1976 Yamaha DT250C Project

[Darkrider]

So a specialist shop opened in town recently..all they sell is batteries and after a good chat with one of the reps that were helping get it all fully set up. They too suggested the same type of batteries as Weld suggested the SLA batteries for emergency lighting. Plus they informed me that they can be maintained with the smaller battery tender charger....so it def looks like i am going the way of the lightweight sealed lead acid battery. I will more then likely remove the ring terminals from the bikes wiring and opt for good quality bullet or spade connectors to use the new battery packs. Bonus point is the fact they are all of $20 each for a battery...i am going to do some measuring on the bike and see if i cant run two of them in the stock battery box...mostly for redundancy...have one go bad on me out on the road it is a simple matter of unplugging the bad battery then plugging in the back up.

[Weldangrind]

If you wired two 6V batteries in parallel, you wouldn't even need to unplug one. Just keep 'em both connected at all times.

[Darkrider]

Originally Posted by Weldangrind

If you wired two 6V batteries in parallel, you wouldn't even need to unplug one. Just keep 'em both connected at all times.

Hmmm good point....the packs are cheap enough its def worth looking into the idea.

[jct842]

You might check under the flywheel to see if there is room to add a small winding. It really doesn't take a lot to generate 6v ac and a simple rectifier to make it dc. even if you could only make low current it would extend the ride time with lights.

[Darkrider]

Originally Posted by jct842

You might check under the flywheel to see if there is room to add a small winding. It really doesn't take a lot to generate 6v ac and a simple rectifier to make it dc. even if you could only make low current it would extend the ride time with lights.

There were some ignition upgrades i seen on a Yamaha Enduro site i was reading awhile ago. The bike is actually wired as such that has a lighting coil and can run without the battery. Well at least run the Headlight anyway..the rest of the lights require the engine to be revving a bit to power them.

After reading through some of Spuds threads again recently its got me debating my plans for tires for this bike. It doesnt weigh all that much so it wouldnt shred tires as fast as say an XR so im open to suggestions for good tires that would be good for both pavement and dirt. The trials type tires on it currently arent too bad on pavement but they can get a bit squirrelly on the loose and sandy dirt around here.

[Darkrider]

Hmmm i see the pics i had in here do not work anymore. Something i will need to fix. Easy enough to do when i transport the bike to a friends place next week, Just take some new pics....hell i might even try to motivate myself to get out into the heat today to do that even...Anyways...Since i did mention this bike in my XL thread figured i would bump it up as well even if it is to put updated pics in.

Plans for this year with this bike:

Redo the battery wiring with good quality bullet connectors on the bike side and spades on the other side of a pair of adapter wires. That way if i do change back to a battery with ring terminals it is simple to swap over.

I may go looking for a wiring diagram for the DT to see where the fuses are..if there are any to be found. I may end up taking a trick out of how the Honda is wired up and placing an inline fuse between the bikes harness and the battery on the aforementioned adapters. Easy enough to do...just use an inline fuse holder for the positive wire.

Measure and see if i can in fact run two of the smaller SLAs in the battery tray for increased capacity.

Add a lead for battery tender with spade terminals on it for the batteries. Most likely will end up setting this up in a simple way. Namely just have the wires there to unplug the battery from the bike and onto the tender harness..that way it ensures that the bike does not drain the batteries from sitting with a light on or anything like that.


Weld since i know you are big into Mikunis do you know of anything in their line up (and or the clone line up) that is 28 mm? Was looking at the VM26 clones then found out the DT uses a 28 mm carb..not sure if going down to the 26 would cause me any issues or not.

[Weldangrind]

Good plan on two six volt gel cells; you could adapt a charging harness, so the two batteries are in series when charging or in parallel when in use on the bike. That means you only need a 12v Battery Tender.


I haven't researched a Mikuni for two-smoke use. They are different animals, since the pilot mixture screw usually meters air, not fuel. What's wrong with the stock carb?

[Darkrider]

Originally Posted by Weldangrind

Good plan on two six volt gel cells; you could adapt a charging harness, so the two batteries are in series when charging or in parallel when in use on the bike. That means you only need a 12v Battery Tender.


I haven't researched a Mikuni for two-smoke use. They are different animals, since the pilot mixture screw usually meters air, not fuel. What's wrong with the stock carb?

Hmm good idea on the charging harness, as for the carb, nothing really i was just wondering if there was an easier to tune upgrade out there.

[Darkrider]

Snapped a pic of the bike before making the trip to transport it to storage for awhile. I will be working on my Honda XL for the next while then i will get back to this bike since it needs very little to be running again.

[Darkrider]

Well i have some good and bad news....Good being the bike is coming out of storage on the 12th...bad being its going straight to a shop as i do not have much time lately nor the work space to get to doing the carb. So it will be going to the local Yamaha dealer to get the carb done along with the front fork seals.

[cheesy]

Sometimes you got to bite the bullet and have someone else do it.

[Weldangrind]

At least you'll be able to capture some of the riding season.

[Darkrider]

Originally Posted by cheesy

Sometimes you got to bite the bullet and have someone else do it.

Yup...i realized it was beyond me once the fork seals came into play. I may start looking for an old Yamaha XS650 roller to rob the forks from to gain a disk brake front end...I loose a bit of front height as the XS forks are an inch shorter..but i can regain that by going to a slightly longer rear shock and giving the bike a Super Moto type stance.

Originally Posted by Weldangrind

At least you'll be able to capture some of the riding season.

Yup this is true.

[Ariel Red Hunter]

Originally Posted by Darkrider

Hmm good idea on the charging harness, as for the carb, nothing really i was just wondering if there was an easier to tune upgrade out there.

Mikuni makes both 4 stroke and 2 stroke variations on their carburetors.

[Darkrider]

Well after months of waiting and dealing with other things...the bike is home and in the shed. Hopefully within the next month or so i can start working on it. need to order a new intake for it for sure if i can locate one. The existing one is cracked where it is molded to the metal flange that bolts to the head.