4 Stroke Carb- Fuel Filter and Adjustment? Noob

Discussion in '4-Stroke Engines' started by Htown, Jan 31, 2011.

  1. Htown

    Htown Member

    I had a flooding issues with the carb on my 4 stroke. I took the carb off and cleaned it thoroughly with some carb cleaner spray. There was some slight black (sludge) buildup near the bottom of the brass bowl and a tiny amount on the spring pin. I cleaned it up and put it back together including the petcock/filter in the tank. I have not gassed her up yet to see if the cleaning worked yet.

    Do you guys run an in-line filter as well as the filter that is on the backside of the petcock? I have a SBP filter I had ordered for another build I could use.

    After inspecting the carb I do not see how I could make it run more rich. Having replaced the air filter with a high flow version from SBP, the engine bogs when the choke is wide open. Though I have searched the forum I do not see any post that deals with re-jeting a 4-stroke carb, drilling or otherwise( plenty on 2-stroke). Is there some other adjustment I can make to the carb internally to make it run more rich, besides backing out the a/f screw?

  2. lemont1

    lemont1 Member

    Hey Htown,
    I had the same trouble not long ago, and could not find jets for the carb I have (HF 142 stock carb) so I got a set of fine bits from the hobby store and went up one size at a time. The mistake I made was to drill out both my carbs at the same time (two different bikes) allthough same motor, carb and air filter each one acts alittle different and required different size modification. Any way that seams to be the way to fix it short of replacing the carb with one you can actually get different jets for. As for the filter I cut out the one in the pepcock and use an in-line.
  3. Htown

    Htown Member

    Lemont1, thanks for all the info. Can you tell me exactly what you did to drill? Did you remove the jet and drill it on a bench? Do you remember which size bit you used for the two different bikes?
  4. lemont1

    lemont1 Member

    I can't recall the sizes I ended up with casue I am out of town and don't have the index but I just held the jet and spun the bit with my fingers (soft metal no drill needed). I took the jet to the local hardware/hobby store (ace in EL Segundo) and bought 8 bits $.99 each, started with the first one to fit snug and moved up from there. One bike took 4 try's the other I had to add some wire to reduce the hole size. I started a thread on this fourm looking for help a couple weeks ago and someone sugested that trick and it worked fine. The thread was "where to find jets for Huasheng 142 stock carb". Good luck with your bike!