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View Full Version : Little idle issue with an ATC70, whats your opinion



lilatv
04-29-2008, 04:29 PM
Hello.

I have an atc70 Im trying to figure out for my nephews. I asked a simillar question a couple years ago and I followed the advice given then, didnt help this time, Im still puzzled.


Ill tell you what I know, you tell me what you think.


Its flippin cold here today 30.
I checked the valves/rockers, they are fine.
I have a strong spark.
Im getting fuel to the carb bowl, I took it off, dumped the old crap out, turned the fuel on, opened the overflow tube, gas ran out, besides that, it does operate fine as long as the throttle is engaged a little.


Whether the choke is on or off, it will start right up, without giving it any throttle 90% of the time. Whether the choke is on or off, it runs like a scalded dog, even with my ass on it.

Problem I was having was idle. At one point, it would idle with the choke on but slowly get to the point where it acted like it wanted to die, as you would expect, so I flip the choke off, it would rev up, then slowly get to the point it acted like it wanted to die, Id flip the choke on, it would rev up a little......see where Im going...teeter totter.

I messed with the only two adjustments on the carb, it made little difference. It finally decided to idle with the choke on but the second it went off, it would die.

Occasionally at idle, I heard what sounded like a quiet cough out the carb but it was sporadic and not in anyway constant.

I adjusted the idle screw all the way in and it didnt help it to remain idling with the choke off.


Is it just that cold nature? I puttered around for oh five minutes or so, thinking it just needed to warm up but it would at times act like it wanted to die unless I goosed the throttle a little. That was with the choke on or off.


I also checked the choke valve/butterly, inside the carb, it does open and close with the choke switch.



The muffled cough out the carb and the fact the choke needs to be on, makes me think lean, something i the carb, then again, it is cold today, dense air would cause it to want to be leaner, im just not sure that it would affect how it idles. All I can figure is I need to yank that little sucker off and either blow carb cleaner through the circuits or soak it....Im lost...I kept a record of the screw settings and they are where they were when it ran fine.


I know, long post but I wanted to be thorough. :)

TravEX
04-29-2008, 06:33 PM
Have you cleaned the carb good? Blown out the jets good? You could lower the clip on the needle one notch if you think that it's running a little lean. Also, richen the air screw 1/2 a turn or so, maybe run it about 2 turns out to 2 1/2 out and try that. Air filter good? Any air leaks in the carb boot?

lilatv
04-30-2008, 03:38 PM
Im not really sure what the problem was. I remember two years ago it gave me trouble, so I put it up for the winter and thats where it sat.

Same problem I was having yesterday.

I took the carb apart and removed the handful of pieces that make up the tiny little carb, blew some cleaner through everything.

As a precaution, put a little silicone on the intake tube to head gasket.

Fired it up, gave me a little trouble, kept acting like it was loading up when Id take the choke off, then it just decided to idle choke off, now to suprise some kids. :)



I see you have a big red, I always wanted one of those, since the first time I sat on one...although, Id have to throw some of those tires with the tractor tread on the back or it just wouldnt feel right to me. :D