicators,stop light and horn...remember,you can use a bulb horn legally.Worst case is the engine stalls when you brake with the lights on....but engine should be seperate from lighting anyway.Get an XR wiring diagram and check it out.

imdying
30th January 2007, 15:14
Why would I be on the road without the engine running?

Main thing I'm concerned about is WOF and other legal requirements.
You know how if your battery is weak, your lights dim when you're idling and brighten when you rev it? I'd hate to see you squashed flat at the lights because of a dim taillight. As far as the WOF goes, so long as your lights go you're fine... you would have to check the manual on the LTSA website as to whether they need to operate without the motor running though. You don't want a stalled motor to get you run over! Imagine if all that work on the motor went to waste due to being totalled!!

I guess we should mull over what you want to accomplish... a 1 farad cap would take a little reengineering and a little bit of room... maybe just using a physically smaller battery (perhaps of a better quality with similar CCA?) would suit what you're trying to achieve better?

You could always attach a battery somehow for warrants of course... maybe a combo approach? Maybe a small 12v power pack stashed somewhere to run the taillight for 5/10 minutes if the motor dies, and a cap for general running with the motor on?

imdying
30th January 2007, 15:15
Worst case is the engine stalls when you brake with the lights on.Wot he said :yes:

vifferman
30th January 2007, 15:32
It's doable.
I used to run my MT250 without a battery, because the headlight ran straight from one of the coils on the stator/magneto or whatever the hell it had. The only problem I had was that it used to blow the tail-light bulb because I didn't have a battery eliminator or capacitor.
I took everything off that wasn't essential, and the only thing I ran afoul of Mr Plod with was the regulations changed regarding mirrors. Blardy silly, because the mirrors were used to useless so even when it did have one on I didn't use it.

Ixion
30th January 2007, 15:33
There is no issue with WoF. Many older bikes (famously, the BSA Bantam) had no provision for a battery and none could be fitted. You are entitled to have the motor running for the WoF check (though you'll have to go somewhere where you can stay with the bike, trying to explain that to a typical tester could be hard). Rev the motor for light and indicator checks.

Indicators will be the trickiest, sometimes the pulsating voltage upsets them But I had a T500 running just fine without a battery,everything working. Horn can be a bit feak and weeble, but as mr Motu says, if the tester baulks, just fit a bulb horn , from your local bicycle shop. Quite legal. Mates had all sorts of other bikes running too. It works. BTW, pre 1978 you don't legally need indicators or stop lights.

Only downside is (obviously) you need a kickstarter. And you will blow bulbs rather more often.

EDIT 1000mf cap is about 1 inch diameter, about 1.5 inch long. Try the electronic surplus place at the top of Queen St.

xwhatsit
30th January 2007, 22:57
XR250's run without a battery,no reason why a CB 250RS can't.The battery is just a storage device,so a capacitor can handle that.You may need a battery for indicators,stop light and horn...remember,you can use a bulb horn legally.Worst case is the engine stalls when you brake with the lights on....but engine should be seperate from lighting anyway.Get an XR wiring diagram and check it out.

Mr Motu sir! You're a genius! Now why didn't I think of the XR250? Same engine, even!

@Imdying: I see your point now. I wasn't thinking about the engine stalling -- that is a situation that I'd be on the road and the engine running. That's a good point.

@Vifferman: Yeah I'd love to lose the mirrors too -- both the originals and the borrowed spare ones I'm borrowing from GiJoe1313 (he won't take them back yet, lol) you can't see shite; and the vibrations from the thumper tend to make them pretty blurry at most RPMs.

@Ixion: Ah, thank-you -- I wondered about older bikes, but then I thought they might have some exception, like the 1978 indicator thing you mentioned (EDIT: I'm not pre-'78, just a little bit later than that). A squeezy-bulb horn would be a crackup! I'm having retro-café thoughts but I'm not sure I'd go that far back in time unless I had to...

As a side note, I love that shop -- Surplustronics it's called. Every time I walk past it I have to go in there, and end up walking out with so much useless crap. I got a couple of $5 barcode scanners once... lots of cool bits to scavenge. For the electronically-uninitiated, that shop is like walking into a bike wreckers -- so much cool decrepit stuff you want to buy but don't really need, lol.

F5 Dave
31st January 2007, 17:01
I would expect the CB is 12V, the deluxe elecy start version was. The XR will be 6V & pathetically small wattage lights & sod all for indicators. the ignition system will be self exciting whereas the CB will require a battery or a capacitor to work. Old two strokes & dirtbikes won't run ignitions that require a battery.

