Flyboy1958

My Feedback: (1)

I started my G26 and it started right up, boy does it run nice. I only have about 20oz. of gas through it right now. I have both needle valves open from closed at 1 and 1/4 turns. It idles at around 1,800 to 2,100 rpm and max is about 12,000 rpm., do those sound like good numbers? The part that bothers me and I guess I have to work on this is the mid range. It is a smooth transition from idle to about 8,000 or 9,000 rpm. then it flattens out for three or more clicks on the throttle, then picks up nicely. Is this correctable, like maybe a high speed needle setting or what? Just how should I tweek the needles from this point, or should I run a lot more fuel through it first?

tim220225

My Feedback: (4)

12000 RPM sounds high for a gas motor. What prop are you running? Maybe 8000 or so is ideal.

Flyboy1958

My Feedback: (1)

Master Airscrew Classic 18X6

tim220225

My Feedback: (4)

Cut this from Horizon,

G26 Air Engine (1.55 cu.in.)

Key Features

Large cylinder volume provides superior performance and power
Easy to start and adjust
Spins up to a staggering 8900 rpm on an APC 16 X 8 prop
Outperforms the G23 by 800 rpm and at only an extra 2 ounces

Sounds to me like the tach may be off as you are turning a larger prop. If you are turning that high it must be real lean. I have tried many props on my conversions and tried to wind them up tight. Had an Echo 23.6 over 10000 but the prop was a 15/6. Even put a bigger carb on it but it ran very lean and hot of course at that RPM.

Flyboy1958

My Feedback: (1)

That's what I was thinking. I have both needles at 1- 1/4 turns so maybe the high speed should be more like 1-1/2 turns out. What do you think?

blkbird68

My Feedback: (19)

I am turning 10100 on an 18x6 Skorepa with an RCIgnitions G26 on a home-made cannister muffler. Verified with 2 different tachs.

Flyboy1958

My Feedback: (1)

OK, high speed needle is 1-1/2 turns open and low speed is open slightly more than one turn. It starts and runs great but has a really crappy transition around 8 to 9,000 rpm. What should I do next?

RTK

My Feedback: (1)

I have used this procedure on all gas engines for initial tuning and it has never seemed to fail me.
I also have a g26 rcign1 conversion that turns a mejz 18x6 @9100+ on a fairly open exhaust.

Both needles out about 2 turns
#1 peak the high and back down 100-200 or use your ear
#2 keep leaning the low until it will not transition when goosed, then richen until it will
#3 re-peak the high and back down 100-200 or use your ear again.
Now fly and fine tune in the air if needed.

tim220225

My Feedback: (4)

The needles are close. Richening the high will slow it down but create other issues. I still think I would check the RPM with another tach. Test yours by holding it up to any light. Should read 3600 RPM all day long. If not then the tach is bad. 60 seconds per minute your house electric runs at 60hz or cycles per second. So 60 times 60 is 3600. If the tach is good with this test then change reading positions. Listen to the motor too. At 12000 RPM it should sound real tight and get hot too. Remember the engine is new so don't lean it too far.