ORIGINAL: marcelaw
Looking for help with a new uniflow setup on a boat. I'm running a Thunder Tiger Outlaw 7.5 boat, and have noticed leaning toward the end of my runs. In the constant pursuit of perfection, trying the uniflow setup.
Except for leaning toward the end of runs, boat was running pretty good on normal 2-line main tank, with 2oz hopper/header tank tied to muffler pressure. Setup the uniflow last night, and fired it up on stand. Once started, idle is more rough, and when giving it throttle has significant hesitation before RPMs jump up. I think I saw a post saying with uniflow you need to lean the low speed a bit...is that my issue? I'm not a tuning expert, but I would think the hesitation is caused by not enough fuel, so would need to richen low speed?? Thoughts?
Actually it sounds as if it is to rich on the low end now.
The hesitation is cause by it taking time to clear the unburnt fuel before it will spool up, I have had this happen many times as an engine gets broken in.
Your engine has an adjustment to vary the low end mixture it is called the idle adjustment lean it a bit then reset your high end.
You may have to go back and forth a few times till you get a smooth engine response at all throttle settings you might want to look in the glow engine threads for hints.
Did you install a check valve on the pressure line from the muffler?
The reason I ask is that if you did when you throttle back from high to low the check valve will cause the motor to load up (flood). If so remove it the worst case is you will spit some fuel into the muffler when you chop the throttle.