Go ahead & try it but don't be surprised that the tiny capacitor will be sucked dry with the lights on or low revs to the extent that there are ignition issues.

Yes Lin regs are dirty, but SMPS get pretty expensive for dealing with the current you want & bulky & fragile for motorcycle use & why bother when you can just run a battery? Are you really that concerned about the weight?

xwhatsit
31st January 2007, 23:40
I would expect the CB is 12V, the deluxe elecy start version was. The XR will be 6V & pathetically small wattage lights & sod all for indicators. the ignition system will be self exciting whereas the CB will require a battery or a capacitor to work. Old two strokes & dirtbikes won't run ignitions that require a battery.

Go ahead & try it but don't be surprised that the tiny capacitor will be sucked dry with the lights on or low revs to the extent that there are ignition issues.

Yes Lin regs are dirty, but SMPS get pretty expensive for dealing with the current you want & bulky & fragile for motorcycle use & why bother when you can just run a battery? Are you really that concerned about the weight?

My reasons for running sans-batterie are stylistic. I want to café my bike -- part of the plan being to remove the battery and airbox and side covers, so there's just an empty space with a carb and pod filter under the seat. I think it looks cool. Others probably do not. Weight is not an issue yet as I scrape the pegs only rarely -- I'm not an experienced rider by any stretch of the imagination.

You might be right about the XR having 6V. In terms of the ignition being self exciting... I'm not sure quite what you mean, but the stator on my bike is a permanent magnet, rather than an electromagnet, so it doesn't need a power source in order to trigger the CDI.

In terms of the SMPS being bulky or fragile, I'm not so sure. You're looking at 30V-12V, admittedly with a high amount of current going through, but there's little SOIC-8 chips that will do that that cost maybe $2-5.

In terms of the bike not having enough juice to get around with all the shiny things switched on, you might be right there. In any case I want to give it a go. If it's infeasible, I'll just make up a little aluminium battery box. *sigh*. It just somehow seems unnecessary...

I put some pics of some ideas. In the flat-tracker there is a much nicer battery box. Note: all pictures are CB250RSs. Don't you think the last pic would look so much nicer without anything under the seat?

Ixion
1st February 2007, 05:09
I think this is the look you are after , though this is an SR500.

You are right, the classic cafe racer was a minimalist look. And, indeed, that was the genesis of the cafe racer. I remeber when the genre became popular, and one of the primary drivers was to lose weight , while still remaining (just) within the law. All unnecessary items were removed , mudguards were replaced with aluminium ones (and petrol tanks often also) .

The design yardstick was of course the Manx Norton or BSA Goldstar, and as they were magneto ignition the battery was very disposable

What?
1st February 2007, 05:33
Now that you have stated your reasoning...

Here's a couple of ideas that may see you have your cake and eat it:
1/ Make a battery box that looks like an oil tank (or find an old oil tank to turn into a battery box)
2/ Have a single seat with a fibreglass cowl behind it, battery housed within. Or maybe fit the battery under the hump on a GB type seat.

Eurodave
1st February 2007, 07:07
Guzzi cafe racers also look really good with their frame triangle empty, but of coarse Guzzis NEED a battery, so they usually get mounted under the swingarm pivot behind the gearbox....

imdying
1st February 2007, 09:15
2/ Have a single seat with a fibreglass cowl behind it, battery housed within. Or maybe fit the battery under the hump on a GB type seat.Yes yes yes, either of these ideas is great. If it were mine, I'd make a 'leather' hump on the new seat (because you need a new seat, the CB is uuuugly), but the hump would be hollow. Get a gel battery that you can lie on it's side and there will be more than enough room.

Eurodave
1st February 2007, 11:22
Have a single seat with a fibreglass cowl behind it, battery housed within. Or maybe fit the battery under the hump on a GB type seat.

I do a range of fibreglass cafe/racebike seats.... PM me & we can talk further if you like......

Ixion
1st February 2007, 11:39
I like the simple idea, no battery. Why have something that you don't really want.

If it runs OK (and I reckon it would, singles are usually pretty good battery-less, cos they only need a spark every other cycle), then go for it.

At worst it may be lousy at idle with lights on etc. But so, cafe racers never DID run well at low revs , or idle. They were always spitting back through the ruddy GP Amals, and spluttering , and falling off-cam and generally being a pain until they got on the mega. Then it was all worth it.

