1973 ct70 no spark

KennyCT

KennyCT

Member
So I posted about my ct70 yesterday after I picked it up. I knew it was having spark issues so I went ahead and picked up a new spark plug, but it turns out that must have not been it. The bike currently has no battery and I'm wondering if that would be the cause? Ive read around and ive heard there is a way to jump it without a battery, but I'm not quiet sure what wire to use and where to put it. Ive never worked with a bike like this so it is quiet a learning curve for me. I understand it could also be the contacts on the condensor. How do I tell if it is the contacts that are the issue? I'm just overall confused because I dont really know where to start. Pictures included below.
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KennyCT

KennyCT

Member
red69 said:
Run it without a battery and kiss your light bulbs goodbye.
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I understand that, it doesnt even have bulbs right now. I'm just currently trying to get it started, ill be getting a battery soon though. Is it possible to start it without the battery? If so, how?
 
cjpayne

cjpayne

Well-Known Member
Take a pic of your engine #'s. Trying to figure out if you have an SL70, CL70, CT70HK0, or CT70HK1 motor. I think the SL70 had its condensor mounted on the frame.

To hotwire the motor, take the black wire from the stator and connect it with the black wire from the HTcoil. You can use the choke as a killswitch when warm. Use the proper connectors(jumper wire) so you dont butcher your wiring.
 
KennyCT

KennyCT

Member
I'll have to take a pic of the engine when I get home from work. Would the condensor be the cylinder mounted underneath the gas tank, or is that the ht coil?
 
kirrbby

kirrbby

Well-Known Member
Looks like it says, CT70HE-144259

It also looks like the PO may have this bike hotwired already. Not sure why they needed the ground wire tho.
 
KennyCT

KennyCT

Member
kirrbby said:
Looks like it says, CT70HE-144259

It also looks like the PO may have this bike hotwired already. Not sure why they needed the ground wire tho.
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It makes sense that it may already be hot wired since the guy that had it before me said it was running on july 1st. I'm going to try cleaning up the contacts on the magneto. The distributer wire is Also split, so I may buy anew one soon. For now I'm just have the two split ends wrapped together.
 
A

allenp42

Well-Known Member
It does look like you have a HK0 4 speed engine in the frame. I also don't see a wiring harness either.

However, just to get a spark, you don't need anything but a jumper wire from the black wire on the 4 pin plug (assuming it has one) to the small black wire on the ignition coil.

Follow the wiring harness out of the stator to see if it's already hot wired? The cable/harness for the stator should be routed through the area of the frame where you also see the fuel lines. Just pointing this out as info.
 
cjpayne

cjpayne

Well-Known Member
The round thing underneath the gas tank is the HTcoil(sparkplug wire coil).

Underneath the tank, I think I see 3 disconnected wire terminals.

The silver cylinder jug made me think it might be an SL70 motor, but who knows for sure.

I also don't see any wire harness. Sometimes people just gut them out and hotwire the rest.

Spin the flywheel around and see if you see a condensor in there.
 
KennyCT

KennyCT

Member
I'm thinking it has something to do with the magneto, since when I first got the bike I could get it to occasionally spark. I'm gonna buy a flywheel puller and clean the contacts in the magneto since I'm think it may be pitted. I'll also be buying a new htcoil down the road since there not to much, and my spark wire is completely torn in half.
 
OLD CT

OLD CT

Well-Known Member
You would be best served to try and find a left side case or better yet the correct engine for the vin number on the neck tag, for resale and overall value. I wouldn't bet the farm the guy had it running on July 1st. Maybe it was running in his own mind. o_O :ROFLMAO: Post up the neck tag numbers and someone might be able to find one. Try cleaning and adjusting the points. The flywheel doesn't have to come off to do that. Set the gap to .016 A emery board from the wife would clean em, then blast em ''while they are open'' with brakkleen or carb cleaner. You may need that coil right now too!
 
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KennyCT

KennyCT

Member
I have the side case for the engine already, I had just set it aside for the pic. Also, how do I go about setting the gap without removing the flywheel?
 
