Tips for trouble shooting my weak Ryobi 4 cycle

Discussion in 'General Questions' started by Nicad, Sep 12, 2015.

  1. Nicad

    Nicad New Member

    Just finished building my friction bike using a 31cc Ryobi 4 cycle engine and a 1.25" per drive. I was amazed how fast and powerful it was as I am 182 lbs. It is mounted on a touring bike with high pressure 27 inch rims. Pretty sure it went over 30MPH.briefly.

    I have put very few miles on the bike. Maybe 5. I had some fuel line issues and a couple of components fell off as they weren't locktighted. The last time it ran well was going down a hill. Now it has lost power. It will idle but die if I give it any gas even with the motor disengaged from the tire and spinning freely. I checked the air gap on the ignition module (I match book cover gap) checked valve clearance, checked cam timing, put my finger in the hole to test compression and have disassembled the carb and blown it out with compressed air, but did not remove the needles or jet.

    I will try to do a compression test with a gauge, but do not have the right fitting. My gut feeling says ignition or carb is clogged, but maybe I am missing something. The fuel tank is mounted slightly higher than the carb. It was fun while it lasted, and the motor was free. Just wondering , since I have quite a bit of time into my design, are there other motors that will match the Ryobi engine mounting pattern?

    ANyone have a trouble shooting tip?
    Last edited by a moderator: Dec 15, 2015

  2. 2old2learn

    2old2learn Member

    I suspect either an air leak or your carb needs to be thoroughly cleaned.
  3. Nicad

    Nicad New Member

    Thanks for the tip. WHen you say air leak, do you mean at the carb base? There is a rubber line coming out of the crank and I am assuming it helps pump oil up to the head. It is loose and I was considering replacing it.