I reckon that a nice docile , idles nicely, etc cafe racer is a sort of hairdressers bike. Out of character. Might as well have an electric starter.

Clipons, rearsets, good tyres, shorty mega, and it could be a really nice bike. And maybe show up bigger ones in twisty enough roads.

imdying
1st February 2007, 11:45
The man makes a good point...

xwhatsit
1st February 2007, 12:00
Lol now you see my point of view, I should explain myself better next time :D.

Yep, it's mainly a stylistic thing, but like Ixion said, it's kind of a simplification process.

I'm definitely leaning towards the GB500 leather-hump single Jap style seat. I never thought that you could fit anything in the hump though. Also in terms of reducing the size of the battery -- ideally a move to a lithium-ion battery would work brilliantly but unfortunately that would mean a lot of extra charging circuitry. Will have to read up on my batteries and find an easily-chargeable compact 12V.

The oil-tank idea I like as well. Interesting idea on the Guzzi, Eurodave, I wouldn't have thought there'd be anywhere enough room there. Will have to take a look.

Lol, well Ixion, my bike (well at least when it was running before) fit many of the criteria you listed -- bitch to start, always having to blip the throttle to stop it stalling, crackling and popping on overrun due to air being sucked through the cracked head...

Yeah, I've been looking at the other parts bike in my garage, and trying various seating positions with bits of plywood. I think if I had a café seat and clipons, I'd probably need rearsets just to be comfortable, at almost dead on where the pillion pegs are. The gear linkage looks easy -- just a longer pushrod, but the brake looks a PITA. Will have to shorten the rod I think, and I'm worried about it being in the way of the kickstarter (oh well, more bump starting then :D).

Just rambling now.

Thanks for your thoughts.

Oh and I think I must have really good night-vision anyway, lol. I did my commute at 11pm home from Remmers to the Deep South (well, not really, just over the border) without a headlight, and didn't notice until I pulled up to my garage and couldn't see shit. Good thing I had a brakelight, no?

avgas
1st February 2007, 12:01
Never had a battery on the TS. And i rode that on/off road for about 6 years. Lights, indicators everything still worked as long as the motor ran. The guy laughed when i had to start the bike to do the wof though.

davereid
1st February 2007, 13:43
Dump the battery. Ixions onto it, put a decent size capacitor in and everything will run fine.

On a car alternator, or some large mo.bikes, the alternator relies on magnetisim created by externally excited windings. So the voltage regulator turns these windings off, when the voltage reaches 14 (ish) volts, to keep it all at acceptable voltages.

On little bikes, the alternator has fixed magnets. The faster the engine goes, the faster the alternator spins, the more juice it provides. To stop these going overvoltage, the regulator is just a big heat sink - it diverts some of the current into itself, creating heat and keeping the voltage down.

So, if you find the bike runs fine at idle, try it with the lights on. Still OK? then just leave the lights on - they will assist using up a few joules that the v-reg wont have to turn into heat, particularly at higher rpm.

But the key point is, the battery once fully charged will draw very little from the alternator. So, the regulator has to do all the work, and this applies even if the battery is there.

Another idea - build yourself an auxillary regulator - one that cuts in at say 13.8 volts and does some of the work for the main regulator. pm me if you need a design.

xwhatsit
1st February 2007, 13:59
Dump the battery. Ixions onto it, put a decent size capacitor in and everything will run fine.

On a car alternator, or some large mo.bikes, the alternator relies on magnetisim created by externally excited windings. So the voltage regulator turns these windings off, when the voltage reaches 14 (ish) volts, to keep it all at acceptable voltages.

On little bikes, the alternator has fixed magnets. The faster the engine goes, the faster the alternator spins, the more juice it provides. To stop these going overvoltage, the regulator is just a big heat sink - it diverts some of the current into itself, creating heat and keeping the voltage down.

So, if you find the bike runs fine at idle, try it with the lights on. Still OK? then just leave the lights on - they will assist using up a few joules that the v-reg wont have to turn into heat, particularly at higher rpm.

But the key point is, the battery once fully charged will draw very little from the alternator. So, the regulator has to do all the work, and this applies even if the battery is there.

Another idea - build yourself an auxillary regulator - one that cuts in at say 13.8 volts and does some of the work for the main regulator. pm me if you need a design.

Thanks for that info. Bike definitely has fixed magnets. The brutish-looking linear reg has a big enough heatsink on it to cool my old C64.

