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That DT400
Posted by Andy C on July 10, 2022, 11:25 am
I eventually decided to fit a 12v conversion to it along with upgraded ignition.
The original CDI is known to cause problems usually when hot, the 6v electrics are not the best in the world hence decided on the conversion.
Easy to do, should be money well spent as I plan on keeping this bike for sometime.
I spent ages trying to track down a "fault" with the headlamp, just could not get it to work then I realised..........it only works when the engine is running - just call me Richard.
I have also fitted a nice high intensity LED lamp at the front - same as the one I fitted to the H2.
Anyway with the upgrade fitted it starts 2nd kick from cold, 1st kick when hot, no sign of any kickbacks - all looking good so far.
Just waiting for DVLA to come back with a Reg No, all there is left to do is fit new brake shoes (dont trust the bonding on 40 year old shoes), and fit some new tyres and tubes. Who needs a signature anyway......
Re: That DT400
Posted by geoff the bonnie on July 10, 2022, 12:58 pm, in reply to "That DT400"
Soon be a runner then Andy. Well sorted out now then.
Re: That DT400
Posted by Lannis on July 10, 2022, 2:08 pm, in reply to "That DT400"
Interesting side note that we generally consider 6V systems inferior to 12V.
Is this just because 6V systems are all very old, and they are having to fight old, oxidized connections, and having to push twice the current through (v. a 12V system) to get the job done?
I can't think of any reason why a 6V system WITH CLEAN PROPER CONNECTIONS should be "worse" than a 12V system.
Matter of fact, wouldn't that imply that a military-style 24V or 28V system would be even better for a bike?
Enquiring minds want to know.
Good on yer, getting that old nail back on the road. Sounds like fun.
LannisAt no time in history have the people forcing other people into compliance been the good guys.
Re: That DT400
Posted by Stuart on July 10, 2022, 3:59 pm, in reply to "Re: That DT400"
Hi Lannis,
>Interesting side note that we generally consider 6V systems inferior to 12V. >Is this just because 6V systems are all very old, and they are having to fight old, oxidized connections, and having to push twice the current through (v. a 12V system) to get the job done?
Can't speak for all old vehicles but certainly Lucas supplied British bike makers with many lower-Amps/Watts components for 6V systems. When Zeners first became available for charge control, not only could wiring be simpler, operation was too, they were 12V; certainly Lucas supplied more-powerful components rather than cutting the Amps consumed.
>I can't think of any reason why a 6V system WITH CLEAN PROPER CONNECTIONS should be "worse" than a 12V system.
In theory; you'll be aware of "Semper Gumby" and his bikes on BritBike.
However, in practice, the average vehicle owner is a lazy git - vehicle makers and repairers will tell you it's hard enough getting owners to maintain the bits that can be seen - electricity can't be seen so why would they want to pay to maintain it when it doesn't go wrong? 6V is simply a lower potential difference than 12V, so more likely to stop working sooner.
>Matter of fact, wouldn't that imply that a military-style 24V or 28V system would be even better for a bike?
Yes, but it requires better insulation. Rightly or wrongly, even if not governed by the first commercially-available Zener diodes, the automotive industry chose 12V.
Hth.
Regards,
Re: That DT400
Posted by Andy C on July 11, 2022, 9:17 am, in reply to "Re: That DT400"
I am sure that the 6V / 12V argument could go on and on, as both have their different merrits / pitfalls.
Main reason for converting the DT was that the CDI source coil was badly corroded and would be just a matter of time before it failed, also the OE CDI unit on the DTs have a reputation for unreliability and not being very co operative when the engine is hot.
I could have just bought the ignition upgrade, but it made sense to me to buy the combined ignition upgrade and 12v conversion - the coil that provides the power to lights and battery was also in poor shape.
The 6V system on the DT 400 also has a rep for blowing bulbs as it is poorly regulated, apparently Yamaha had many attempts at trying to sort it out, the 12v conversion I have is supposed to be better regulated.
One of the + sides of 12 volts is that I can also connect a USB adaptor to it - never seen one that works off 6 volts. It also means I can keep the battery topped up over the winter as I dont have a decent 6 volt battery charger, only 12 volts.
As part of the upgrade I also disconnected / re connected / cleaned every connector I could access, as well as adding the "star" earth point, so hopefully covered all bases.
The lights certainly look nice and bright !!Who needs a signature anyway......
Re: That DT400
Posted by Stuart on July 10, 2022, 3:42 pm, in reply to "That DT400"
Hi Andy,
One other thing you might want to consider adding is an earth wire from battery -ve with connections to all the components with electrics in/on them (latter e.g. the engine), rather than the electrics relying for one half of each circuit on random bits of bike with corrosion, paint and/or dirt in between?
Regards,
Re: That DT400
Posted by Andy C on July 10, 2022, 7:30 pm, in reply to "Re: That DT400"
Sorted that, I have added a "star point" to the coil ground.
The regulator is grounded there along wih the coil, I have extended the ground wire that grounded the old regulator to the frame along with the battery and connected them to the "star point"Who needs a signature anyway......
on July 10, 2022, 11:25 am
