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View Full Version : atc 110 doesn't rev up



buffalobill
10-20-2011, 07:31 PM
I have a 79 atc 110 that I thought needed a carb rebuild. it would only run well with the choke on. So, i rebuilt it. new low speed and main jets, new needle, new af screw and idle speed screw. bolted it back together and it fires right up. idles smooth, but it won't rev up past 1/2 throttle. I thought that i had the needle clip setting wrong and it was running too lean. i pulled it out and put it all the way up, and fired it back up. same thing. it hits a certain rpm and just starts to sputter and die. the plug looks like its running too rich, but i pulled the plug with the first needle setting and it looked rich then as well, i just assumed that since it was an older plug and the carb was in need of a rebuild, that it looked like that before. it has new points, and they are set properly, and the valves have the proper clearance, they arent being held open.

I get a decent spark at idle, when i am testing it, or when i am pulling it over. It does arc at the points plate "occasionally", but it doesnt seem to be enough to where it would cause the problem. i watched it while it was running, and it does not arc more when i rev it up.

Could this be my coil going bad? I have already had my condenser go bad, and i spliced in an atc 90 condenser, since the 110 coils are not a serviceable unit. Are there any tests for coils that would show if it was getting weak? would putting an atc 90 condenser on a 110 coil do this? can i just throw on the atc 90 coil i have as well? I know the wiring plugs are different, but i could just hardwire it if it works.

shortline10
10-20-2011, 08:18 PM
Are you running the stock air filter ?
The atc110 needs alot of intake back pressure to run right so make sure you have no leaks on the intake side / rubber boot / airbox exc .



I have a 79 atc 110 that I thought needed a carb rebuild. it would only run well with the choke on. So, i rebuilt it. new low speed and main jets, new needle, new af screw and idle speed screw. bolted it back together and it fires right up. idles smooth, but it won't rev up past 1/2 throttle. I thought that i had the needle clip setting wrong and it was running too lean. i pulled it out and put it all the way up, and fired it back up. same thing. it hits a certain rpm and just starts to sputter and die. the plug looks like its running too rich, but i pulled the plug with the first needle setting and it looked rich then as well, i just assumed that since it was an older plug and the carb was in need of a rebuild, that it looked like that before. it has new points, and they are set properly, and the valves have the proper clearance, they arent being held open.

I get a decent spark at idle, when i am testing it, or when i am pulling it over. It does arc at the points plate "occasionally", but it doesnt seem to be enough to where it would cause the problem. i watched it while it was running, and it does not arc more when i rev it up.

Could this be my coil going bad? I have already had my condenser go bad, and i spliced in an atc 90 condenser, since the 110 coils are not a serviceable unit. Are there any tests for coils that would show if it was getting weak? would putting an atc 90 condenser on a 110 coil do this? can i just throw on the atc 90 coil i have as well? I know the wiring plugs are different, but i could just hardwire it if it works.

buffalobill
10-20-2011, 09:55 PM
yes, actually, the entire intake system, right down to the snorkle, is totally intact and in good shape!

effort=results
01-18-2014, 06:45 PM
I have a 79 atc 110 that I thought needed a carb rebuild. it would only run well with the choke on. So, i rebuilt it. new low speed and main jets, new needle, new af screw and idle speed screw. bolted it back together and it fires right up. idles smooth, but it won't rev up past 1/2 throttle. I thought that i had the needle clip setting wrong and it was running too lean. i pulled it out and put it all the way up, and fired it back up. same thing. it hits a certain rpm and just starts to sputter and die. the plug looks like its running too rich, but i pulled the plug with the first needle setting and it looked rich then as well, i just assumed that since it was an older plug and the carb was in need of a rebuild, that it looked like that before. it has new points, and they are set properly, and the valves have the proper clearance, they arent being held open.

I get a decent spark at idle, when i am testing it, or when i am pulling it over. It does arc at the points plate "occasionally", but it doesnt seem to be enough to where it would cause the problem. i watched it while it was running, and it does not arc more when i rev it up.

Could this be my coil going bad? I have already had my condenser go bad, and i spliced in an atc 90 condenser, since the 110 coils are not a serviceable unit. Are there any tests for coils that would show if it was getting weak? would putting an atc 90 condenser on a 110 coil do this? can i just throw on the atc 90 coil i have as well? I know the wiring plugs are different, but i could just hardwire it if it works.

So what did it end up being having same trouble with atc 90

tri again
01-19-2014, 07:29 PM
Do those have that mechanical spark advance, plate with springs?
runs off the cam?
or do I have my trikes mixed up.
I remember quite a few of those gettign rustydust and some with broken springs.
They really need attention periodically since there is no real lubrication
in there except for assembly lube.