ATC 70 Carb ???

[knsmodels]

I just got my son a 70 and I think the carb is adjusted incorrectly.....there are 3 adjustment screws.....I know the one is the idle adjust....does anyone have the factory settings on the other two....I have not got the sevice manual on this one yet so any help would be appreciated.....Thanks.....

[SWIGIN]

any pics??......one of the 2 is a air screw...and normaly thats around 1 to 2 turns out

[DaMadman]

My guess on the 3 adjustments and it is just a best guess is Idle, Low speed air/fuel and High speed air/fuel.

Old Mechanic told me along time ago that "most" carbs, a good starting point is to seat the needle valve VERY GENTLY and then back it out 1- 1/2 turns and adjust by ear from there

[knsmodels]

http://www.knsmodels.com/truck/70carb.jpg


1....is idle adjust ??
2......????? setting???
3.......?????setting???

[slothminx]

No.1 = The ide screw, This has no specific setting. just screw in until the engine idles but when in gear does not pull away. Out if its pulling.

No.2= The Idle air mix screw, The default is to lightly screw the screw all the way in and then back it out 1 1/2 turns. Once you have No.1 set you play with this to give the highest idle speed.

No.3= the Carb bowl drain screw, Use this is you think there may be water in the bowl or if you want to check theres fuel in the bowl.

You might want to give the carb a good clean, looks like theres some alum oxide/ old fuel scum behind where the petcock mounts. Pop the two screws out that hold the bowl on and clean in there with petrol/carb cleaner and take the two brass jets out and make sure there clean.

Excellent picture of the carb BTW!

[knsmodels]

Thanks....Sloth.....those are the answers I was looking for.....thanks for the comment on the pics as well......this is an extra carb and I will be sure to clean it up better before I install......it was scummed up pretty good under the petcock....:TrikesOwn