The lights-on idea sounds interesting to me. The cap wouldn't take long to get charged up, and then the reg would be copping it a fair bit. An auxiliary reg isn't a stupid idea either -- didn't think about a voltage low-pass on it to share the load. That's a very smart idea. I might ask you about the design of that at some stage; 90% of my knowledge is in digital circuits, and the other 10% on enough analogue stuff to make the digital stuff not fry.

I think what I might do once the engine is repaired, is to take my multimeter and just have a bit of a poke around at various RPMs to see what's going on.

Ixion
1st February 2007, 17:26
Um. I think I said a 1000mF capacitor. On reflexion, it may have been 1000 microfarad. Bit of a difference I know, but this was thirty years ago. I may still have one, I'll have a look round. Just that a one fard capacitor would be bigger, a lot bigger, than I recall.

xwhatsit
2nd February 2007, 00:04
Lol! I mentioned to a fellow Compsci that I was going to have to find a 1 farad capacitor and he just about shat his pants... he told me he wasn't going anywhere near it, and to wear oven mitts while shorting it out with a screwdriver, hahaha. Yes, 1000uF seems a bit more practical. But if it's bigger than what is required, it doesn't really matter. I'll just get the biggest one I can find and reasonably mount.

imdying
2nd February 2007, 08:06
Go to The Warehouse or Supercheap auto. They'll have some big caps for use in bling bling audio installs yo!

Ahem. You could even get one with a built in digital voltmeter :rofl:

Coyote
2nd February 2007, 08:16
I was running the RG without a battery. It wasn't working for some reason and since I could get away with kicking it I just left it.

The other day it broke down. Found out I burnt out the regulator and the CDI. Luckily I had the second bike to rape parts off to keep the first bike running for now, but I'll need to get a new regulator and CDI. WMCC said the last listed price of an RG150 CDI was $760. A RGV250 regulator is $100 on trademe. The bike in it's current state is only worth $1200.

This was all because I didn't know I needed a $2 fuse that's easily replaced. Just above the battery.

I don't suggest you run it without a battery.

rok-the-boat
15th February 2007, 21:46
My DR250 runs fine with no battery - it has done 68000km! It does have a capacitor though. And my DR500 (6v) runs fine with nothing but the CDI and coil, thouhg from what I have read here, I might just stick the voltage regulator back on.

And if you get some diodes, you can string them together and make a regulator. I made one - I think from Zenner diodes - can't remember exactly - for a DT175. Put 6 in line, wrapped them in ally foil, put it at the front in the wind, and it worked fine - never bust. (Not sure if they were zenners, I just bought what my electrical mate told me to and they worked just fine). Cost about $10, 15 years ago.

xwhatsit
15th February 2007, 23:14
My DR250 runs fine with no battery - it has done 68000km! It does have a capacitor though. And my DR500 (6v) runs fine with nothing but the CDI and coil, thouhg from what I have read here, I might just stick the voltage regulator back on.

And if you get some diodes, you can string them together and make a regulator. I made one - I think from Zenner diodes - can't remember exactly - for a DT175. Put 6 in line, wrapped them in ally foil, put it at the front in the wind, and it worked fine - never bust. (Not sure if they were zenners, I just bought what my electrical mate told me to and they worked just fine). Cost about $10, 15 years ago.

Using diodes like that, that's not really a voltage regulator, it just gives a voltage drop (any diode has a certain voltage drop). Wouldn't do it that way myself, would be worried about spikes and sags too much -- either too much electrickery, or not enough to keep everything ticking along.

I've got all the engine bits I need to put my mill back together, so we'll see if it runs first before I go fiddling with the electrics :D

davereid
16th February 2007, 09:14
Using diodes like that, that's not really a voltage regulator, it just gives a voltage drop (any diode has a certain voltage drop). :D

No, zener diodes arent used like that.

You buy a zener of the correct rating - say 14.2 volts, 75 watts. You place it across the circuit as a load, with its cathode to the circuit positive.

It will not conduct at all untill the voltage exceeds 14.2 volts, then it will start to conduct.

The internal resistance of the alternator means as you draw more power from it, its terminal voltage will drop.

So your zener diode will act very effectively as a voltage control device, effectively shunting away power and turning it to heat.

Cherap, easy, no moving parts, ideal for your project.

xwhatsit
16th February 2007, 12:27
No, zener diodes arent used like that.

You buy a zener of the correct rating - say 14.2 volts, 75 watts. You place it across the circuit as a load, with its cathode to the circuit positive.

It will not conduct at all untill the voltage exceeds 14.2 volts, then it will start to conduct.

