I got a 70! I need some help...

[Louis Mielke]

Ok so I got this 70. $300.

http://i106.photobucket.com/albums/m254/louis_mielke/IMG_9367.jpg

It runs ok, but after I've ridden it for awhile it just kinda dies. I would kinda associate it with getting the engine warmed up. 15mins of ridding and it kinda just blubers to a stop. if I wait a minute and pull the rope it starts back up if I feather the throttle. I'm not real good with points engines. Any 70 gurus know what my problem is? I'm kinda thinking the points need to be gapped but I haven't taken the side cover off yet.

[TravEX]

I have messed with mine on and off for a few monthes and finally got it going good.

Check the carb/airbox boot to make sure it's ok.
Yes, check the points gap, at TDC should be about .012", adjust that. Check the valves and adjust them, .002". I rebuilt the carb and ditched the airbox for a clamp on filter from Dr ATV, and bumped the main to a 60.

That should get it!

You probably already know this, but www.dratv.com rocks for parts!

Good luck,

Travis

[TravEX]

O, btw, on the points, take the recoil off and the cage, and the points can be viewed on the left cut-out of the rotor when the timing mark is TDC. Above the points and to the left is a phillips screw, slightly loosen it, and then stick a flat head screwdriver into the adjustment slot by that screw to adjust the plug gap. On the 70's the points gap is the timing adjustment also. You can check the timing with a home-made timing light, but .012" at TDC should be close enough. Be sure the tighten back that phillips head screw so it doesn't come loose when riding.

[1upfront]

I had an 82 atc70 that did the same thing the bike was free and it had been under water me and my dad finally got it to run but it would only run for about 5 minutes before it quit so we pulled it apart and the rings were stuck in the piston and the blow by from it running would build pressure in the crankcase because the crankcase vent tube is only so big and the engine would slowly die out and a couple of minutes later it would start up again and do the same thing so we put new rings in the piston and honed the cylinder and it ran perfect.

[greenhuman]

Check the breather in the fuel tank cap. If its blocked a vacuum will form and not let the fuel flow fast enough or not at all. Try riding around with the cap loose and see if that fixes it.

[KASEY]

On the 70's the points gap is the timing adjustment also. You can check the timing with a home-made timing light, but .012" at TDC should be close enough.

just adjusting gap won't do it ,, there is an " F " mark on the flywheel ,thats where the points break,,, if the fiber on the points is worn you will not get proper timing ,,,,but i agree with the fuel tank vent theory,,,,,,,,,

[Dangerous-UK]

Check the fuel filter,it's behind the fuel tap on the carb 2 phillips screws(turn pet cock to off position first)