My new to me ct70

ronzrx

Member
Been working on a 1970 ct70 a friend gave to me. Frame #128365 Engine #128011 build date 11/69. Been sitting for 12 years 2,640 miles. Got it running with new condenser and Chinese carb. Rode it a little timing chain was loose, took it apart going to put in new one. Getting valve job bored .25 over new clutch have factory carb rebuilt ready to put on. Should have all the parts and machine work done by the end of the month can't wait to get it put back together! Found a lot of great info here thanks everyone!
 

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red69

Well-Known Member
Been working on a 1970 ct70 a friend gave to me. Frame #128365 Engine #128011 build date 11/69. Been sitting for 12 years 2,640 miles. Got it running with new condenser and Chinese carb. Rode it a little timing chain was loose, took it apart going to put in new one. Getting valve job bored .25 over new clutch have factory carb rebuilt ready to put on. Should have all the parts and machine work done by the end of the month can't wait to get it put back together! Found a lot of great info here thanks everyone!


Hope you meant .025", not . 25".:)
 

ronzrx

Member
Well I got it all put back together yesterday. New piston,rings, valve job, all new cam chain and associated parts. Had to replace rocker arms and cam had some wear valve lash was tight. Chased petcock screw holes in factory carb put new screws in. Soon as I turned the gas on it poured out petcock great! Took factory carb off put chineese carb on that I first got it running with. Turned gas on its leaking a little somewhere went to start it but it idled high so I shut it off. Started it again it started idling high again so I shut it off. Went to bed this morning put a zip tie on fuel line stopped leak I think. Every since I changed the 50 year old hard fuel lines to new ones they have leaked at the carb. Now this morning it wont start checked battery its good new also. It all of a sudden has no spark 12 hours later. I have spent about $1700 to freshen this bike up mechanically and cosmetically. I drained the gas set engine to TDC put bbq grill cover on it I QUIT. Maybe it will run again someday but not anytime soon!
 

OLD CT

Well-Known Member
Do some checking here... No spark may just be a fuel fouled plug. You may have installed the carb slide 180 degrees out. Insure that the slide slips all the way down in the bore. As far as the new china carb leaking, they sometimes do with gas that has ''ethanol''... Try to source ethanol free gas and pour it in with the gas on and let it swell the rubber bits/seals, petcock packing back into shape. It usually stop overnight. Do this in a ventilated safe space with a pan and or a towel so you don't ruin the paint. Don't give up yet. ;)We got you!!!;)
 

ronzrx

Member
I think the carb slide was in backwards, the brass hose nipples on carb were not seated all the way and I had the hoses on backwards. This was 9pm saturday night I worked 1am to 9am mowed grass worked on bike on and off all day, was long day way past my bed time and no nap! Took carb off this morning and figured all of that out. Still have no spark today it started last night twice ran before top end rebuild. I replaced original condenser when I first got it running everything looks ok need to find spark. Battery good fuse by battery good? Won't you tell me where has all my good spark gone!
 
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OLD CT

Well-Known Member
Un screw the spark plug cap, cut off a 1/4 inch of the coil wire, re install and re test. Quick and easy and worth a shot before having to double check the point gap. It may have moved. Set points to .016
 

ronzrx

Member
Un screw the spark plug cap, cut off a 1/4 inch of the coil wire, re install and re test. Quick and easy and worth a shot before having to double check the point gap. It may have moved. Set points to .016
Hey thanks cut 1/4" off tried it again thought I saw something. Turned overhead light off an drop light off put glasses on have very weak spark. When I got The bike after sitting for 12 years same thing weak spark. I put new carb on, new not oem condenser and it started and ran good except cam chain noise and little smoky. I think condenser is bad again. I'm going to order oem points and condenser and have to figure out how to change points and do this home made timing light timing set. Points are 1970 original
 

OLD CT

Well-Known Member
Leave the condenser alone as long as there is no solder or wiring touching the metal on it. That will give a no spark condition. Just get new points and gap them at TDC. I don't use a light. It will fire right up. I thought you had new points!!! The condensers rarely go bad. The old ass points are to blame here! Get a quality set not the cheap chinese. You will be cruising in no time! Stay away from ethanol gas also. Lowes/Napa sells ''tru fuel'' if you don't have gas stations with E free gas. Pricey but worth it! It will last when stored, just drain the bowl and set to TDC and turn the gas cap vent to ''off'' like you have mentioned.

