bogging down air leaks try this

Discussion in '2-Stroke Engines' started by rod, Jul 31, 2007.

  1. rod

    rod Guest

    my engine was bogging down so i replaced the inlet manifold gasket covering it all over with loctite no3 aviation non hardening form-a-gasket (great stuff)
    made no difference still bogging the problem for me was the other end of
    the inlet manifold tube is too short to push all the way into the carby
    (it hits the weld at the bend) so i ground some weld off and put a o-ring
    in the carby.
    i've seen a couple of posts on both these mods with pics check em out
    (full credit to these posts :) )
    what i added is a strip of aluminium can under the clamp on the carby
    i put a hole in it where the clamp locating lug is and made sure it was thight up against the shoulder and the joint was in the middle at the top took it off (after test fit)covered the inside of the strip with loctite aviation non hardening form-a-gasket put it on put the clamp on over it.
    then i cut 4 strips of thick gasket paper and covered them with form-a-gasket
    and pushed the strips into the slots in the end of the carby under the clamp and strip (cleaned the burrs out first) i then put a thin coat of form-a-gasket around the end of the inlet manifoldand inside the end of the carby put the o-ring in and pushed the carby on and held the pressure while i tightened the clamp now i have no more bogging down so it seems to work ok :)
    in the photo you can see the black of the strip i used under the carby clamp and a peice of the gasket strip hanging out the top slot on the
    opposite side of the carby.
    i made an earlier post that probably made no sense without a picture about fuel leaking from the carby (my pics were too big to upload then)
    in this picture you can see the fuel hose has an s bend if fuel starts running out an airpocket will form at the bend and fuel in the top half of the hose is trapped
    making this bend tighter and closer to the carby will trap more fuel
     

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  2. gone_fishin

    gone_fishin Guest

    that's too funny, another r & d enthusiast...i use that thin aluminum all over the engine:

    http://www.motoredbikes.com/showpost.php?p=61173&postcount=10

    http://www.motoredbikes.com/showpost.php?p=53307&postcount=1

    http://www.motoredbikes.com/showpost.php?p=68275&postcount=23

    2 things i have for you re: the fuel leak...

    1-you must get an inline filter on there immediately (see 2)
    2-your leak is (likely) the inlet needle being held open by debris (see 1)

    FOR EVERYONE: since we're displaying thumbs and opening images in a new window, i've been able to raise the maximum size of a .jpg to 1024 X 768 or 2M...this arrangement should make for more comfortable viewing overall.
     
  3. rod

    rod Guest

    fuel leaks

    yea i gotta get a filter on it i have one on my other bike cleaned out the
    fuel tank carby and reseated the needle on that one and it still leaks so the "s"
    bend is more of a patch than a cure i agree but it stops all the fuel in the hose leaking out
     
  4. gone_fishin

    gone_fishin Guest

    look around in here...details of the carby & more: http://www.motoredbikes.com/forumdisplay.php?f=88

    if it's dripping down steady, it has to be the needle/seat, another possibility is the stock air cleaner, it let a lot of carp through on mine...

    if it is debris causing the problem, you'll have to tear it all the way down and maybe blow-out the inlet, check float integrity & level, blah blah....you already know that part.

    keep us posted.
     
  5. ibeenjammin

    ibeenjammin Guest

    Hey Rod

    I am having the same problem. I just recently tried a smaller fuel line, but fuel still leaks from the fuel line to where it connects to the carb. I have had my entire carb ripped apart cleaned put back together, still leaks. Is there a fuel line that anyone recommends? I am all ears....thanks
     
  6. gone_fishin

    gone_fishin Guest

    take a pair of needle-nose and make sure the fitting itself is tight...just in case.
     
