russeleoin Posted April 24, 2009 Share Posted April 24, 2009 Hi All, I am hoping someone can help with some idea's on a problem I am having. My YB100 (6volt) has been running perfectly for a year now. Last week I noticed when I turned the key on, the neutral and oil lights dimmed quite quickly. When the bike was running all appeared well, but I dont ride too far so it was hard to tell. Thinking I had a poor earth, I have cleaned and proved all of them. The battery is now dead( well damned close, 2.4v) it was new 7 months ago and not a cheapie either. I connected my multimeter and see that upon revving the engine the voltage rises with the revs to around 7.5v so I believe the charging circutary is working. But the problem is getting worse, unless I speed up the idle, it will cut out and upon riding, it is back firing and only appears to be firing on every second stroke. It has no power. I left the battery disconnected and as it should, the charge rose slowly. I think the battery is good, but am running out of things to try. I checked all the wiring now, it is in very good nic, and the few joins in the wires, I have soldered and covered with heatshrink. I am left thinking that it could be the rectifier, resistor or worst case, the alternator. Any ideas would be fantastic as I have run out, but will need to get to work on Monday! Thanks and regards Russ Link to comment Share on other sites More sharing options...
YPVS TONE Posted April 25, 2009 Share Posted April 25, 2009 Silly question but is the battery topped up with distilled water up to the level mark on the side of the battery ?Also i wouldn't run the bike without the battery connected as you will probably have problems with bulbs blowing. If the neutral and oil lights get brighter when you start the bike i would say that the charging system is OK. Tony. Link to comment Share on other sites More sharing options...
russeleoin Posted April 25, 2009 Author Share Posted April 25, 2009 Silly question but is the battery topped up with distilled water up to the level mark on the side of the battery ?Also i wouldn't run the bike without the battery connected as you will probably have problems with bulbs blowing. If the neutral and oil lights get brighter when you start the bike i would say that the charging system is OK. Tony. When I first noticed the problem, the battery was low. I had some acid from when the battery was new, so I topped up with that. Is is possible that the battery is dead? Link to comment Share on other sites More sharing options...
fosdyke Posted April 25, 2009 Share Posted April 25, 2009 Silly question but is the battery topped up with distilled water up to the level mark on the side of the battery ?Also i wouldn't run the bike without the battery connected as you will probably have problems with bulbs blowing. If the neutral and oil lights get brighter when you start the bike i would say that the charging system is OK. Tony. Hi Sounds like the battery if everything works ok when the bike is running. Battery on YB100 is really only a backup - power comes from charging system for the electrical circuits, and the battery comes into play when the revs drop to keep some of the systems going. My experience of my YB has been that you will go through a battery every year - so don't spend too much on them. The best battery I have had so far was a cheapie which I had to fill with battery acid myself - the ones I got from the dealer were cr*p. Good earths are really important on these little 6v bikes so make sure that they are good on all the equipment. I have considered a 12v conversion but not sure it is worth the effort - especially as my current battery seems to be a good 'un. Let us know how you get on. Link to comment Share on other sites More sharing options...
russeleoin Posted April 25, 2009 Author Share Posted April 25, 2009 I have found the rectifier to be dead so I think that is the root cause. I am only hoping that replacing it will cure the battery charging problem and I dont have to replace the battery as well. Yambits have them so I will buy a couple as they are cheap and I dont intend to get rid of my YB. Thanks for your idea's. I will update on whether the rectifier cures my problem. Regards Russ Link to comment Share on other sites More sharing options...
russeleoin Posted April 29, 2009 Author Share Posted April 29, 2009 Okay, so I bought a couple of new rectifiers. Stuck one in and started the bike, ha, it started and I thought all was well. Seconds later the farting and spluttering started. Current symptoms are: 1.On kick-start unless the throttle is open wide it will not start but as soon as it does it revs well. 2. If I slowly return the throttle the bike will settle into an even idle for about a minute, then it will splutter and die. 3. The plug is wet and black which indicates a worn engine or ignition problem. I checked the gap it is fine, and the plug is only a few months old so I havent ordered a new one. 4. The points gap is fine, but the points are a bit worn(I have already ordered new ones+condenser+coil) 5. The battery is still dead but after a few minutes riding up and down the driveway it held it's charge better. Now the neutral and oil lights dim after about 30seconds( previously they would come on and dim almost immediately).(New Battery ordered) Can you think of anything I havent covered. I cant believe it is a worn engine as it was working perfectly one day then stuffing around the next. It still does 55 easily and I can get to 60 on a straight and a fair wind but I dont tend to ride hard as it is really to take me the 8 mile round trip to the station and back. I am not too fat! 82kg and I do look after the bike, it is garaged and cleaned after being in the rain. I am however getting pissed off as it has been off the road now for nearly a week, and she how must be obeyed niggles about driving me to the station in time for me to get to work!. Regards Russ Link to comment Share on other sites More sharing options...
