JGreen27 Posted March 16, 2014 Share Posted March 16, 2014 My name is Jake and I am new to motorcycles. I own a farm and have worked on many tractors, chainsaws, dump truck, etc. but liquid cooled two strokes are new. Ok, so in laws have a scrap collecting business. Yesterday I was rummaging around and found what is left of a DT 125. I am not exactly sure of the year and info on finding that would be helpful. I got it out of the scrap heap and began looking it over. It is missing the seat, rear fender, and some other odds and ends like blinkers and tail light. Mechanically it seemed intact. I kicked on the kick lever and the engine rotated about 1/2 a revolution and stopped. I removed the spark plug to examine piston and cylinder with flash light and cylinder was full of water and oil. Could this be from laying on its side for 2+ years? Or is this a major problem? Anyway, got the rear tire freed up so it would roll and turn the engine over. After a couple major sprays of the watery oily mixture the engine freed up and turned just fine. I pushed the bike round for about 15 min until most of the oily substance stopped coming out. Then I removed the exhaust and more oily substance poured out. Needless to say I believe I have gotten most of the fluid out without removng any major mechanical parts like head or cylinder base. Out of pure curiosity ,and after I saw some spark from the spark plug, I poured just a little gas straight into the cylinder. After a few kicks it fired and somewhat ran for 3 or 4 seconds. I stopped working on it then because I am a newbie to motorcycles and wanted to ask some questions. Questions: 1. Everyone has said these bikes are a joy to work on, so does anyone think I can get it running good enough to ride about on the farm for lets say less than 500? (I would like it to move me and it under its own power.) 2. The compression seems low. I can kick it over easily with my hand, just by pushing on the kick lever. Does this scream new top end? If so, where can I find a complete top end kit? 3. Lastly, if this bike is worth some clean up and money, how much is too much? I don't want to drop 2500 or some high amount into something that is not worth it. 4. How do I find the year in the serial number? 5. Why was there oily fluid in the cylinder? Thanks ahead of time for your time and any information Jake Link to comment Share on other sites More sharing options...
Moderator Airhead Posted March 16, 2014 Moderator Share Posted March 16, 2014 Hi Jake, you say it's a water cooled bike, perhaps the fluid in the cylinder is coolant...maybe a head gasket leak? Anyway post all your questions and progress here in this thread so as to keep it all together rather than a new thread for every problem. Learn how to post pictures we would like to see it and posting the VIN # might help. As for how much you spend really depends on availability of parts in US...ebay...craigslist etc. Link to comment Share on other sites More sharing options...
dt502001 Posted March 16, 2014 Share Posted March 16, 2014 Hi and welcome to the club Jake Water colud have come from sitting on it's side,but worse is if the coolant system was left to freeze could have cracked the head/block. this you wont know untill you actualy get it running or pull it appart.But as it dose run and your not investing alot in it I would clean the carb up so it can run on it's own fill the rad and see what happens.Don't forget to mix some oil in the gas the auto lube system might not be working and you dont want to seize it for lack of lube Oh a 30:1 mix will be fine so your chain saw gas will be fine As for being able to kick it over by hand,,, well being a farmer I bet your pretty strong so dosen't mean much on a 125 with 8:1 compression,and it only makes about 14 hp. Pop a compression tester in and see what you have they will run with 60-70 no problem. A quick break down on cost of parts all approximate. new tires 70-100 each used from a local racer 40 a pair or free inner tubes 10 each new pistion 80-100 ( rings and wrist pin included wiseco). Bearing 15 gasket base 6-10 head 20-30 Crank seals 20 chain sprockets 100 wheel bearings 20-30,the numbers on the bearing tell you what they are and a bearing supplier will be cheaper than a bike shop. Ufo fender 20 but might not find a dt one and have to mod a yz fender. Seat that will be a chalenge a trip to a bike wrecker might turn up something useable,or ebay UK a lot more parts for the dt's there than this side.There are alot of dt 125's there and a few members are realy into them so they could probably help if you want the stock seat. The vin post it here and someone will crack it or call your local Yam dealer they can too,but it should be the 10'th. If you just want to fix it to run around the farm and not ride it on the street then you should be able to put it together for less than 6-700. The pipe would have had a build up of old oil and could have filled up with rain and filled the motor,but then the condition of crank bearings comes to question. You didnt mention where in the USA you are some states are better and easier to get parts.The amount you spend will be equal to how much you want to get it back to stock and how many parts you change. Link to comment Share on other sites More sharing options...
JGreen27 Posted March 16, 2014 Author Share Posted March 16, 2014 Thanks for the reply guys. I am going to work on it today and will hopefully be able to post some pictures. I am from Alabama and have a couple of Yamaha dealers here close so I will check with them about parts. Also, I have ordered some parts for fourwheelers from cheapcycleparts.net and they seem to be a reputable website to order from. Have any of you had any experience with them? I will try to do a compression test today and will tell results tonight. Thanks for the help gentlemen. Jake Link to comment Share on other sites More sharing options...
slice Posted March 16, 2014 Share Posted March 16, 2014 Jake if it's a 2 stroke and it's sick you will have people falling over themselves to help you out, for some reason there are a lot of guys on here who just love these old smokers, good find by the way, always nice to bring a bike back to life rather than turn it in to dog food cans. Link to comment Share on other sites More sharing options...