The internal resistance of the alternator means as you draw more power from it, its terminal voltage will drop.

So your zener diode will act very effectively as a voltage control device, effectively shunting away power and turning it to heat.

Cherap, easy, no moving parts, ideal for your project.

Oh, ok, zener diodes. Should've read more. Why not just use a basic 78xx-style 3-pin reg when it's basically just a more heat efficient, accurate version? Probably just as cheap, too. There are plenty of variations of the 78xx series that let you deal with more current, and in those whopping great big transistor package types so you can stick a nice big heatsink to it.

Still want SMPS goodness, though :D

davereid
16th February 2007, 21:46
Yep, you could absolutely do that, and I'm sure it would work very well. Zeners were used on bikes since they were invented. Lots of old english bikes relied on them and they worked fine until that fast, high rpm daytime (lights off) trip home, when they would cook, and shortly after so would everything else.

xwhatsit
22nd June 2007, 22:10
Yay! So I dropped into Surplustronics a couple of times to see what they had in the way of large capacitors, but unfortunately (and surprisingly! I've never been disappointed in their range before, they have all kinds of weird stuff) they didn't have any huge capacitors available. I did buy a 15,000uF one, and half-heartedly tried to connect it up (don't think it would be big enough anyway), but the terminals were stuffed, and a screw sheared off, so I gave up with it.

However I looked on Trademe just recently and there's a guy called New Age Supplies or some such, selling a bunch of scavenged components. Amongst that lot he had a bunch of big capacitors! Got two, one 67,000uF 50V one, and a 56,000uF 30V one (40V surge). Was hoping that the 50V one would be the best option, however I'm not good with imperial measurements and it turned out to be physically massive in real life, so I tried the other one instead.

Worked perfectly! Held a surprisingly large amount of charge, too -- after starting it (it started first kick, although I'd already warmed up the bike) and hitting the killswitch, the dash lights stayed on for at least 5 or 6 seconds. Died pretty quickly with the lights turned on.

It appears to idle very well, although because the machine was already warm it idles more quickly than when cold first thing, so I'll be interested to see how it goes tomorrow morning. No strange missing down low, and combining the brake lights, headlights (low or high beam), indicators, and horn doesn't make it stall. The horn sounds piss weak though when idling with the headlights on, although it picks up when the revs do.

Slightly worried about the 30V limit, as nearly everything I read recommends 50V for some reason, but I'm pretty sure my regulator is still working well, so there's no reason it should go beyond 30V.

As I haven't got a pod filter sorted out yet, the airbox and battery box are still in place and I won't bother to try to mount the capacitor under the seat just yet. So it is currently primitively duct taped to the battery box arm and looks like complete arse. Covered the whole thing in black duct tape, so I won't zap my leg on it unawares, and also it looks less conspicuous than the bright electrolytic blue it was before (why are they nearly always that colour?).

Enclosed photo of it in all it's ugliness. My bike needs a wash, too! :innocent: The rain means it gets filthy in about four commutes. <hints id="hah_hints"></hints>

xwhatsit
23rd June 2007, 23:05
Next day, it's still working. Started easily enough on the kick this morning, just one kick and the neutral light was glowing (for a second or two). Rode all the way into the CBD and then to work, very happy.

Came home tonight in the pouring rain (where it had been sitting out while I was working), still worked very well, even with high beams on. No misses or farting about down low when idling with a panoply of lights going, the only time I had a problem was down low (at idling RPM) when I was applying some power, it died for a moment, but that could've been carburettion instead.

I'm quite chuffed. I need to work out a better mounting system, but won't bother with that until I get the pod filter sorted out. Woot.

xwhatsit
2nd July 2007, 21:31
Bitch. I've been quite ill for about a week, and haven't been able to ride it. So I fired it up today to go to work, all is well, happily idling, lights flicking on and off and brightly.

Anyway, get to the first corner, indicate left and the guy in front waves at me, he's pissed off because he thought I was going straight ahead. Not until a bit further down the road I realise it's my fault, my indicators are just on, not flashing.

When they're on, they're reasonably bright. It's just there just doesn't seem to be enough juice to make the flasher oscillate like it should.

Interestingly enough, everything works perfectly at idle, or low rpm, or, most confusingly, at moderate rpm but no throttle (i.e., at overrun slowing toward the traffic lights). WTF? With a handful of throttle and decent RPM, there doesn't seem to be very much juice, the lights get dimmer and horn doesn't work properly, indicators just stay on rather than flashing.

