Engine tuning question??
 

I am having trouble with my dad's engine, it starts and idles fine but when you run it slowly up to WOT it will run fine for a couple of seconds and then start to die out. When you quickly try to rev it up it dies. I have checked all my lines to make sure that there are no cracks in them that would lead to leaning out. Does this sound like a low speed setting problem. The engine is an Evolution .40NT. I have adjusted the high speed needle all over the place and it doesn't seem to make a difference in what i described above.
Flyoby76

RE: Engine tuning question??
 

if you cannnot get it to run rich with the highspeed needle try opening the low speed needle about 2 turns.how many turns open is the high speed needle at least 3?

RE: Engine tuning question??
 

It is only open one full turn right now. And it pukes fuel out when running full throttle.

flyboy76

RE: Engine tuning question??
 

when at full throttle exactly where is the fuel coming from,the front bearing area,one of the tank vents out the muffler?

RE: Engine tuning question??
 

sorry it comes out the muffler. It looks to me like it is running rich but it doesn't matter how much i lean it up it still has these characteristics

flyboy76

RE: Engine tuning question??
 

Open the carb barrel 1mm

Close the low-end needle, then re-open it 1 1/5 (One and one fifth) turns.

That is the proper starting point for the low end

RE: Engine tuning question??
 

I will give that a try and let you know. It may be a couple of days as i will be out of town.

Flyboy76

RE: Engine tuning question??
 

Let it idle for 10 seconds.... Then when you quickly go from low throttle to high throttle and the engine speeds up and dies, the "low speed needle" is too lean. If it sputters, hesitates, and dies, the "low speed needle" is too rich.