  7. rod

    rod Guest

    i thought the same thing about the fuel hose the hose that came with my motor went rock hard in a few days replaced it and still had leaks
    if you do thighten up the hose fitting on the carb the gasket will deform better to take out the gasket and use a non hardening sealant but if you do anything to the hose fitting you will need to reset your float the other end of the hose fitting is the seat for the needle valve so any change will change your float level

    but if the needle and seat valve has'nt sealed properly it could be coming out of the primer button hole there's no gasket at all in there and its the lowest opening on the carby or it could coming up through the jet and running out of the joint between the carby and manifold (longshot) everytime i noticed it leaking the fuel had already covered the top of the carby so i could'nt pin it down if your bike is doing it all the time clean of you carby get some beer sit down and wait for the leaking to start if you find it let me know
     
  8. gone_fishin

    gone_fishin Guest

    if it's coming out the "tickler" opening, then i agree it's a float-level or inlet needle-seat issue.

    these happy-time carby's are very sensitive to debris...an inline filter is a MUST-DO-NOW kinda thing.
     
  9. ibeenjammin

    ibeenjammin Guest

    I can see that mine is leaking where the hose fits over the fitting. I love having the clear tubing to be able to see the fuel situation, but all I have found is vinyl tubing which seems to eventually strech out and allows fuel to seep out. Am I the only one having this issue with these fuel lines? Has anyone found a fuel line that fits ultra snug around the carb fitting? I have already tightened the carb inlet and already taken the whole carb apart and had it thoroughly cleaned...no clogs...looked great. Every time I replace the fuel line it is leak free for about 2-3 days, then whahlah non-stop leaks. I am all ears.......
     
  10. azbill

    azbill Active Member

    are you using actual fuel line (impervious to gas)?
    if so, sounds like your line is a size to big
    I used the stock line on my big (3.3 gal) mustang tank and it was pulled off and replaced many times (I used it as a rolling gas station at the deathrace), and it still doesn't leak after switching my setup over to my current bike
     
  11. ibeenjammin

    ibeenjammin Guest

    I was using the fuel line that came with the motor, which looks like a fish tank pump tubing. which I believe is 1/4 in inner dia. I just recently bought the next size smaller, I was barely able to slip it on, which I finally though would work, but no dice. The only actual "fuel lines" that I have seen, are black. I love the idea of the clear tubing because I can see if the fuel is getting to the carby, but I may be forced to try the black "fuel Line" I was just hoping someone had some insight on a better clear fuel line that fits ultra snug on the brass fuel inlet on the carb.
     
  12. Kncool

    Kncool Guest

    so you say that the fuel line's end expands and gas leaks out, maybe you can try some small zip ties, 3 or 4 around the connection to the carb.
     
  13. rod

    rod Guest

    if you have a fuel filter on maybe you could use black rubber hose between the carby and fuel filter and clear between the fuel filter and tank you could also try
    permatex non hardening form-a-gasket on the hose and carby fitting it should make a seal around the bottom of the ball on the fitting. great stuff it won't be affected by the fuel
     
  14. azbill

    azbill Active Member

    have you tried a small hose-clamp?
    might be a $.25 fix
     
    Last edited: Aug 9, 2007
  15. ibeenjammin

    ibeenjammin Guest

    (see attachment) You mean something like this? This actually worked for a couple of weeks, then the fuel squeezed by again somehow....I seriously do not get it. I think I will try to do the black fuel line from the carb to the filter. The part I like to see though is the that there is fuel in the line from the filter to the carby. Oh well, maybe I will try the gasket sealer.
     

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  16. azbill

    azbill Active Member

    I actually meant a real hose clamp,
    it will tighten with even pressure all the way around
    it should be installed under the wide "barb",
    be carefull not to tighten so much as to cut the fuel line...
    as soon as you see rubber squeezing thru the little slots, it's tight enough
     
  17. ibeenjammin

    ibeenjammin Guest

    :eek: I didn't know that they made hose clamps that small. I will check Pep Boys later. Thanks for all the tips

    D
     
  18. skyl4rk

    skyl4rk Guest

    What size is the fuel line? 1/4"?
     
  19. drimpact

    drimpact Member

    Yup 1/4" I.D.
     
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