1976 Yamaha DT250C Project
 

Heres a pic of the bike as it sits now. I bought it about 3 years ago as something to ride while i was working on my Honda Interceptor...Yea didnt plan on the Interceptor getting parked longer then originally planned lol...


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Parts installed so far:

MSR CR Mid height Handle bars
Renthal dual compound grips
Ken Sean carbon fiber mirrors

Parts still needed:

Battery (honda dealer sold me the wrong type and didnt even fill it)
Fork seals/Dust caps
Chain and sprockets
Kenda K270 tires
used rear shocks from ebay to run till i can have the Yamaha Thermaflow type shocks rebuilt.

This bike has been a hoot to ride over the past few years. I need to take the carb off at some point and clean it because the needle is sticking on it and it dumps fuel out of the overflow on the float bowl. Funny how i have the time to do this now finally but not the extra $$ to get any parts if needed lol

Note: these pics are a couple years old but the bike looks pretty much the same as of this time.

All any project takes is time and money. I usually have one, but not the other.

Thanks for starting the thread.

No problem, One thing i may end up doing with this bike is playing with the jets a bit when i do the carb to get a bit more 'snap' out of it. I am not sure what carb is on the bike at this time but i may seriously look at the idea of grabbing a mikuni at some stage if it doesnt already have one...plus i may look again at that idle mixture jet you linked to in my Gio thread if it will work on the existing carb..or if i can find a mikuni that can use that jet and that is compatible with this bike.

Indeed, thanks for starting this interesting thread. :)

No problem, once i get a free moment long enough to dig up as many early photos as i can of when i first got it...i will prob eventually start up a thread on my '85 Honda VF750F Interceptor as well. That bike is the one that has changed the most dramatically....When it was originally built in '85 it was a Red/White painted bike then sometime along the way it was in an accident and possibly repainted in the dark cherry color i found it in when i got it in '06 but at that stage it was still pretty much stock other then color. around '08 i had laid it down a couple times in a couple low speed incidents and thats when it went to a combination of satin and semi gloss black. between its cherry stage and its black stage it gained several modifications. But enough about that bike for now...it has its own story to tell later...;)


Back to the Yamaha this thread was started for...Its kind of a funny story how it was acquired....i had a near miss on the above aforementioned Interceptor due to water getting into the fuel and causing a high speed stall which in itself caused a nearly 10 km walk pushing a 540 lb motorcycle....anyways...While i had it in the shop and with it looking like it would be there for quite awhile i wanted to be able to still go riding. I was told of a Honda CB900F that was for sale and went and looked at it..That bike was a nice machine in need of a bit of wrench time that could be done on the fly. I saved up the cash for it along side the money to finish repairing the Interceptor. However i returned to the sellers house on the day i stated i would be back and the guy was no where to be found...Couldnt reach him or get in contact in any form...So i ended up doing a search on Kijiji (canadian version of craigslist basically) for bikes that were within my price range and that were street rideable. During this search i found this Yamaha on there and had remembered seeing and looking at this bike at a local dealership a couple years before. So i went to see if i was correct on it being the same bike i seen and i was correct. Took it for a test ride and bought it right on the spot soon after. I took the remaining cash that i had saved up for the CB and used it to get a replacement set of handlebars, grips and a replacement battery...however said battery was the incorrect type and wasnt filled at the honda dealer i bought it from even though thats how they did things normally..so the battery went back and the bike still has the battery it had when i first bought it. Im not quite sure how old the Dunlop Trials tires that are on the bike are...they are still in decent shape and barely show any signs of weather cracking so i will most likely run them for a bit longer if not outright build a second set of wheels and tires for the bike and keep the current assemblies as spares.

For excellent jet info, including dimensions, go to www.jetsrus.com

The battery in your Yamaha doesn't do much, other than provide storage for the charging system and help the signals and horn. You could certainly try a similar capacity in a gel cell, which is normally smaller and cheaper. A 12V5AH gel cell would likely do the trick, and they're often cheap at Princess. The nice by-product is that there is no vent, so acid doesn't drip on the frame.

Thanks for the link for the Jets, as for going Gel cell...i wish it was possible but the bike is 6 volt so im not sure if they even make one for that application.

