ATC 70 help needed

[3wheeledfanatic]

My atc 70 will only run on choke until last night. Now it will idle off choke then die if any gas is given. Here is a list of things i have checked.

timing
valve adjustment
gas
tank
air filter
point gap
also cleaned carb twice jets are clean

What could it be? everything I checked seems to be good. Any help would be appreciated.

[3wheeledfanatic]

compression is also good

[just ben]

there is a bit more to a carb than just the jets.My guess would be you have a blocked air passage somewhere in the carb.

[3wheeledfanatic]

I soaked it in carb cleaner for 24 hours then blew it out with air. Could my intake gasket be bad? I know the o ring on the carb side is good

[350xx]

Put a new plug in it to be safe. Light some paper on fire, with the engine running, blow the paper out, and hold it near the intake. The smoke will get sucked in if there are any leaks. Cigs work too of course. If you cleaned the carb correctly, and gapped and timed it correctly there are only a couple things it could be.
After you check for leaks, check the points' condition since they are probably old.

Sounds like carb to me.

[CRAZY70MAN]

As Ben said. I know it sounds like Hoosier Daddy a broken record. Did you remove idle jet and main jet and us a small wire from a wire brush to clean the idle jet? Use aur compressor to blow out all the air passages as well. The 70 carbs are very touchy with dirt. Sounds like a blocked idle jet to me?? Good luck.

[Blown 331]

I know this sounds kind of odd and you said you already checked it but I've seen the same thing happen from too narrow of point gap. If it were me I'd open them as far as I could before it will no longer start and try that.

[Mosh]

Start the trike and let it idle till warm(Not scalding hot) but warmed up.. Then shut it off.

Turn your petcock off.

On the petcock side of the carb, at the slide area you will either have a brass peg sticking out, or a naked hole bored into the throttle housing near the idle screw. If it is a naked hole put your finger over it to block it. If you have the brass peg use 2 fingers to pinch around it and seal it off.

Next grab the overflow line down by the stator..with the hole blocked off with your fingers like ^^above^^ on the side of the carb, blow into the over flow hose as hard as you can (with your mouth) till you see gas run out the air filter housing. It will be hard at first, and as you start to see fuel you will feel the restriction go away in the hose.

Turn the petcock back on and hold the throttle wide open and start it with no choke......and rev the snot out of it till it clears up. Usually that will get any dirt out of your pilot and air passages. You may have to do it a few times till it clears up completely. It works if the carb is clogged. I have to do it on my stock 70's every few times I ride them.It sure beats tearing the carb off and cleaning them all the time..Make sure you run inline filters to help keep dirt out too.
Also stock 70's love new plugs every few months..They make a big difference in how they run.

Sandpupi showed me that trick at TF..

[3wheeledfanatic]

Well I tried everything above and it ran great for a shot time. i then readjusted points to .014 and another new plug then ran great again now it wont start at all. Checked for air leaks...none found. Could the flywheel be dirty on the inside? these little 70s are tricky.

[81Rmachine]

Still sounds like a fuel problem. How clean is your tank? I know when I first got mine the tank was pretty crusty inside and no matter what I did it would run for a bit and then act up cause I kept having rust plugging the jets or getting stuck right in the outlets on the bottom of the tank. I powerwashed it out, and was careful not to make holes, and havent had a problem since. Of course your tank could be nice and shiny just a thought.

[briano]

Try running it with the gas cap loose, maybe the vent on the cap is bad.