Originally Posted by
Kenki
Thank you for your reply, I am running 20:1 Amsoil, but only octane 87 percent, and here in Cali, we have ethanol in our gas.
I am going to build a quick engine stand, and try to work out the issues.
Do you think the idle at half throttle has to do with the high end not being at peak?
Hello, Kenki, welcome to the thread.
I agree with others here that if the engine just quits running below half throttle then the low speed needle (LSN) is too lean. Turn it out a half turn and try again. Run the high speed needle (HSN) at 250-300 rpm rich of peak to compensate for prop unloading in the air. Once you have attained a suitable idle rpm work on leaning the LSN as far as possible at idle, this will stop your engine from hanging at high idle in the air due to prop unloading.
Amzoil has great products, I use their air filters, engine oil, gear lube and tranny fluid in all my autos and lawn equipment EXCEPT in my 2 strokes and 4 stroke model engines. Their 2 stroke engine oil has a known history of leaving higher levels of carbon deposits than other high end synthetic 2 stroke oils. Red line oil, Stihl Ultra oil and Castrol 2T are better choices IMO. I run Stihl in all my 2 strokes at 40:1 and in 4 strokes at 15:1. Please note that changing oil type or mix ratio will require retuning. Saito FG engines run fine on ethanolated 87 octane gas.
Also, be aware that gas has a much narrower combustable range than methanol, so once rough tuning has been accomplished fine tuning the needles requires VERY small changes, especially for the LSN.