1993 CT 70 gas leaking from carb vent tube

PlanetMinis Forums

1993 CT 70 gas leaking from carb vent tube

This is a discussion on 1993 CT 70 gas leaking from carb vent tube within the Z50, CT70 and JDM Monkeybikes forums, part of the General Talk category; Please help. The last time I messed with the carb, it was running horrible and flooding so on the advice I sought from here, I ...

Page 1 of 2 12 LastLast
Results 1 to 15 of 18
  1. #1
    Senior Member
    This user has no status.
     
    Expygator's Avatar

    Join Date
    Jun 2012
    Location
    Nashville, TN. (Smyrna)
    Posts
    154

    1993 CT 70 gas leaking from carb vent tube

    Please help.

    The last time I messed with the carb, it was running horrible and flooding so on the advice I sought from here, I bent the tab on the float of my non- adjustable carb. This fixed the flooding issue ( I thought) but as it turned out, I had re-installed the barrel in the carb backward which caused the flooding. Anyhow, bending the tab would have worked had I not installed barrel backward. Now it has caused it to run out of gas and the bowl would run dry.


    I just cleaned my carb because I haven't ridden it in a year. In addition, I bent the tab on the float back in the other direction. Now it runs great ( and I haven't tuned it yet) but gas is pouring out of the bottom vent tube on the carb bowl. WTH? What can I do? I have the tube plugged with a golf tee.

    Did I do something wrong?

    Dean
    Last edited by Expygator; 05-13-2017 at 06:09 PM.
    Hidden Content
    1993 CT70, stock...919 miles

  2. #2
    Super Moderator
    is grateful again...
     
    dirtbkr188's Avatar
    Supporting Member

    Join Date
    May 2004
    Location
    New Jersey
    Posts
    8,250
    Often times, when a bike sits for a long period of time, the float needle (shown below) will get stuck in the seat, and allows fuel to flow (and overflow) in the float bowl, and out the bowl drain. If you removed the float needle to clean the carb, possibly there still may be something in the seat, preventing the float needle from closing all the way. You may also have "over-corrected" when rebending the float tab, and now the needle isn't closing al the way in the seat.

    - dirtbkr188 -



  3. #3
    Senior Member
    This user has no status.
     
    Expygator's Avatar

    Join Date
    Jun 2012
    Location
    Nashville, TN. (Smyrna)
    Posts
    154
    Good theory. I did in fact remove the float needle. And I agree that I must have over corrected the tab bend because besides that, I'm at a loss.

    I'll give it a shot.

    Thanks.
    Hidden Content
    1993 CT70, stock...919 miles

  4. Remove Advertisements
    PlanetMinis.com
    Advertisements
     

  5. #4
    Super Moderator
    is grateful again...
     
    dirtbkr188's Avatar
    Supporting Member

    Join Date
    May 2004
    Location
    New Jersey
    Posts
    8,250
    Do you shut the petcock off after every ride?
    - dirtbkr188 -



  6. #5
    Senior Member
    This user has no status.
     
    Expygator's Avatar

    Join Date
    Jun 2012
    Location
    Nashville, TN. (Smyrna)
    Posts
    154
    Yes I do now. There was a time when I didn't so I checked the oil and it smelled really gassy, so I just went out and started it up, got the oil warm and let the carb run dry and run out of gas. I drained the oil and put some new 10W-30 and some straight 40 wt. that I had sitting around , just to run it after I get the carb sorted. Then I'll change it again to make sure the gas is all flushed out of the crank case and then put my Honda oil int it.
    Hidden Content
    1993 CT70, stock...919 miles

  7. #6
    Senior Member
    This user has no status.
     
    kirrbby's Avatar

    Join Date
    Aug 2014
    Location
    Davison Mi.
    Posts
    431
    Regular car oil is going to ruin your clutch fiber discs. You HAVE to use the proper oil.

  8. #7
    Senior Member
    This user has no status.
     
    Expygator's Avatar

    Join Date
    Jun 2012
    Location
    Nashville, TN. (Smyrna)
    Posts
    154
    Quote Originally Posted by kirrbby View Post
    Regular car oil is going to ruin your clutch fiber discs. You HAVE to use the proper oil.
    I have never used regular oil, and won't ride it with that oil. I'm only going to start it, let the oil circulate to clean out the gas and drain it again and put my Honda 20W-50 in.
    Hidden Content
    1993 CT70, stock...919 miles

  9. #8
    Senior Member
    This user has no status.
     
    Expygator's Avatar

    Join Date
    Jun 2012
    Location
    Nashville, TN. (Smyrna)
    Posts
    154
    I have bent the float tab back the other way. It is not leaking gas through the bowl vent tube. I gapped my standard plug to .025. I will change the plug to the one for high rpm operation for extended periods since that is what I'll be doing with the bike. It is going to be street driven in Nashville. I changed the oil and put Honda 20W-50 in it. Ill run this for a few miles until I get the carb /idle/ air screw set.

    Incidentally, I took apart my air cleaner assy to inspect and clean, but it was fine. However, in the process, I discovered that there are three tubes that feed air to the air box, but one of them had a plug in it. I removed it of course and now have a potential to increase air flow by 33%.

    What is the quick and dirty rule for setting the idle and then the adjusting the air screw?