Moderator Airhead Posted April 29, 2009 Moderator Share Posted April 29, 2009 I would fit the new conenser and do a compression test as the next steps Link to comment Share on other sites More sharing options...
russeleoin Posted April 29, 2009 Author Share Posted April 29, 2009 Is there an easy way to do a compression test, some way that does not require a special tool? I was scammed out of £1200 on ebay 2 weeks ago so spending any money at the moment is an issue. Thanks Russ Link to comment Share on other sites More sharing options...
Moderator Airhead Posted April 29, 2009 Moderator Share Posted April 29, 2009 its not very scientific but you could seal the plug hole with your thumb, you should be unable to stop the gas escaping, better still borrow a gauge, where are you? BTW do the test with open throttle Link to comment Share on other sites More sharing options...
russeleoin Posted April 29, 2009 Author Share Posted April 29, 2009 I am in Surrey(Charlwood- Gatwick). I have the rotor off and plug out at the moment so will have a quick check when I get home. I am hoping all my bits will arrive tomorrow and I can fit them on Friday as I am working from home then. I gave the windings a visual check last night and they look good, I will put a meter on them tonight and hope for the best. Link to comment Share on other sites More sharing options...
russeleoin Posted May 5, 2009 Author Share Posted May 5, 2009 The end of the saga. Well, all my bits arrived, battery, coil, points and condencer. All of which were replaced and guess what, the problem remained!. I couldnt believe it, I nearly cried. I measured circits and all sorts and still had a problem. The bike would start but would not run smoothly unless it was revving high. I checked everything I could, and the by accident, I pushed on the key while adjusting the idling and the bike cut out. A bit more fiddling the problem was proved, the key switch is faulty, it seems to be arching across to earth. The reason it happens at idle is, that is when there is a bit more vibration, if I held the key still it ran fine. Anyway, I needed the bike for work so rather than replace the switch as I would have had to wait for it to be delivered, I have wired in a small kill switch. So now I use the key switch for lights and the kill switch for engine!. Still I am happy as I was able to ride this morning problem free. Thanks for all the suggestions. Regards Russ Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 5, 2009 Moderator Share Posted May 5, 2009 That was a stroke of luck...good one... Link to comment Share on other sites More sharing options...
russeleoin Posted May 5, 2009 Author Share Posted May 5, 2009 Thought I would add a picture of the old girl. Link to comment Share on other sites More sharing options...
fosdyke Posted May 5, 2009 Share Posted May 5, 2009 Thought I would add a picture of the old girl. Glad you got the problem sorted - sometimes it just happens that way - number of real headscratchers I have had sorted by a moment of doing something apparantly'random'. AT least the points and condensor will be useful as you know that they are new, and the battery will come in handy when the other one gives out (which it will!) just keep it trickle charged if you are not using it and it will prolong its life. Nice looking bike BTW - Here's a couple of pics of mine... Link to comment Share on other sites More sharing options...
russeleoin Posted May 5, 2009 Author Share Posted May 5, 2009 Hi Fosdyke, nice bike. Looks like you love yours just like I love mine. What is the difference between the Classic and the Delux? This is the first problem I have had with it and to be fair it is a pretty minor problem, just a problematic diagnosis. I put the new battery in anyway. All the info I have read on the site points to batteries being consumables for these bikes, and they are not the most expensive so I guess it is worth it. Is that the original carrier you have. Mine came with the bike when I bought it, but is not genuine as it has been cut in a number of places. Regards Russ Link to comment Share on other sites More sharing options...
fosdyke Posted May 5, 2009 Share Posted May 5, 2009 Hi Fosdyke, nice bike. Looks like you love yours just like I love mine. What is the difference between the Classic and the Delux? Yeah - gets tucked up under its own blanket in the garage! Guess yours like mine is a 1989/90 vintage - you can tell if it is a later one by the pre-fix 2UO on the frame and engine numbers - these 'benefited' from the rubber indicator stalks, different decals, chrome forks and one or two other minor mods. My bike used to look like yours until some b******ds got hold of it and trash it - so I had to do a total rebuild - tank, panels seat etc etc which is why the paint work on the tank and panels is different - it's from the pre 2UO version - but they were a real steal on ebay at the time - have got a spare tank in original colour and design but it wasn't in as good nick so it joined the growing amount of spares I have for the bike! Is that the original carrier you have. Mine came with the bike when I bought it, but is not genuine as it has been cut in a number of places. I believe it is - was with the bike when I bought it and doesn't appear to have been tampered with. Will post the picks prior to the rebuild when I get them scanned! Link to comment Share on other sites More sharing options...
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