Hi guys and gals!
It's been a while since I've posted I know, but I'm having a hell of a time with my son's CRF70 and was hoping someone here with more knowledge than me could help me out.
The problem: Bike starts fine and runs *ok* with the choke on. It will eventually die if you don't blip the throttle but the RPM is generally in the right place. Now, when you turn the choke off, the engine races like crazy. The RPM shoots up and seemingly nothing will bring it down. The idle adjustment screw does nothing. I can't for the life of me get it to idle nicely with the choke off.
What I've tried:
- Recently rebuilt the carb with the stock jetting. Pulled it apart again today to make sure nothing was amiss and everything seems ok.
- Tried lean and rich settings on the throttle pin (via the little clip adjuster)
- The air screw is at the stock starting point of 1&1/2 turns out.
- I've checked and adjusted the valve clearance to be within spec. (Intake valve originally had no play in it and I fixed it thinking that would for sure fix it...no dice)
- Air filter and spark plug are relatively new (only a couple of rides on them) and clean.
- Swearing. Lots and lots of swearing.
I did notice the tube coming from the airbox that clamps on to the carb looks a little beat up (like its pulling away from the airbox) but it's been like that since I've bought it. Could it be an air leak there?
Ok, sorry in advance for the long post. I really don't want to go to the dealer. Please help!
It's been a while since I've posted I know, but I'm having a hell of a time with my son's CRF70 and was hoping someone here with more knowledge than me could help me out.
The problem: Bike starts fine and runs *ok* with the choke on. It will eventually die if you don't blip the throttle but the RPM is generally in the right place. Now, when you turn the choke off, the engine races like crazy. The RPM shoots up and seemingly nothing will bring it down. The idle adjustment screw does nothing. I can't for the life of me get it to idle nicely with the choke off.
What I've tried:
- Recently rebuilt the carb with the stock jetting. Pulled it apart again today to make sure nothing was amiss and everything seems ok.
- Tried lean and rich settings on the throttle pin (via the little clip adjuster)
- The air screw is at the stock starting point of 1&1/2 turns out.
- I've checked and adjusted the valve clearance to be within spec. (Intake valve originally had no play in it and I fixed it thinking that would for sure fix it...no dice)
- Air filter and spark plug are relatively new (only a couple of rides on them) and clean.
- Swearing. Lots and lots of swearing.
I did notice the tube coming from the airbox that clamps on to the carb looks a little beat up (like its pulling away from the airbox) but it's been like that since I've bought it. Could it be an air leak there?
Ok, sorry in advance for the long post. I really don't want to go to the dealer. Please help!
for the db-A TEAM
