Cam chain adjustment

ronzrx

Member
New owner of 1970 ct70 2,670 miles. When its warmed up it sounds like the cam chain is loose. I don't see the cam chain tensioner locknut and lockbolt by the shifter like it says in the manual I have. I see the cam chain tensioner sealing bolt across from the oil drain bolt. How do I adjust it? I put the strongest pair of reading glasses on in the house still can't see locknut by shifter. Do I need to take shifter off to see lockbolt? Thanks for any help Ron
 

Attachments

  • 20210402_134519.jpg
    20210402_134519.jpg
    2.3 MB · Views: 146

OLD CT

Well-Known Member
Hi Ron, The cam chain tensioner bolt is on the shifter side, underneath, across from the drain plug. However the model you have, a K0, does not have an ''adjustment'' or lock nut. It's only a spring and tensioner under the plug. Which means you need to change the cam chain and any other part associated that is worn. Sorry to be the bearer of bad news. The K1 model CT70 and up has the ''adjuster'' under the plug and the locking part is on the shifter side, under the flywheel cover ''visible'' looking at the bike .


IMG_0979.jpg Pic of a K1 and up adjustable style.
 
Last edited:

ronzrx

Member
Thank you my eyes are not that good but I knew with glasses I still couldn't see that adjuster. With only 2,500 miles is chain and stuff worn out already? I know mileage is correct. It sounds like chain noise but I have never herd chain noise for sure. Learning along the way, mostly had 2 stroke dirt and street bikes in my youth. Will have to wait until winter if I have to tear it all down like riding it, had not run for 10 years when my friend gave it to me he got it in 1981 I have been taking it easy on it when I ride it Thanks for the help I will look into what all it takes to replace those parts.
 

ronzrx

Member
I think next winter I will rebuild engine. Its smokes some until its warmed up and smells rich, does have chinese carb on it right now though. Factory carb was clean but has screws that won't tighten on petcock and on the screen on other side. I need to find a replacement float bowl so I can put factory carb back on. Is it usually just cam chain that stretches or do the gears and other parts wear? Thanks for help everyone Ron
 

Gary

Well-Known Member
Mine had about that on it and the chain was worn out. It can be changed with out a big tear down. Make sure it's on TDC,pull the cam cover,pull the flywheel and the stator plate and lay the bike down on it's right side. Remove the cam sprocket,the guide roller in the cylinder and pull out the chain. Check the sprockets for wear, including the oil pump drive sprocket, replace the guide roller,chain,maybe the tension roller if needed and replace the rubber head of the tensioner push rod. That will buy you some time before you decide to if you want to rebuild the engine. Better than leaving the chain grind away on the head and cylinder. Sounds like more work than it even is.
 

ronzrx

Member
Thanks Gary I just looked up all those parts about $100 if I order everything including the gears. I want to ride it this summer just got it running about a month ago. When you pull the stator plate does it unplug and come completely off or just move it out of the way. That sounds a little scary. I have had the flywheel off replacing condenser just never removed a stator thanks again for all the info Ron
 

Gary

Well-Known Member
You can either move it out of the way or just unplug it. Personally I’d unplug it and get it out of the way, nothing to it- it won’t affect the timing. Might want to order new o rings for the stator though, 1 large one goes around the circumference of the stator 2 small ones for the mounting screws.
 
Top