new project bike owner/ poster, need lots of help

[chris_avakian]

hey guys, so, i've been riding since i was a little kid, but with a big gap between my late teens, and now. mostly on honda 3, and 4 wheelers.
had a minitrail, and a 90cc stepthrough. not much real experience riding a real dirt bike or much, so i picked myself up this 70 dollar yamaha dt100, and im in big trouble here. the wireing is shot, headlight is gone, no battery, no coil, i dont know whats going on with this thing, i found a wiring diagram online, bu heard something that you can just strip the battery, lights, etc, and just get it to run basicly with no electronics at all.

other problems im having, are im not sure exactky what year it is, it needs a new carb which i belive i've found, its got a honda seat (lol), bit of rust in the gas tank, etc, etc, etc. your basic 70 dollar, should have gone to the salvage yard, but is just too cool to let it go, fixer upper project bike. im in a little over my head right now. i know my fist step should be to get a manual, but i dont have any idea where to start.
fall is here, and its together enough i should be able to get the new carb on, bypas most of the wiring, and get a few rides out of it befor i decide to go head long into restoring a 1970s yamaha.


any idea what forum i should be in? lol

thanks,

 

[chris_avakian]

so, i got spark, and took out most of the wiring i dont need. on to a carb, and some brakes.

 

[justalonewolf007]

Good luck! I think you are, for the most part, in the right forum. If you want, this could be put in the modifications etc forum, but not a scarey deal so far.

If you can, try post pictures of your progress! That would definitely hep us understand where you're going and what you're doing! (who doesn't like pictures anyways!)

 

[chris_avakian]

seems i lost spark. hmm... i found a wireing diagram, but im not sure its an exact match. the bike didnt come with the coil, so i had to use one off an old chinese scooter i have. think i need a new one... maybe a manual.

 

[chris_avakian]

tried posting a pic, but to no avail. i've taken the headlight/tail light off i've got everything all boxed up just in case i ever decide to put it back on the street, but i dont know. also, finally got the coil in, the carb, and got it all together, but havent really figured the oil tank out? i heard something like, i can just pre mix the gas, and it will work ok? i figure this will be a simpler way to go for now. this is the first 2 stroke i've worked on outside of a scooter, so im really just looking for any advice on how to run this thing befor i go blowing it up. lol

 

[chris_avakian]

got it sputtering, and it idles for about a few seconds, but dies. when you give it gas, it dies. im almost at a loss. spent all day racking my brain about this.

 

[Ol'89r]

Yes you can pre-mix your gas and eliminate the auto-lube.

If the bike won't idle, that is most likely a clogged pilot jet or pilot air passageway. The pilot jet is the little jet that sits next to the main jet. It will sit down in a hole and you will need a small flat blade screwdriver to remove it. Make sure you can see daylight through the center of the jet and all of the related passageways are clear.

On a bike that old, you may also have bad crankshaft seals. This will cause your bike not to run or idle right. Most likely the left side seal. You can usually replace that seal from the outside without splitting the engine cases.

Worn rings will also cause your bike to be hard to start and not idle.

 

[chris_avakian]

the carb is clean, the seals seem ok, so im gonna guess it may be the rings. this thing seems like its gonna be a money pit, but hey, i like the bike.

another problem is the oil in one of the front forks all just leaked out.

hmm.... :bang:

 

[chris_avakian]

so, i was going to take the whole head, and cylinder off the bike, and i noticed that the there was a ton of fluid in the lower part of the exaust. could that have been the reason? id try starting it, but in lue of tearing it down, finding the fluid, and putting it back together, the throttle cable snapped...

so, i need a new throttle cable. any recomendations for a new one? since im getting rid of the oil tank, and self mixing stuff, i can just use one single cable to go to the throttle, right? i dont need the one that goes into the engine?

sorry folks. lol. i must sound like a complete idiot here

 

[justalonewolf007]

Pictures would help - Create an account at Flickr or Photobucket, upload some pictures from your computer, then post the links that show up.

The fluid in the lower part of the exhaust...well...dump it out. This probably means that some water may have gotten in the engine. Which means that you'll probably need to rebuild it, or at crack things open and check it out. If water did get in the engine...well...it's not a good thing.

Fork seals aren't fun...

Go ahead and take the head and cylinder off...and check things out.

 

[2strokerfun]

Fork seals aren't fun...

But it's not a bad project at all on those old bikes. $10 and an hour and you'll have new seals.

 

[chris_avakian]

it was the little plug on the bottom of the fork that came out. i put it back in, just need to refill the fork now, and it should be ok.

i've got it running now, sortof. i got all the gunk out, good spark, carb is spotless, but its just barely idling. i can give it gas, and nothing. since i've set it up for pre mixed gas, im guessing it might be the jets now?

dont know...

all the seals are good, rings are good, everything is clean out, but its just not running right now.

if you search the photo section there should be a couple pics i posted in there somewhere.

 

[chris_avakian]

ok... so its running... like a champ. turns out the previous owner messed with the wires coming out of the magneto, so the wire i thought i needed was the power to the electrical, i guess? and the wire i needed had been snipped....

also... all day, every time it starts up, its been running backwards.

imagine i'll figure it out, maybe something to do with the timing?

 

[chris_avakian]

blah!

 

[2strokesrock]

Dont get to discourged:) you will get it going.
I am anxous to here how it turns out.

 

[chris_avakian]

just finished replacing a gear that broke under the clutch due to it running backwards. put the head back on after getting the rest of the gunk out of the crank case. bout ready to put it back in the bike, and start from scratch with the timing. might report back tonight if all goes well.

 

[chris_avakian]

its still running backwards... any tips on timing an old yamaha like this with solid state ignition (with no points)