four strokeing at mid throttle

Discussion in 'Norm's 2 stroke repair center' started by mike carter 2, May 28, 2017.

  1. mike carter 2

    mike carter 2 Member

    Nov 23, 2011
    Likes Received:
    hey yal,let me first tell about the 80 engine,reed valves,transfers port matched,ported piston,exaust and intake port matched,1979 suziki rm 60 chamber with fred c header.sill has stock jets in carb. all on a shwinn blackwell frame.the bike will do 40 + ,and gets there pretty quick.o yea,about 12 13 hundred hard miles on it.heres my problem,it has a hesatation around mid throttle.ive reset the needle more times than i have fingers,both up and down,the fuel mixture screw is set at about 3/4 turn out from bottom.thats where it runs best.any other fuel mix no good.the hesatation is worse when its cold.but almost clears up when warmed up. i just posted some pics on the high proformance thread . thanks
  2. Greg58

    Greg58 Well-Known Member

    May 1, 2011
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    Mike if it is running rich the spark plug should be dark color, it should be light brown on the porcelain. Have you made a test run without the air cleaner? If it runs better you need a smaller jet.

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