Thread: Carb Choke Spring Missing

Like many here I am having problems tuning my carb. I have a 79 CT70, some time ago the cap came off and the little spring inside the choke cap broke off. I fixed it with a tighter spring which appears to affect how the air mixture is comming in.

If I play with the choke half on while riding I get better performance depending on speed. I think the spring was used to regulate this. Is there anywhere I can get a replacement spring? Or is this a critical component?

Thanks

-D

Try www.dratv.com or www.hondanuts.com. They have just about everything for this little bikes.

Thanks, but Ive scoured all the parts sources, even looked at the Honda fiche, and from I can tell they dont sell the top end of a carb seperately. I really want to avoid buying a $100 carb just to fix this spring issue.

Check ebay.com I think I remember seeing one on sale there... I'll post the link if I see it again.

The spring under the cap where the throttle cable goes into the carb is the throttle return spring. It doesn't really have any effect on the mixture. It just makes sure the throttle slide goes back down when you let off on the throttle.

Actually im not referring to the throttle return spring, the spring I am referring to is actually inside the choke switch on the carb.

On the 79 CT70s there is a black choke switch on the side, the choke switch has a cap you can remove, inside the cap is a spring which is used to pull the carb baffle (metal plate in carb used to choke).

When the choke is on the metal plate is forced closed to ensure a rich mixture, however when the choke is off the metal plate opens in a spring loaded fashion. Im assuming depending on how much throttle you give, the spring loaded baffle opens or closes more based on the air getting sucked in the air intake portion of the carb.

I will try to post a scematic. Thanks all for the help!

-tb

Here is the part i am referring to.

I too am missing the choke spring on my '80 ct70. Both the spring and the cap were gone when I bought it. Had Durden not have posted his question, I never would have known there was supposed to be one.

Would somebody mind snapping a picture just so I can see what it looks like (with the spring visible) I might have to fashion something myself by how Durden's search is going.

Thanks.

Earlmo, I will get you a pic of the spring. After further investigation it looks like the spring is only used when the choke is on, so i dont think its a bug deal if you rig up your own spring.


As for the cap, I bought mine for $3.50 at Betrice here:

http://dratv.com/dratv/choksprincov.html

It worked fine on my 79 ct70.

Thanks Durden. Unfortunately Beatrice will not ship to Canada.

Yeah, right now, I have to hold the choke plate closed until the bike warms up a bit. Rather a pain, expecially when kicking it. I'll probably use something like a bottle cap in the meantime as the cover.

If you think it's worthwile, maybe also snap a pic of the spring removed from the carb (with a penny for comparison).

Thanks again.

eem