Engine running "R/ean?"

Discussion in 'DIY Home Built Motorized Bicycle (non kit)' started by TheSignGuy, Sep 30, 2017.

?

Which is more likely below?

  1. Worn intake to carb metal gasket.

    1 vote(s)
    100.0%
  2. Improper tuned base bowl needle.

    0 vote(s)
    0.0%
  1. TheSignGuy

    TheSignGuy Member

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    Hey so I got an issue so please be the tissue if you know anything about

    80s + Briggs & Stratton 3HP Flat heads/ L blocks looking for those type of users help.

    So I went on a 4 hour trip on a new plug ngk small engine plug and it runs fine....

    My last plug (home depot) shorty OEM Briggs plug was wet yet fouled out prior to this I had to remove my carb from the intake due to flooding caused by age and sitting for a week.


    Now after I changed the plug I have an issue with it running lean/hot according to the plug.

    It's ashy white but comes off by just a wipe of the finger.

    (Do you think my metal carb intake gaskets worn out?


    Some times idles down as if it's going to stall then sometimes it will idle up.


    Frequently according to the exhaust it smells rich other times it has no smell at all.



    Comment below and answer the pole thanks.


    Here's 6 minutes of my 4 hour ride closer toward the end of the ride day.

    Please omit the chirp sound it is "not a part of the engine." The clutch needs a rubber washer between the main bolt and clutch."

     
    #1 TheSignGuy, Sep 30, 2017
    Last edited: Sep 30, 2017
  2. Ludwig II

    Ludwig II Well-Known Member

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    What grade is the plug, does it need to be replaced with a colder plug? I'd replace the gasket as a matter of course, and also suggest the use of a fuel resistant sealing past smeared on the flat faces as well.
     
  3. curtisfox

    curtisfox Active Member

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    Also make sure the surface is good and clean before gasket install...........Curt
     
  4. curtisfox

    curtisfox Active Member

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    You may want to check the oil for gas smell, if it was flooded like you say it might have oil in it, and need to change. The old Briggs like straight 30 weight the best...........Curt
     
  5. TheSignGuy

    TheSignGuy Member

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    Not really sure but I know the stock plugs fairly cold ngk sells typically hot plugs here's some info I can provide the current plug is a NGK BMR6A

    BRIGGS BS-SV-CU 992300C

    ALSO IT RAN A TINY BIT LESS HOT...


    the gasket is how ever in pretty fair condition for its age, little light sandpaper would help on one of the surface sides


    What sealant should I use shellac?
     
  6. TheSignGuy

    TheSignGuy Member

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    Intended on changing the oil today to royal purple

    The oil that's in it now is dollar store synthetic smb 10w-30 just wife testes with a small hose and nostril wiff doesn't smell like gas just lightly worn car oil.

    The motor does not smoke however.
     
    #6 TheSignGuy, Oct 1, 2017
    Last edited: Oct 1, 2017
  7. Ludwig II

    Ludwig II Well-Known Member

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    In the past I have seen manifolds where there was a hairline crack that leaned the mixture out. Have you checked the area around the flange where it bolts to the head?
     
  8. TheSignGuy

    TheSignGuy Member

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    I'll check it now but I doubt it's cracked if it is we should start talking about governor deletes and kethin careb updates at this point..

    If dishing out $30-$40 for an intake may as well upgrade to a proper throttle cable set up and upgrading the flywheel for weight reduction/starter add-on.
    At this point I see no cracks.
     
  9. curtisfox

    curtisfox Active Member

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    Cable yes, flywheel not yet. Wait till you get barking good first, and a few hours on it, then if it all works out go for it........Curt
     
  10. TheSignGuy

    TheSignGuy Member

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    1506893191142775359056.jpg
    OK maybe it's me but OK we discussed the bowl needle jet before in is lean out is rich right?
     
  11. curtisfox

    curtisfox Active Member

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    You got it, Them are good carbs and you can still get kits for them. Top right is air mixture screw..........Curt
     
  12. TheSignGuy

    TheSignGuy Member

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    Oh never touched that one always used the bottom what's the bottom one my fingers pointing to for?


    Also found a solution for the alignment issue.
     
  13. curtisfox

    curtisfox Active Member

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    That is the mixture screw for rich or lean, air screw is for. If it bogs or hesitates when you crack the throttle, need to adjust the air screw........Curt
     
  14. TheSignGuy

    TheSignGuy Member

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    Doesn't bog or hesitate issues primarily relative to richness.. I did notice if I do a cooled piston warm/hot body start it's faster until fully hot...

    In is lean out is rich right? From my base setting it's about 11 turns in for proper settings.
     
  15. curtisfox

    curtisfox Active Member

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    Out is rich, should be about a turn and a half. Best way is to somehow hold throttle open some ( don't have to be all the way, just above idle some. Turn mixture screw till you get highest rpm, then richen it about about 1/4 turn..................Curt
     
  16. TheSignGuy

    TheSignGuy Member

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    So the base lines correct then.... I usually stick 1 to 1-1/2 a turn s think I may have an idle issue I'll check it out Tuesday have to drive to a doc appointment plus I work today which is Monday.
    Good thing it's easy to drop the belt between half throttle for 5 minutes is recommended and I still need a double kick stand.
     

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