They are the cheaper end of the market, but as so often happens crappy later versions produced, there always were probs with the orig linkage bar being poor or atleast the coupling...... but nothing that couldnt be overcome.....good power to economy gain over standard set up, as you hope from any twin set up, you have the benefit of short manifolds reducing the chance of the fuel dropping from suspension so a more economical burn more bangs for your bucks....spend a little time setting up the motor and you should be fine fella......