Karas288 Posted March 9, 2015 Share Posted March 9, 2015 hey guys I've got a technical question for you my DT 125 LC mk1 1982 which I recently purchased has a 6v battery which I'm thinking of replacing since not only does it need a new one but I wish to run a digital ignition (keyless) system and alarm that requires 12v I dont want to have to add a secondary battery I'd like to replace the current one with a 12v battery instead since unlike sport bikes theres not much room to hide things. The bike is currently being restored by myself and my father with occasion help from a mechanic so project "difficulty" doesn't really matter as long as its possible I'm thinking of changing the speedo to something more modern like a digital one from a YZF R125 or XT 125 later on too. Here are my questions for you guys. Can I replace the battery with a 12v one with or without replacing parts/modifying etc?. The service manual I have says that the lights and horn run off of 12v not 6v why then does it require a 6v battery? Just to add I have already connected a 12v power source and the neutral light, the oil light and horn function correctly I am currently unable to test the indicators due to a previous owner making a mess of the wires and even changing the power cables (no inline fuse as far as I can tell) oh and I am currently unable to start the engine since the bike is sat in my living room till next week hence my eagerness to sort out the electrics before the stripdown and powder coat etc. Any ideas or thoughts on this matter would be greatly appreciated. Many thanks. Karas288 Link to comment Share on other sites More sharing options...
slice Posted March 9, 2015 Share Posted March 9, 2015 Try reading this mate. http://www.waterlooville-mcc.co.uk/6vor12v.html It might help you decide if you want to go ahead with the conversion. Link to comment Share on other sites More sharing options...
Karas288 Posted March 10, 2015 Author Share Posted March 10, 2015 Thanks man interesting read so basicaly it is possible then just a bit of work and a few parts required I still dont know if its coil is running 6v or 12v but no worries I will bring out my multimeter when shes in the garage and do any mods if and as neccessary I will keep you updated when I get it done thank you slice. Link to comment Share on other sites More sharing options...
slice Posted March 10, 2015 Share Posted March 10, 2015 No Probs mate as long as it was of use to you. Yes get the multimeter out and see what it puts out if it's over 12volts direct then you should be golden on not having to change it. Link to comment Share on other sites More sharing options...
KevtheRev Posted March 13, 2015 Share Posted March 13, 2015 You'll have to change your reg/rec , relays and bulbs . Will the generator handle a 12v battery ? I'd leave well enough alone buddy . There are nice digital speedos for bicycles which work well and need no connection to the bike's battery . Link to comment Share on other sites More sharing options...
KevtheRev Posted March 13, 2015 Share Posted March 13, 2015 The HT coil would be the least of your worries as most will run at 6 or 12 v but the ECU and any other sensitive components may not . PS I'm no electrician but I'm sure anyone with more knowledge will tell you the same . I often had the same idea as you when using a 6v bike , crap lights etc but I think it's more trouble than it's worth . Unless of course you know an auto sparks who knows better than me . Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted March 13, 2015 Moderator Share Posted March 13, 2015 Have a look here for ideas Link to comment Share on other sites More sharing options...
KevtheRev Posted March 13, 2015 Share Posted March 13, 2015 Try reading this mate. http://www.waterlooville-mcc.co.uk/6vor12v.html It might help you decide if you want to go ahead with the conversion. Just don't forget , old bikes ran on points ignition , new bikes don't . Nothing wrong with points by the way . Link to comment Share on other sites More sharing options...
Karas288 Posted March 14, 2015 Author Share Posted March 14, 2015 Thanks for all the replies guys and for some very interesting reading. Just in case you were wondering acording to the manual my bike uses a CDI unit so I will have to make sure it can handle 12v before doing anything to it. One of the things I'm thinking of doing is replacing the wiring loom its 33 year old and is a bit of a mess I know to some people it might seem like a boring, difficult and useless task but I dont plan selling this bike anytime soon if ever and its going to a while before its road worthy anyway also I like electronics I'm a bit of a electronic hobbyist so its not like I dont know what I'm doing (for the most part anyway) but I've never done anything on this scale without prior knowledge and research and thanks to all your help so far I've already learnt some things I wouldn't have considered looking into (not before blowing up a CDI or two). I've put a XL 125 R 1986 on the road but that only required a few small bits and that was around 9 years ago. Thank you all for your help thus far . I'm going to look into the CDI, rectifier and other parts already on the bike and then do some more research into the project before going any further I will be sure to update this post with my progress when and as it progresses. Oh and I havent actually checked the bulbs since they weren't connected in the first place and the indicators are small sh*tty aftermarket one's like I say I'm going to leave it for now and I'm going to check EVERYTHING with a multimeter once its had a respray etc I hope you look forward to the results. Might not be for a few weeks yet since my dad bought a XT 125 recently and that should be ready for the road next week (MOT permiting). Might be out and about relearning how to ride (safely) since I haven't been riding since before I broke my ankle 3 years back. Link to comment Share on other sites More sharing options...
Karas288 Posted March 17, 2015 Author Share Posted March 17, 2015 Quick update Idling while cold the bike puts 1.5v across the battery terminals without the battery connected and after about 20 seconds run time the battery (whilst connected) charged from 2.3v to 2.5v thought this might be interesting to some. Also I've noticed it looks as though someones replaced some of the wiring loom with 240v house wiring so I'm definitely going to rewire the system top to bottom the petrol tank doesn't even sit correctly because the wires are in the way. Anyone had any luck with soldering the connector at the end of the clutch cable? I ordered a new clutch cable from M&P's in Gorseinon and they sent one that although it looks the same as the old one the inner wire is too long and wont actually disengage the clutch no matter how much I adjust it but it does have a adjustable connecting piece at the end which I believe is suppose to be soldered in place. My grandfather once soldered a clutch cable like this for my old 250cc quad and it worked like a charm but sadly he has since passed and I cannot seem to get it to solder correctly any hints and tips or a referal to somewhere where I can purchase the correct length cable would very much appreciated please. Link to comment Share on other sites More sharing options...
blackhat250 Posted March 17, 2015 Share Posted March 17, 2015 Yeh, get a soldering bolt [ plug in type] . flux. and a roll of solder, That voltage is way too low, the rectifier must not be connected, it be a small two spade type under tank,, Your looking for 7.5Volts engine running,, Link to comment Share on other sites More sharing options...
Karas288 Posted March 18, 2015 Author Share Posted March 18, 2015 Thanks Blackhat I thought maybe something somethimg wasn't connected this wiring harness is f**ked I think so I'm going rewire the system for now though I'm going to sort the hardware out (clutch cable etc) I've got an Iroda gas soldering iron and lots of solder I think it's a premix solder and flux can't remember the exact details but it's great for wires etc. I've managed to remember how my grandfather did it so I've snipped it down to size and bent the end so it holds in the connector but my soldering iron has run out of gas so need to get more I will let you know how it goes in a few days thanks for the help. Link to comment Share on other sites More sharing options...
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