1971 Yamaha DT 250 E, help me restore!!!!!!

KROSOVA

Member
Jul 21, 2008
3
0
I had gotten this bike from a older guy who had it since 72. He maintained it very well it ran good for about 2 months after i got it for $500. One day was riding and it backfired and bogged down and i had to kick the hell outta it a few times it started, ran like ****, but got me back down the road to where my car was. It never started again. That was about 3 years ago. It sat in a shed collected some rust lost some parts now i want to restore it. It still has some compression which amazes me. I told that and the way it broke down to an old biker and he said it sounded like it slipped time since it backfired the way it did then started again. Im not the best bike mech but I know the basics and can follow directions very good. My first Q is how do i change timing? And is it a magneto with a flywheel or stator plater Or what? My second Q is what can i do about rust in the gas tank? SOMEONE PLEASE HELP ME I LOVED THIS OLD BIKE!!! :laugh:
 

esworp

Member
May 15, 2008
19
0
Timing is changed without removing the flywheel.. on the contact breaker assembly there is a notch for a flat screwdriver next to a phillips screw. The phillips screw loosens the contact breaker assembly, and the slot adjusts the gap and timing.

As for a rusty fuel tank, I would advise that you Kreme it. I've heard super things about that product.

No matter WHAT you do, you NEED a service manual from clymer's for this bike. A bike that old that has sat for that long will need a bit of work, none of it is hard with the manual. trust me on this one, I just breathed life into a dt250, myself.
 

stumanarama

Member
Aug 29, 2007
306
0
Did you ever check the spark plug? Timing doesn't usually just throw itself off. I'd check all the basics first:compression, fuel, spark. if you have those three things and still no life, then maybe it is timing.
 

KROSOVA

Member
Jul 21, 2008
3
0
stumanarama said:
Did you ever check the spark plug? Timing doesn't usually just throw itself off. I'd check all the basics first:compression, fuel, spark. if you have those three things and still no life, then maybe it is timing.
Well back when it happened i put a new spark plug in and it still never started. And it was getting fuel but it did lose some (not much) compression. Im not sure all the reasons that would cause loss of compression. My thought was that I blew a whole in the piston or fried the rings causing it to not get enough compression to start. Although im not sure if that would even happen like that. Thats why i came here. Thanks for the reply though!! :)
 

KROSOVA

Member
Jul 21, 2008
3
0
esworp said:
Timing is changed without removing the flywheel.. on the contact breaker assembly there is a notch for a flat screwdriver next to a phillips screw. The phillips screw loosens the contact breaker assembly, and the slot adjusts the gap and timing.

As for a rusty fuel tank, I would advise that you Kreme it. I've heard super things about that product.

No matter WHAT you do, you NEED a service manual from clymer's for this bike. A bike that old that has sat for that long will need a bit of work, none of it is hard with the manual. trust me on this one, I just breathed life into a dt250, myself.
Thanks!! I think im gonna try that Kreme in the gas tank. Im gonna just clean everything as best as possible and throw a new spark plug and some fresh gas in it and see if she starts. It does have what i think is enough compression. So hopefully it does since i dont have much money to put into at the moment and i dont have a good place to work on it. :( and i will look into that clymers manual. Im sure it will help!!! Thanks again!!!
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
Back fired and quit, timing jumped? Check the woodruff key that holds the flywheel in place. Should be able to take the nut and washer off and see if it is still aligned.
 
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