80 ATC 110 help

[Boostedb16a]

Hello I recently bought a 80 ATC 110, currently runs and rides great except it will not idle what so ever. Doesnt bog all crazy anything, Here is a list of things I've done/changed.

Changed the plug
Oil change
New points in spec at .013 book says .012-.016
New crap eBay carb "runs great and idles on my friends 110"
Tried my buddy's carb that works great on his
Tried a clean OE carb still nothing on mine but great on his.
Checked stator looks fine to me.
Changed the clip on the needle no bogging
Have the pilot set at 1 3/4 great throttle response
Set float according to book still nothing


Bike will fire up first pull if you hold the gas, it will wheelie out the garage if you WOT but once again will not idle.

Gears work great high and low.

Only other thing I can think of is condenser/coil change maybe its a high low voltage?

[tri again]

Hi and welcome.
You may want to check your spark advance plate.
you say 110 with points?
there should be a couple tiny springs on a plate that rotates slightly
behind the points.
They can get stuck in an advanced position and do what you describe, especially
if your parts work ona nother machine.
Any chance of checking with timing light?

Hope that helps.

[Boostedb16a]

Have not checked with a light figured it was good cause it runs excellent other then idle. I'll pull the points and cover tonight and see if they are free or binded. Thanks for the reply

[Boostedb16a]

How do you check with a timing light on these motors now that I think about it.

[tri again]

you can download free service manuals right here on 3 ww.

so? you know what I mean by advance plate?
when you rev the engine, the plate rotates to advance the timing.
and they can get stuck in the advanced position. run great off idle but too far advanced to idle.

valves set ok?

I forget exactly how to check timing...too many machines in the 'shop' to remember my own name these days.

[Boostedb16a]

Valves are great and I'm assuming the advance is behind the point plate in front of cam/camgear?

[Boostedb16a]

Valves are great and I'm assuming the advance is behind the point plate in front of cam/camgear?

[trike savior]

The advancer is behind the points plate. It has 2 hinged arms with 2 small springs holding it to the main body. The springs often rust and break or disintegrate. Also make sure it moves. The main body is 2 pieces and need to move independent of eachother. They can rust and become 1.

Timing it is easy but download a manual. Either Kbonly or Oscarmayer have them for free. A regular automotive timing light hooked to a car battery is all you need. Hook the inductor ring around the spark plug wire and make it so the F mark on the flywheel lines up with the mark on the engine case.

[Boostedb16a]

Pull the cover and points then lubed lightly the hinge points and everything has a surface rust look but both move independent. Put the points plate back on and the points but think I messed up cause while looking at the advance springs and moving them I lightly rotated the motor they didn't come out or anything but was seeing if they sling out automatically or as the rotation speed increases. Now the little guy sputters and dies so I'm gonna pull them back off and check it again and also use a feeler to set the points at .013 again I just eyeballed it and assume that's what the issue is.

[Boostedb16a]

If it starts again but doesn't idle could it be the condenser and coil and if so where would I find one. I find coils on eBay but no condenser on it and they look like car coils in a way.

[Boostedb16a]

She's back up and running just no idle still, I have the pilot at 1 3/4 and needle clip 4th down and points set at .013. I'm thinking its in the coil and condenser I can't see why it'd fire first pull every time though.

[Lucas_riley]

I was having similar problems with my 1977 atc90 and 1983 atc110. I could get them to run fairly well, but never idle for more than 10 seconds or so. So on the 110, I completely cleaned the inside of the carb, made sure the pilot screw was in the original factory setting (factory said 1 turn to 1 and 1/4 turn out from all the way in). Then replaced the pilot jet. It still wouldn't stay running, so I took the carb cap off and checked the fuel needle and the clip was on the second lowest setting. I adjusted it to the middle setting. Now it runs great and actually idles. I turned the idle speed screw up so It would idle high, then adjusted it down to where it would want to die, then came back a 1/4 turn.
It worked for mine, hopefully that helps.

[Boostedb16a]

Yeah I've tried every needle setting and it runs best at the 4th from the top and 1 3/4 out on the pilot. I've cleaned all 3 carbs and they all 3 stay running and idling on my buddy's 80 ATC 110 but not mine. I have great fire from the coil, I cranked her over yesterday to check spark and she bit me pretty good so spark is ok, only other thing I can think of is rechecking my valve lash maybe its to tight and I didn't see it the first time. They was set to .003 on them and possibly checking all the timing marks to confirm its in time.

[Boostedb16a]

I have purged the exhaust lots if black packing is coning out, I'm going to try and cook it out tomorrow and try my buddy's exhaust on mine to see if its choking the motor cause if you put your hand behind the tail pipe you can hardly feel any pressure.

[Boostedb16a]

Took the baffle out again today and tapped on the exhaust more black packing and soot came out. It now runs for about 1 minute idling then just dies completely. Still runs great riding but does have a slight bog when switching to the next gears tried upping the fuel to 2 turns out but same results with 1 3/4 so I put it back. I'm assuming it is clogged and choking the motor and I rechecked my valve lash and have no movement on the intake side and very little on the exhaust. So what I can gather is to relash it and then pull the exhaust and put it in a fire and hope to burn anything out that may be blocking the passageway. Hopefully she will idle after that and my work can be done and let the kids play on it.