Sure they do. I bought 6v4ah gel cell batteries for my Suzuki TS bikes. They worked great. I even bought a charger for it for cheap on eBay.

Now you have my attention!

I can't recall what I spent for 6v4ah batteries at a local electronics shop, but it was around $15 each. The charger was around $5, including shipping from China.

Sad part is there are no electronics shops here...So it could be interesting trying to source a Gel cell...But on another note do the gel cells charge fine on the TS? Charger im not too concerned about since i can always go with a Genius charger for that.

To the bike, it's just a lead acid battery. I had no trouble with it.

Do you ever get to Edmonton or Saskatoon? I'm sure you'd find one there. Just take measurements of your battery box first.

I very rarely go to either one. Last time i was in Edmonton was 2013 and the last time i was in Saskatoon was 2009, Nature of my jobs caused that...but now that im down to one job its a touch easier to consider taking that 2.5 hr drive lol

There's always mail order. I'll bet you could get one mailed from Active Components or someplace similar for cheap.

Stock 6N4B-2A-3
102*49*94 | Terminal position http://www.gs-battery.com.tw/images/...erminal-2w.gif = W17
This http://www.active123.com/BT6V5-6-Vol...-Prodview.html seems can be jammed in

You are def correct on this! Im sure with enough research i may find something that may work.

Hmmm you know..you may be right on that one...i will def need to yank the battery out of the bike and do some measuring! a SLA type battery is def a step in the right direction.

I think the battery that HB provided a link to is exactly what I used. YMMV.

It looks like a battery pack that would be used for emergency lighting and battery back up for alarm panels as well as for UBCs for computers. Those i know i can get here in town as i have seen them in many places before...Just never considered their use in motorcycles. It would only make sense it would work fine on a more basic bike like my DT since all it would be doing is powering the lighting.

This battery looks to be around the same size dimensions as the one HB posted its lower rated at 4AH but as Weld pointed out thats the size of battery he ran in his bikes...So...i may actually try this one first to see if it will work.

http://www.canadiantire.ca/en/pdp/6-...l#.VdUT831BkkQ

Why not? Price is right.

This is true...the only thing i do not like is changing from the larger ring terminals already on the bike to the spade terminals but eh....i may just make a jumper that has a ring terminal on one end and a spade on the other and bolt them to the existing wires then wrap them heavily with electrical tape...other option is replacing the ring terminals with decent quality spade terminals and making adapters that are the same as the jumpers i mentioned above...just reversed..

Could you use bullet connectors to be able to switch them out whenever you wanted? That way you have two leads each with either spade or ring terminals to use on whatever application you wanted. Not sure if that would work.

It could def be done that way, But then again if i use good quality spade connectors like ones from Grote with their heat shrink sleeves and the new ratcheting crimper i have i would only need one set of spare leads which would be the spade to ring terminal adapters. :tup:

Exactly what I did.

Nice! Good to know i was on the right track with this...Now i just gotta ask..can i charge these SLA batteries with a normal charger or will i need to look at getting a charger like you got from ebay Weld?

For the price, I just decided to grab the eBay charger and not risk battery damage. I presume that a smart charger would do, but I'm not sure.

Do you happen to have a link for one of the chargers you got? I may go that route just to play it safe as well but im not against the idea of getting one of the Genius chargers as well to try...if i cant charge the SLA with it..i can still use that unit on other vehicles like the Rat rod..i already have a Honda smart charger for the Interceptor.

What's the amp & volt output of that "normal" charger?
The older "dumb" charger often use linear power supply+ some "bridge ie. Charge voltage up & low as mains voltage changes …
This http://www.aliexpress.com/item/US-Pl...264347085.html is the newer "dumb". Steady volt output / current small enough to leave it charge overnight (won't boil it dry) ...

That's exactly what my charger looks like. Sorry, I don't have the link anymore.

This is the charger i was looking at...i actually had one here awhile ago for another project but ended up returning it because it turned out i didnt need it at the time.

http://www.geniuschargers.com/G1100

Ahh ok

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.

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.

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.

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.

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.

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.

http://i28.photobucket.com/albums/c2...wz24/DT250.jpg

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.