honda c-70 throttle problems..

ok.. so I just got an 81 honda c-70, and I already had my 80 honda c-70, and the carb on my 81 is bad I think.. so I was going to switch them out.. and see how it ran.. and I couldn't get my throttle to work right.. it was kind of like the cable wasn't attatched.. but I didn't have time to mess with it too much, so I just switched it back to the other scooter.. the 80. and that one started doing the same thing.. what the hell did I do to my carb? I didn't take it apart.. I just took it off and put it on the other scooter.. they're identical bikes..


Re: honda c-70 throttle problems..

Did you slide it toofar up on the intake and jam the throttle slide? Just guessing here. don-ohio (:^D

Re: honda c-70 throttle problems..

did I slide what too far? I didn't slide anything that I'm aware of.. I could easily have just done something stupid and not noticed it.. I've only cleaned a carb twice, and this is the first time I've attempted to get a non-running scooter to run.. well.. I guess it runs.. but I'm working on getting it running well..


Re: honda c-70 throttle problems..

The throttle valve slide is probably not aligned with the throttle stop screw that protrudes into the carb. It is sitting on top of the screw and won't let the slide go down it's full range.

Not sure how you switched carbs.

Did you unscrew the carb top and lift it out of the carb and then install the other carb and reinstall the carb top?

Try unscrewing the carb top and slip it up out of the carb, moving it to one side and leave it hang.

Now twist the throttle on the handle bar and see if the spring in the loose hanging throttle slide assembly causes the spring to compress and release moving the throttle valve slide as you twist and release the throttle.

If it compresses and releases then your throttle and throttle valve slide assembly is working properly.

When you put the throttle slide back in the carb, make sure the slanted notch on the bottom of the throttle slide is aligned with the throttle stop screw that protrudes into the inside of the carb.

thanks don-o and zippy..

I got it all figured out thanks to me noticing my stupidity and to you guys help.. also, the yellow one mentioned above.. I got that figured out too.. its missing its main jet.. interesting. anyway.. I ordered one.. and I should get it in the next couple days.. but one last question: there were three jet sizes, 85, 88, and 90. I got an 88.. but I'm not sure if thats the right size.. any way to tell?

Re: thanks don-o and zippy..

Glad to hear you got it straightened out.

According the Honda Manual, #88 is the correct main jet for a 1981 model, #90 was for the 1980 model.

Slow jet (idle) is #35 if you should need it.

Where would we be..........

....without Zippy and ChrisMWH, and a bunch of other guys who help with `specialized knowledge'? Thanks, you two, and to all the other true moped mechanics on this forum that help everyone out. KUDOS! don-ohio (:^D

Re: Where would we be..........

got my jet today.. it runs like a champ! its probably the smoothest, most quiet bike I've ever owned.. 250 bucks.. and an 8 dollar part to get her up and running... hehe.. I'm awesome. thanks again to everyone who helped me..


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