ATC70 Restoration

[91-YZ250-Chris]

Hey, well let me just intoduce my self, my name is Chris and I am a senior in high school. I just picked up a 1983 ATC70 from a friend down the street, it was running for a while, but then it stopped getting spark after a short run. After that the previous owner just let it sit so I bought it off of him to throw in the back of my truck and ride around at school during lunch on. Well as soon as I brought it home, I ordered a Clymer manual, top end gasket kit, and a points and condensor kit and spark plug for it. I am fairly well with working on the newer style of small Honda engines so I tore it down, rings were in spec, and so was cylinder. Then I checked the valve clearance, and all checked out, then I decarbonized the head. After everything was washed up and preped, I installed the new gaskets and rebuilt the top end. So after all that work, next came the ignition. I soldered a new condensor on it and replaced the points on it, just to be safe. Then the spark plug was gapped and everything installed. Well, I went to fire it up and the motor has great compression, but still no spark.

I am not very familiar with points type ignitions so I did the best I could. Am I correct in saying that the points are actuated via the flywheel? I put the points to their furthest setting, bolted on the flywheel and then through the hole, I set the point on the flywheel and tightened everthing up. Was I doing this correctly? It also looks like on the inside of the flywheel, where the point ride, I can see the notch made for the ignition timing, and it seems like there is no lobe to open up the points. Could this be my problem? And if it is, where could I buy another flywheel? I have pictures of the inside flywheel if I need to post them. I did some research and saw members talking about gapping the points, would this apply to me? This clymer manual doesnt seem to get too specific of testing the ohms of say the coils and such.

Hopefully, I will take it down to the frame and rebuild it back up to 1983 specs.

Thanks Again for reading through all of this, I'm just another guy trying to get 1 more 3 wheeler back on the roads,

Chris

91 YZ250
83 ATC70
79 GT80
89 XR250

[225dx]

First off unplug your kill switch so we know thats not the problem. If still no spark then gap the points about 1mm and work from there. While your points cover is off look at the end of the cam that is your points lobe. Check your stater also.

[grundlegrabber]

Of course gapping the points applies to you! Do you think you are exempt from the rules or something? Open up that manual of yours and read up on setting the air gap. The lobe on the flywheel is slight, and you may just not be noticing it. If the points plate isn't set right, they won't open at all. If the're too far away from the flywheel, the cam won't ride on the lobe and they will never open. Too close to the flywheel, and they will open too much or for too long. You gotta have them set just right. Try adjusting the plate the other way, and turn the flywheel, see if they open. There is a spec for the air gap, which you will set when the points are fully open. I'm not particularly familiar with those models, but I've done it before and it's not hard to do.
Good to see a young'un getting interested in trikes. We trikers love to see people keeping them fixed up and working. Every time I acquire another machine for my collection, I take it down, clean it up, replace all the wear items with good quality parts, and put it together back to Honda specs. Sounds like maybe you have the same mentality. Good luck w/your project and welcome to the board!
~ Rob ~

[sandpuppi101]

Chris ,I am the master at these little 70's,and first off let me say welcome to the board ,and that I think you being in school and getting into trikes is awesome ! With these little 70's,it's always easy and stupid at the same time.So you say the lobe is missing on the flywheel ?,do the points at anytime open when they are gapped? You want the points gapped at .012-.016 max.If you are in that ballpark you are good.Timing should be achieved when the F mark on the flywheel just reaches the arrow which is on the recoil cover.This is btdc a few degrees,so that means that when the t mark is at the mark that is tdc.Now a little trick I use before you put the whole thing together is check for juice,and before you put it all together.With the flywheel on, points gapped ,and all entarnals good,hook up a test light to the black wire coming out of the motor,get a drill,yep a drill,or impact ,I think a 17mm socket, and turn the motor over via the flywheel.Remember rity tity- left lucy,go lefty lucy,or counter clockwise.Now take the plug out,and use your drill or whatever on the flywheel bolt and ,and starting slow turn the motor over,if using an impact be careful cuz that will loosen the bolt, that is why I suggest a cordless drill or something!! Check to see if juice is coming from the motor,with only the black wire,NOTE:make sure the other wires are disconnected,even the black one.Now if the test light is brite your in business,next go to the on/off switch,disconnect it set your ohm at 200 and put one side of ohm to each wire turn the switch on then off check all three positions,if you see the ohm says the switch is good and you have juice coming out of the motor than doing my math that tells me that the coil is bad or a bad ground but it deffintly narrowed it down to one specific area! I hope this will help you,if you need more help just ask, and keep them grades up!!!!!!!

[91-YZ250-Chris]

Thanks for the help guys, I just got back from vacation and will be performing the work on it tonight. Yes, the gap is 0.3-0.4mm (0.012-0.016in). They have the steps in the manual, just hidden away not in the eletrical section, clumsy me I skipped over it. Thanks for the info guys, and hopefully 1 more trike will be back on the road.

Chris

[91-YZ250-Chris]

GREAT NEWS! after a quick idle adjustment, she purrs like a kitten. Now that its up to factory Honda specs, what aftermarket parts make the biggest difference, engine performance wise. I have seen a "Cobra" exhaust system for it and hoped that some of you might own a system, any input. I am going to head up to the cycles place near me and pick up a UNI since the stock airbox is MIA. Any reccomeded jetting issues? Thanks again you all!

[brapp]

a cdi conversion bigger carb a 88cc kit from betrice cycle and a cobra pipe( the only one available) is what i will be doing someday soon.