Crf80 carb Help PLEASE!
  • Chevydawg1
    Posts: 4
    Joined: Mon Nov 20, 2017 4:29 pm

    Crf80 carb Help PLEASE!

    by Chevydawg1 » Mon Nov 20, 2017 4:50 pm

    I put a new oem Honda carb on my son's crf80 and it would start dripping steady fuel out of the vent at random times. I decided to check the float level and it was a little off the factory .85 specs so I made adjustment. After lots of on and off to do adjustment on carb, now it will only crank on choke and will not even run with choke off. What could cause this? I'm very frustrated because it ran good except for the fuel running out of vent...now want run at all.
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    Re: Crf80 carb Help PLEASE!

    by Aussiecrf230 » Mon Nov 20, 2017 10:07 pm

    Where did you set the float level too?
    Did you raise or lower it?
    Was it letting fuel through when you finnished adjustment?
    The original overflow might have been caused by small amount of trash stopping the seat to close.

    If you are happy it is now correct you may have to adjust the idle mixture screw to get it to idle? Changing the float level can certainly change the fueling.
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: Crf80 carb Help PLEASE!

    by Back2-2 » Tue Nov 21, 2017 6:12 am

    "now it will only crank on choke and will not even run with choke off."
    I think you have got debris in the pilot jet. Those are the exact symptoms of a clogged pilot. While working on the carb it sounds like a little piece of something was floating around and now giving you issues.
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • Chevydawg1
    Posts: 4
    Joined: Mon Nov 20, 2017 4:29 pm

    Re: Crf80 carb Help PLEASE!

    by Chevydawg1 » Tue Nov 21, 2017 3:02 pm

    Thanks for the replies. I guess I will pull it again and pull the pilot and clean. Not sure if I solved the fuel dripping problem because I can't get it to run off of choke. I'll post results.
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: Crf80 carb Help PLEASE!

    by Back2-2 » Wed Nov 22, 2017 1:52 pm

    When you get it running again and it still has the dribbles - time for a needle to be replaced. Fuel dries out the tip and even a slight ring on the tip lets fuel by the needle and seat.

    Good luck and take your time, you'll get it ;)
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • Chevydawg1
    Posts: 4
    Joined: Mon Nov 20, 2017 4:29 pm

    Re: Crf80 carb Help PLEASE!

    by Chevydawg1 » Sat Dec 23, 2017 6:24 am

    After cleaning the carb multiple times, the bike starts, idles and runs great for a short period of time. Now the issue is that no matter what, after about 5 minutes of riding it starts bogging or just shuts off like its losing fuel or fire. I have a clear hose running from the new petcock to the carb and I know its getting fuel. Is it possible that the coil starts creating this when it gets hot or is it Vapor locking? I can let it cool down and it will start and run great and then start doing the same thing...bogging and then just stop running... if you can get it to start, it runs very rough. Very frustrating because I'm afraid its going to cause my son to wreck...he rides at a fast pace and you just don't know when its going to just die and that's not good on the technical terrain he is learning on. Please HELP me solve this!
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: Crf80 carb Help PLEASE!

    by Back2-2 » Sat Dec 23, 2017 8:20 am

    When it does that quickly loosen the gas cap. It could be a vacuum issue building in the tank. If that is it then the cap vent line check valve is either in backwards clogged or the cap internally is clogged. Seem many, many vent issues over the years. They can allude you for a long time until you find them. :(

    Otherwise the only suggestion would be that you are flooding after the 5 min run time. But that seems odd since it starts and runs fine for 5 minutes. :?

    Stator issues can also be really tough to find - they can be fine while cold then fault out when hot but that usually does not give "bogging" conditions it is more of a very erratic and miss fire condition. Would not hurt to go a ohm's / resistance check when it acts up just to eliminate the stator.

    Hope those ideas give you some direction to go.
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • Chevydawg1
    Posts: 4
    Joined: Mon Nov 20, 2017 4:29 pm

    Re: Crf80 carb Help PLEASE!

    by Chevydawg1 » Sat Dec 23, 2017 4:11 pm

    Thanks for the Help...I will try these suggestions...I was already thinking about the tank vent. You can just about set your clock when it is going to start bogging. He is wanting to do his first Hare Scramble next year and I want to get this sorted.
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: Crf80 carb Help PLEASE!

    by Back2-2 » Sat Dec 23, 2017 5:06 pm

    Good luck and please let us know what you find. Simple things first. ;)
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: Crf80 carb Help PLEASE!

    by Back2-2 » Sun Dec 24, 2017 11:15 am

    One big thing came to mind - Check your carb vent tubes to see that they are clear with no obstructions. That can wreak havoc on carb float level and cause the exact description you are having. Ran into that issue one time years ago and it drove me nearly crazy.
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200

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