I'm hopeless with analogue electronics, I learned just enough to make my digital stuff latch and switch when it should, so I'm a bit confused here. At the moment my biggest idea is that the capacitor has lunched itself and is breaking down at high voltage/current. Feasible? However, the cap is rated for 30V, tomorrow I'm going to pull out the multimeter and check if my regulator has died (I have another, I think) and is giving more than that for some reason. This has only cropped up recently, before now everything was all systems go for at least 150kms. Perhaps rain has killed it.

I have the other (massive) capactor, 50V or somesuch. Bit of a pisser. At any rate the battery is going back in before I ride to work tomorrow, I didn't like having a possibly dim headlight, no horn, and having to hand-flash my indicators in the rain tonight.

On a possibly related note, my exhaust pops/crackle has all but disappeared at overrun. It was only when decelerating from 8,000RPM on the offramp that I heard a bit.

Deviant Esq
3rd July 2007, 00:02
Interesting thread mate, once again I'm impressed with just how much you're prepared to do yourself with that CB. Unfortunately I can't add anything constructive other than to say good on you and I hope you manage to get this latest hiccup sorted!

You mention earlier in this thread how totally ineffectual any mirrors at any RPMs are on your bike, due to being a thumper... as you know mine's a single as well, but unless I've got a lot of RPMs on the clock - like over 8500 - my mirrors are actually very effective. Around town I don't notice any vibrating at all, and even on the open road at ~105km/h (nearly 7000rpm) they're still pretty good. Guess maybe I'm lucky... it sure sounds like an authentic thumper! I'll take a little walk around video for you one day it's not pissing down if you like. :)

xwhatsit
3rd July 2007, 01:59
Interesting thread mate, once again I'm impressed with just how much you're prepared to do yourself with that CB. Unfortunately I can't add anything constructive other than to say good on you and I hope you manage to get this latest hiccup sorted!

You mention earlier in this thread how totally ineffectual any mirrors at any RPMs are on your bike, due to being a thumper... as you know mine's a single as well, but unless I've got a lot of RPMs on the clock - like over 8500 - my mirrors are actually very effective. Around town I don't notice any vibrating at all, and even on the open road at ~105km/h (nearly 7000rpm) they're still pretty good. Guess maybe I'm lucky... it sure sounds like an authentic thumper! I'll take a little walk around video for you one day it's not pissing down if you like. :)

<hints id="hah_hints"></hints>Hehehe cheers. I'm in love with the bike, I've ridden a surprisingly large number and variety of different bikes since I started riding, yet this is the bike that still has me itching to get in the saddle and twist the throttle. A GSXR600 was exciting, but I think I'd get sick of it relatively quickly, whereas this bike is still amusing me every day.

The original mirrors didn't vibrate much, they were perfect, and neither do GiJoe1313's Hornet mirrors (which I'll probably put on when I do my licence). However I'm using a single bar-end mirror, and with clipons and a poor mounting arrangement a lot of vibes do get transmitted from the engine to it. I think the vibes have got slightly worse since the beginning, there's a stupid little manual chain tensioner for the balancer shafts that you have to pull the sidecover off to do. Long-term CB250RS owners apparently really get the shits about this.

I'd like to see that vid :) That's one thing that does disappoint me about the CB, and that's that it sounds too damned quiet and meek. I can feel it thumping, but nobody else can lol.

xwhatsit
3rd July 2007, 15:24
Well, I got it sorted. Pissed about with my old battered multimeter for a good half an hour, testing at various RPMs -- my charging system and regulator all seem to be doing a very good job. Most odd.

Anyway, after using my brain I started to realise. The engine will always work perfectly, as the coil et al is connected to the generator through a completely different system than the lights. I know this, as once I knocked a terminal off the battery and the bike ran perfectly, except under a certain RPM it cut out, and none of the lights worked.

So then I realised, when accelerating, at decent RPMs, the bike vibrates. Under deceleration, despite highish RPMs there is much less vibes. The vibes seemed to be the source of the fading lights and voltage -- so I unwrapped the capacitor, and sure enough there was a loose terminal on the cap. So simple! Some clown in the bikes history has fitted two different sized terminals to the negative and positive leads, so I hunted around in my box of goodies until I found some washers which were able to pinch the terminal appropriately. Don't have any correct size terminals, will hunt some down.

My father told me `electrics are a bitch on cars and bikes, because vibration shakes all the solder joints loose'. Then again, I do remember him being crap at soldering.