    Dean
    Hidden Content
    1993 CT70, stock...919 miles

  10. #9
    Super Moderator
    is grateful again...
     
    dirtbkr188's Avatar
    Supporting Member

    Join Date
    May 2004
    Location
    New Jersey
    Posts
    8,250
    I would start the bike and see how it idles and then runs with the extra air input. If it dies when you start it, hold the throttle a tad, and turn the air screw in to get it to idle, and then ride it and see if you'll need to adjust the air screw IN to richen it. Basically, it's a trial and error method IMO, it just takes a few minutes of your time to find that fine line.
    Last edited by dirtbkr188; 05-15-2017 at 04:04 PM.
    - dirtbkr188 -



  11. #10
    Senior Member
    This user has no status.
     
    Expygator's Avatar

    Join Date
    Jun 2012
    Location
    Nashville, TN. (Smyrna)
    Posts
    154
    I've ridden it and now I'm out of gas. I set the idle at 1700 - 1800rpms. However, I need to ride it longer so that it warms up enough for the rpms to level off, then I can recheck the idle. Air screw is IN for more and OUT for less. Got it.I'll get some gas and a new plug tomorrow and give it a go with the idle and air/fuel. I can hear it pulling additional air. In FL the bike would run flat out with me tucked and wearing a helmet, 46 mph on gps. I've gained 20 lbs and I'm in TN. At least one of those will make a difference. I'd love to be back at 45-46, but there are so many hills here that it's hard to do it.


    Thanks!!
    Hidden Content
    1993 CT70, stock...919 miles

  12. #11
    Senior Member
    This user has no status.
     
    Expygator's Avatar

    Join Date
    Jun 2012
    Location
    Nashville, TN. (Smyrna)
    Posts
    154
    Quote Originally Posted by dirtbkr188 View Post
    I would start the bike and see how it idles and then runs with the extra air input. If it dies when you start it, hold the throttle a tad, and turn the air screw in to get it to idle, and then ride it and see if you'll need to adjust the air screw IN to richen it. Basically, it's a trial and error method IMO, it just takes a few minutes of your time to find that fine line.
    I have the bike warmed up and the idle is set at 1700 +/-. I'm riding around and it rides fine. I started with the air screw 2 full turns out. As its idling, there is some smoke very faintly coming from the exhaust. It seems more blue in nature than black. Is that an all together different issue?

    Dean
    Hidden Content
    1993 CT70, stock...919 miles

  13. #12
    Super Moderator
    is grateful again...
     
    dirtbkr188's Avatar
    Supporting Member

    Join Date
    May 2004
    Location
    New Jersey
    Posts
    8,250
    It might need valve seals, have you ever done anything to the head since you've owned the bike?
    - dirtbkr188 -



  14. #13
    Senior Member
    This user has no status.
     
    Expygator's Avatar

    Join Date
    Jun 2012
    Location
    Nashville, TN. (Smyrna)
    Posts
    154
    Quote Originally Posted by dirtbkr188 View Post
    It might need valve seals, have you ever done anything to the head since you've owned the bike?
    No I have not, and it's never had the valve clearance checked nor the oil skimmer cleaned. I'm at 900 miles.
    Last edited by Expygator; 05-16-2017 at 11:12 PM.
    Hidden Content
    1993 CT70, stock...919 miles

  15. #14
    Super Moderator
    is grateful again...
     
    dirtbkr188's Avatar
    Supporting Member

    Join Date
    May 2004
    Location
    New Jersey
    Posts
    8,250
    If the bike kicks over and fires up with only a few kicks, chances are your valves are within spec, but if you want to do an adjustment, try .002" for the intake and .003" for the exhaust.
    - dirtbkr188 -



  16. #15
    Senior Member
    This user has no status.
     
    Expygator's Avatar

    Join Date
    Jun 2012
    Location
    Nashville, TN. (Smyrna)
    Posts
    154
    The bike starts on the first kick. As for the valve adjustment, I'll have to refer to you tube as I have never done this before. I don't even own a feeler gauge. I'm guessing that's what you use.

    I think that riding the bike will help with just getting the carbon blown out, and a couple of more oil changes should get the crank case cleaned up a bit. I'll take it a few miles down the road this weekend and hopefully I can get the air/fuel sorted. I have my new plug, but really don't want to install it until it's running clean.I guess I can also try to tune it by the plug color. I'm pretty sure that I'm 2 1/2 to 3 turns out on the air screw.

    By the way, am I supposed to have an in-line fuel filter because I do not have one?

    Dean
    Last edited by Expygator; 05-16-2017 at 11:29 PM.
    Hidden Content
    1993 CT70, stock...919 miles

Page 1 of 2 12 LastLast

Sponsored Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Similar Threads

  1. Outlaw billet klx110 gas cap & vent tube 02-09
    By Imback in forum KLX110/Midsize Parts for Sale
    Replies: 4
    Last Post: 05-26-2016, 08:27 PM
  2. WTB: KLX 110 Stock Gas Cap and Vent Tube
    By yamaha600racer in forum Bikes and Parts Wanted - All Makes
    Replies: 1
    Last Post: 01-03-2011, 03:55 PM
  3. WTB: OEM Plastic Gas Cap w/vent Tube for KLX110
    By klx1tenL in forum Bikes and Parts Wanted - All Makes
    Replies: 2
    Last Post: 02-01-2010, 09:32 PM
  4. Need a gas tank vent tube
    By patman in forum CRF50/CRF70 Parts For Sale
    Replies: 1
    Last Post: 10-28-2006, 12:55 PM
  5. gas wont stop leaking out of the over flow tube...
    By VanillaGorilla in forum CRF50
    Replies: 13
    Last Post: 02-14-2005, 05:44 AM

» Log in

User Name:

Password:

Not a member yet?
Register Now!

» Sponsored Links

Powered by vBadvanced CMPS v4.3.0