OLD CT

OLD CT

Well-Known Member
Points cannot be adjusted/set with the flywheel off. The ''points cam'' that opens the points is on the flywheel. The only time you need to remove the flywheel, is when you are installing new parts. You remove the sparkplug, turn the flywheel ''counterclockwise only'' till you line up the T on it with the notch in the case and make sure the piston is at ''top dead center'' with a small screwdriver into the plug hole. Now you can see the points thru the slot in the flywheel, there is a screw that you loosen and set the points with a feeler gauge. .012 to .016 16 is better as the points rubbing block wears and the gap gets smaller, not bigger, closing the points even more. It's a good time to buy a manual if you do not have one and or watch some videos on the topic.
 
KennyCT

KennyCT

Member
OLD CT said:
Points cannot be adjusted/set with the flywheel off. The ''points cam'' that opens the points is on the flywheel. The only time you need to remove the flywheel, is when you are installing new parts. You remove the sparkplug, turn the flywheel ''counterclockwise only'' till you line up the T on it with the notch in the case and make sure the piston is at ''top dead center'' with a small screwdriver into the plug hole. Now you can see the points thru the slot in the flywheel, there is a screw that you loosen and set the points with a feeler gauge. .012 to .016 16 is better as the points rubbing block wears and the gap gets smaller, not bigger, closing the points even more. It's a good time to buy a manual if you do not have one and or watch some videos on the topic.
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Thanks for the help, ill have to try and do that sometime soon, ill let you know how it goes. Found a few youtube videos on the topic.
 
KennyCT

KennyCT

Member
The points seem to always be shut, I just tried adjusting them, but they always want to snap back shut. I try to move just the top contact after loosening the screw, but both move together. I took a picture of them included below.
 

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OLD CT

OLD CT

Well-Known Member
The points are all screwed up, they are not making good even contact with each other. Order new points. There is a slot in the points and on the case to stick a slotted screwdriver in and adjust them.
Leave the adjust screw only slightly loose, not ''too loose'' to hold an adjustment.
 
6

69ST

Well-Known Member
OLD CT said:
The points are all screwed up, they are not making good even contact with each other. Order new points. There is a slot in the points and on the case to stick a slotted screwdriver in and adjust them.
Leave the adjust screw only slightly loose, not ''too loose'' to hold an adjustment.
Click to expand...

Can't agree enough with that statement. This is may take over the #1 spot on the list for most f*cked-up breaker point assembly on a CT70.
 
6

69ST

Well-Known Member
cjpayne said:
Take a pic of your engine #'s. Trying to figure out if you have an SL70, CL70, CT70HK0, or CT70HK1 motor. I think the SL70 had its condensor mounted on the frame.

To hotwire the motor, take the black wire from the stator and connect it with the black wire from the HTcoil. You can use the choke as a killswitch when warm. Use the proper connectors(jumper wire) so you dont butcher your wiring.
Click to expand...

Looks like "CT70HE" on the engine SN pad...viewed on my desktop monitor
 
cjpayne

cjpayne

Well-Known Member
racerx said:
Looks like "CT70HE" on the engine SN pad...viewed on my desktop monitor
Click to expand...
Must be an HK0 then. The silver jug was throwing me off. I dont see a neutral switch either. Don't know if that chain could be soaked and reused, but I definitely would replace it soon.
 
cjpayne

cjpayne

Well-Known Member
OLD CT said:
I wouldn't bet the farm the guy had it running on July 1st. Maybe it was running in his own mind. o_O :ROFLMAO:

Set the gap to .016 A emery board from the wife would clean em, then blast em ''while they are open'' with brakkleen or carb cleaner.
Click to expand...
Unfortunately, I was starting to think the same thing. Someone else may have jacked with it after he did.

I was always afraid that carb cleaner or brake cleaner would eat on the wire coatings on the stator coils, so I always use electrical contact cleaner or WD40(especially if water got in there).
 
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