Thread: Carb Help!

What slot is the "C" clip on the needle? Lower it down a couple slots and test ride it. The main jet might be clogged or incorrectly jetted. Try the needle adjustment first and see how it runs. With no air filter it's running really lean and needs rejetted accordingly.

The original size main jet is a #58, it doesnt screw in its on an o-ring, see if its right, if so look for any evidence of someone tampering with the jet. Make sure the needle jet holder holes on the outside of the tube are clean there should be 4 small holes. And 100% it will not open up (it will idle thats all) without an air filter, dont bother touching height settings or adjusting, its a waste, get a filter on it. If everythings clean and up to spec, and you got a filter on it I guarantee it will run fine

This bike is original.....I bought it new 30 years ago for my daughter. I took the plug out and it is tar black. Maybe it is running way too rich. I just thought that since it dies when you open the throttle it was running out of fuel. When you break the throttle above idle it will pop then quit. I moved the needle down one notch, but no help. Help guys, I am weaing the screws out taking this thing apart. I tried it with the air filter on and it is no better. Any thoughts appreciated.....

Still sounds like its to lean, doe's it run any better with the choke on?

The main jet is most likely restricted. Replace it with a new one.

Had the same problem the other day with a CT 70. Check the gap setting of the ignition .Make sure it opens wide enough and check your plug. Sometimes they look good but don't work well

make sure the main jet is a snug fit. Had a mates 76 z50 popping and sluttering whenever you opened the throttle. Pulled the carb apart a dozen times to no avail before we realised the o ring on the main jet was stuffed and not sealing, therefore allowing fuel to pass around the outside of the jet and running super rich whenever the throttle was cracked. Annoying that we spent weeks stuffing around with it only to find it was a 20c o ring. Let us know how you go

Originally Posted by Mr.Horsepower

The original size main jet is a #58, it doesnt screw in its on an o-ring, see if its right, if so look for any evidence of someone tampering with the jet. Make sure the needle jet holder holes on the outside of the tube are clean there should be 4 small holes. And 100% it will not open up (it will idle thats all) without an air filter, dont bother touching height settings or adjusting, its a waste, get a filter on it. If everythings clean and up to spec, and you got a filter on it I guarantee it will run fine

You talking about the four holes in the main jet itself? All are to be open. I have replaced the o-ring on the jet....no change. This carb doesn't seem to complicated, but it is wearing me out. The only thing I haven't checked in the point gap....will try that next.I hate to spend over a hundred bucks for a new carb and it be something else. Any other suggestions I might try? Also, running with choke on doesn't seem to have much effect.....

no not the 4 holes in the main jet, the 4 tiny holes on the needle jet holder, the long flute looking thing that comes out after the main jet.