ATC 70 trouble again

[42F67N]

I ordered a brand new carb for my 70 from beatrice atc i installed the carb without touching any of the adjustments the atc started 2nd pull with the choke open i warmed the 70 up tryed to turn the choke off and the engine died.

Fired it back up with the choke open and took it for a ride it was breaking up bad in first 2nd and 3rd gear but while riding it if u switched the choke to closed the bike ran perfect but if u stopped the engine died, but since it was a xmas present for my kid i let him ride it open choke for about a hour.

Today i got the manuel out and adjusted the carb to the specs listed in the book set the rpm by ear at approx 1500 rpm

The manuel says the pilot air screw should be turned 7/8 to 1 1/2 turns out when adjusted to these specs the bike wont start choke on or off, if pop started it wont even fire over. if i turn the pilot air screw out till its ready to fall out the bike will start sometimes but if u hit the gas it will bog and die,even slowly adjusting the pilot screw while running produces the same affect it bogs and dies.

[hondaATCman]

Are you making sure the screw is being turned a FULL one turn? I made that mistake by turning the screw out to what I thought was one full turn but it was actually half a turn and the bike wouldn't start at all. Let me know and we'll go from there.

[TimSr]

Even though the carb is new, Id pop the pilot jet out, and make sure its clear. It only takes a spec to plug it.

[42F67N]

I just checked the fuel choke to make sure it was clean even though its new there was nothing in it.

Checked for air leaks didnt have any i used all new gaskets.

i moved the needle clip up one to try to lean it out a bit still nothing.

Plug was black

Aagin i turned the mixture screw out to the point it was ready to fall out,and turned the idle all the way up bike started but soon as i tryed to adjust the carb to slow the idle down it died again.

[CHAD-98]

I think it is not getting enough air...

Pilot jet has to be clogged. Did you remove it? I would clean the fu@# outta that carb.

Do you still have the old carb? Try swapping jets.

Does the slide move freely? It sounds like something simple. Hope it is...

Dont give up,
Dave

[42F67N]

Tommrrow is another day lol ill mess with it again tommrrow

[jdparsons1]

Man,,, this is funny. The 70 i've been working on is doing the EXACT same thing.... I have taken the carb apart SEVERAL times and blown it out with both compressed air and carb cleaner. I get different results with different settings and it just will not run right. I didn't buy a brand new carb but this one looks brand new and i put a rebuild kit on it so all the jets are new and everything. There is absolutely no way that the pilot jet can be plugged. I got it to run decent yesterday but anytime i get on it it will bog down, then i lean down and put the choke on and it takes off but if i slow down it will spudder and die. seems to run better in 1st and get worse as you shift gears. I have rebuilt many carbs on the 90's and 110's and none of them have been a 1/8th of the pain in the ass this one has been.

[42F67N]

Atleast im not crazy lol ,i thought it was me ,this atc carb is about a big a pain in the azz as a woman.


I think it has something to do with the needle and the amount of slack in the assa cable if its got to much slack i think it makes the bike go rich cause my plug is dark black.

I manged to get it it running a few times for a split second i held the throttle wot and pulled it she fird up but bogged right down and shut off thats why i think its the cable adjustment.

[kdagenais]

Just for kicks try pulling your air filter and put the carb settings back to stock and see what happens.

[CHAD-98]

Just for kicks try pulling your air filter and put the carb settings back to stock and see what happens.

Good idea

[jdparsons1]

On mine i dont have the air filter on right now. I have noticed there is a small amount of slack in the cable.

[42F67N]

Illgive the air filter idea a try,could possable be it im using a yamaha blaster filter i cut to size because when i got the 70 the original filter looked like it was on fire lol.

[CHAD-98]

could possable be it im using a yamaha blaster filter
Dont think so.

Just thinking, if it needs more air, remove the whole airbox. That restricts airflow, and could supply more air. Just as a test...

[42F67N]

Coming soon 3 wheeler for trade haha :D