Looking forward to good news soon...
 
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OLD CT

Well-Known Member
Don't forget a ''ultra light'' coating of dielectric grease on the inside of the flywheel, the ''points cam'' and a good amount the points ''felt''. Work it in the felt.
 

ronzrx

Member
YES! I couldn't wait so I put the chineese points that came with the condenser in. Went to lowes bought a good soldering iron re did the crappy solder job I did before and it RUNS!!!!! I did order good points and condenser going to get it broke in while it runs. Has chineese carb on it now need to look at factory carb again. Raining today in kansas city, tomorrow I can ride it. Got my antique license plate insurance ready to go! Thanks for all the help. After its broke in a little I have to take the right side apart clean oil spinner, change screen, put new clutch plates and springs in to haul my 6' 200# fat ass around. Thanks again for the help. I'm sure I will have problems when I take the right side cover off don't think it's ever been off screw heads are perfect Thanks Ron!!!
 

ronzrx

Member
Well it did run. Ran it 4 times today 5 min each time revved it a little was raining so didn't ride. Went to start the 5th time after dinner no start, guess what? No spark!! Point gap good, solder job looks good pulled flywheel again for the 50th time. Started each time in 1 or 2 kicks lights worked sounded good. I like spark have never had anything against it. Why does spark not like me and my ct? Well today is over for me will try to find sparky another day
 
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Gary

Well-Known Member
It is possible with just sitting there basically idling you could have fouled the plug. Try a new one- should always keep a couple on hand anyway. As a teen I had a Triumph that gave me fits. Pull the plug and it would spark put it back in and it would not go. Push it down the drive sometimes it would go but most of the time I'd have to push it back up. Put in a new plug and off I'd go,finally figuring out that under compression it would not spark. Today that Triumph would be worth quite the sum,I spent more time wrenching than riding- have only owned Honda's since because of it.
 
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ronzrx

Member
Well I have new honda points and condenser on order. Going to pick up a new spark plug even though I have 2 used ones already. Put the cover back on it this morning going to step away for a while. Try to find someone in my area to put new points and condenser in and make it spark.
 

OLD CT

Well-Known Member
Put the good points in and retry. Also if you want to, spray some carb spray and blow gun off the points. They sometimes have a coating on them to prevent premature oxidizing from the manufacturer. So when you get the new points, hose em down while they are still in your hand.;) All 4 of my CT's have this CDI conversion now, very good first kick starting and trust it to ride far from home. Very reliable.
IOW, points suck!

cdi conversion.jpg
 
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kirrbby

Well-Known Member
Most of us hate electrical problems.
Get in there with some fine emory cloth...400 grit if you have it. Sand the point contacts to get rid of any coating...clear coat, or any carbon or dirt, etc. Then clean the contacts...nice and clean. Then reset the points. I know you've probably done that too many times already...recheck/reset the gap. We like .016" (inches). Check for spark. If no, try setting the gap a little smaller/bigger...the check spark again.

Pull the flywheel. Make SURE the points cam, on the back side of the flywheel isn't rusted or dirty.

While the flywheel is off...look REALLY close around your stator. Make SURE there are no wires being rubbed by the flywheel. ANY bare wire that is close enough to ANY metal, for a spark to jump, could be grounding out your spark. Make VERY SURE of that. One time...VERY SURE...rule it out.

While the flywheel is off...take some pictures. Nice, close, clear, pictures.
Show us those pictures.
 
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