JGreen27 Posted March 16, 2014 Author Share Posted March 16, 2014 Ok guys after doing more research and looking closer at the bike I realized that I have made a big mistake. It is not a DT 125, instead it is a DT 50u. I am sorry for the misleading identification. That would explain why it is so easy to kick over. Now I go back to my original question, is it worth fixing since it is not a 125? All I will be using it for is checking on cows and moving around the farm. Will it pull me? I am 6'1" and 210lbs (95kg). Once again sorry about not knowing what I am talking about. Thanks Jake Link to comment Share on other sites More sharing options...
Moderator Airhead Posted March 16, 2014 Moderator Share Posted March 16, 2014 It'll pull you Jake but at 95 kilos it will struggle to catch the cows Look deeper in the pile for a 125 Link to comment Share on other sites More sharing options...
blackhat250 Posted March 16, 2014 Share Posted March 16, 2014 Pop up the frame number ,till we see what model it is,, its on the headstock, turn steering and read it , if its rusty , sand the area ,as numbers are stamped into frame,, Link to comment Share on other sites More sharing options...
JGreen27 Posted March 16, 2014 Author Share Posted March 16, 2014 Frame number:jya3bka04jc003500 Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
JGreen27 Posted March 16, 2014 Author Share Posted March 16, 2014 Ok good news checked the radiator and it was full of antifreeze so oily substance was not coolant. Also was able to get enough gas in it to let it run for 10 or 15 seconds and it ran great. Just took the float bowl off and it was filled with white crusty material. It is currently soaking in carb cleaner. Let me ask a question, it is a mukini and I can get a kit for around 30$ but I can also get a new carb (unsure of brand) for 30$ also. Which would be the best approach? Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Moderator Airhead Posted March 16, 2014 Moderator Share Posted March 16, 2014 Clean the original either ultrasonic of the best you can do with carb cleaner and compressed air...save your money if the carb is only dirty Link to comment Share on other sites More sharing options...
Moderator Cynic Posted March 16, 2014 Moderator Share Posted March 16, 2014 The kit, those new carbs for 30beer tokens are cheap nasty chineese copies and are truly awful. Link to comment Share on other sites More sharing options...
JGreen27 Posted March 16, 2014 Author Share Posted March 16, 2014 Ok thanks guys I will try my best just to clean it really well. Just found a good bit of rust in the tank. In the process of rolling ball bearing sized rocks around in it to free it up. Any other tips on cleaning it up? Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Moderator Airhead Posted March 16, 2014 Moderator Share Posted March 16, 2014 Thats a good way to do it jake, fishtank gravel Link to comment Share on other sites More sharing options...
JGreen27 Posted March 16, 2014 Author Share Posted March 16, 2014 Well we have done it before on tractor tanks and it seemed to work ok. Is there a better way? Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Moderator Airhead Posted March 16, 2014 Moderator Share Posted March 16, 2014 Remove the petck first in case there is a filter screen inside of the tank It's a good enough method Link to comment Share on other sites More sharing options...
JGreen27 Posted March 16, 2014 Author Share Posted March 16, 2014 Filter screen was inside got it out thank you sir. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
JGreen27 Posted March 17, 2014 Author Share Posted March 17, 2014 Ok gentlemen just called it quits for tonight. I was able to get the carb somewhat clean but it is not good enough. Throttle cable is broken so that's a problem. I was able to get some gas in the bowl and it was enough to actually ride it. I held the throttle about half. Ok so as usual I have some questions. 1. After running it a couple times I noticed lots of black oil in the exhaust. I immediately thought it was somehow pulling oil from the tranny. I pulled the cap and the oil in the tranny was white. Anyway why is there so much oil? Could it be bad rings? 2. If it is rings can I just put new rings on it and hone the cylinder or do I get piston and all? Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
dt502001 Posted March 17, 2014 Share Posted March 17, 2014 First check the rad level to see if it drops,if it does then the water pump seal is shot 5 bucks.White foamy tras fluid is normaly cause buy the WP seal,but as this has been sitting in a pile who knows drain flush with varsol and refill with clean oil,the amout is cast in case by fill hole something like 750cc =750mm =3/4 a liter =about a bit more than3/4 a quart LOL sorry my conversion is bad for imperial. The tranny and crank are seperate so unless the right crank seal is shot the motor cant pull tranny fluid. If you mixed your gas too rich then black smoke is normal,if the oil pump is working and adding even more then it will be way to rich. Wass there any oil left in the oil injection tank? is the oil tank even still on the bike? Hoses hooked up to anything? Link to comment Share on other sites More sharing options...
JGreen27 Posted March 17, 2014 Author Share Posted March 17, 2014 May be a couple mLs in the tank. That could be the reason. I teach high school science so metric is fine (better even). I thought it might be rich so that's a good thing. I will drain out the Coolant to check for droplets. Thanks for the info. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
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