Jump to content
Sign in to follow this  

2001 xr70 carb/tune question

Recommended Posts

A few days ago I completley removed carb and dissassembled, ultrasoniced all parts at work. Reassembled and began to tune.

 

Problem: Warm it up and come to a stop on level ground, sometimes the idle will slowly speed up. Or if you lean it to the left the idle speeds up. Lean it to the right no change at all stays runnig normal. You can tap the kill switch a few times an it comes down to a nice idle. ??? Do i not have the pilot/fuel screw right? Float?

 

 I went for a ride with him yesterday and he must have rode for the first 15 minutes with the choke on. I was baffled that he could ride so long and it ran normalish. He just noticed it was stalling. How could it be that lean that it will run choked. I mean he was blasting across fields full throttle in 3rd.

 

All stock, completly clean carb.

 

 

Thanks

Share this post


Link to post
Share on other sites

A few days ago I completley removed carb and dissassembled, ultrasoniced all parts at work. Reassembled and began to tune.

 

Problem: Warm it up and come to a stop on level ground, sometimes the idle will slowly speed up. Or if you lean it to the left the idle speeds up. Lean it to the right no change at all stays runnig normal. You can tap the kill switch a few times an it comes down to a nice idle. ??? Do i not have the pilot/fuel screw right? Float?

 

 I went for a ride with him yesterday and he must have rode for the first 15 minutes with the choke on. I was baffled that he could ride so long and it ran normalish. He just noticed it was stalling. How could it be that lean that it will run choked. I mean he was blasting across fields full throttle in 3rd.

 

All stock, completly clean carb.

 

 

Thanks

Float is set from the factory so i will initially rule that one out.  Did you just clean it, or also get a carb kit to replace gaskets?  When yu dipped it, did you removed all the plastic and rubber pieces?  If you didn;t, those would have become damaged creating a possible air leak somewhere.  That could explain it running OK with the choke on.  

Share this post


Link to post
Share on other sites

Ok I worked on this some more as I had to. Seems I could tweek the tune and get it right then the next day it was off again. I started it yesterday and it did not want to take the gas. My son had ridden it and ran it out of gas so all kinds of things were going through my mind. Did it get something in the main? Anyway I took it apart and looked through the jets. I also greesed the  "o" rings just in case I had a vacuum leak. For what ever reason and I'm believeing a vacuum leak. It's now perfect. Starts well it always started, idles and takes the gas. All smoothly and with that power I expect from a 70.

Share this post


Link to post
Share on other sites

Fuel screw may be missing the o-ring and or washer. This is real common to leave out when rebuilding carbs this small.

Take out the fuel screw and be sure you have the washer and oring. check up on the hole to be sure the old oring is not jammed up inside.

Share this post


Link to post
Share on other sites

There is no o-ring or flat washer on the XR/CRF70 air screw, just the tension spring.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×