I am still having problems getting a brand new G26 to work properly in the air. See the information below from an earlier thread. I readjusted the carb to lean out the low speed screw, it was running rich. In the air, the engine still wouldn't run right....it would lose power unless the plane was climbing. Below are some pictures of the installation and oil on the bottom of the plane. I have several questions:

1. The oil on the bottom of plane is from less than 10 minutes of run time. Since the mixture settings are about as lean as they can go, it would appear that the engine is richening in the air. What are your experiences with this?
2. The vent hole for the carb metering diaphragm is really exposed to the wind in this installation. Is the next step to put a deflector on in order to protect it from the wind?
3. The vent hole is on the right side of the picture. All the other pictures I have seen, the vent hole is on the top. Should this be rotated?


Any suggestions would be greatly appreciated!!!!





http://www.rcuniverse.com/forum/G26_...1885386/tm.htm
I'm having a problem with a new G26 on an Ultra Stick Lite. Both are brand new and flew for the first time today, however the engine didn't run good in the air. It loses power and actually died twice in the air. In level flight or descending it runs bad, climbing it picks up power. On the ground it runs like a champ. 7500rpm with a 16x10 prop and idles good. After the second dead stick landing, the fuel line was full of fuel without any air bubbles. The engine started on the third flip and ran like a champ again. There is the black oily "slim" on the bottom of the fuselage.

I did a search on RCU and am getting the impression that the engine may be running a little rich. Does this sound like the problem? If so, which screw do I adjust? The engine goes from idle to full throttle without any hesitation. Before doing the search, I tried richening up the high speed needle slightly, and it made the problem in the air worse. Also the rpm's dropped down a couple of hundred rpm on the ground. The velocity stack that came with the engine is installed.

Any comments would be appreciated.


6/8/2004 7:09:14 PM

Makes no difference which way the hole faces, it's for atmospheric pressure to operate the diaphragm...You could make a small plate to deflect air from the hole...A cover made from an aluminum can the size of the plate and spaced with washers under the screws works good...If it looses power except when climbing the high speed is too rich...

RCIGN,

I will try making the deflector tomorrow and see if it makes a difference. After I posted this question this morning, I went out and double checked the high speed needle to see if it was rich. About 1/8 of a turn in would cause the engine to lose rpm which is pretty much the same as the low speed needle.

I appreciate the suggestions.

Chuck

RCIGN,

I put a piece of aluminum over the cover for the carb diaphragm and that seemed to help. I then leaned out the carb a little and that helped a lot also. There is still a little black oil slim on the bottom of the fuselage, so I'm thinking of leaning it out the low speed a little more. The high speed is as lean as it can go without losing rpm. The transition from idle to full speed is still ok. I had a dead stick this evening after coming out a a large loop. I had backed the throttle down to idle and it just quit. Any comments or suggestions?

This is my first extended experience with a gas engine. The G26 is in a Ultra Stick Lite and at full throttle it doesn't sound all that powerful like a glow does, but the plane will climb out of sight in a vertical climb. I like it!

Chuck

The high should be set for max rpm, then opened up until it starts to slow down a little...
Some brands of oil make more black than others, the engines I run on my test stand have left little black spots on the door behind the stand..I run all different brands of oil, Klotz, Amsoil, Pennzoil, Dolmar, Poulan, whatever is handy...I always put more in than it should have...I LIKE extra oil....
The engine will idle at 15 or 1600 on the ground with a 17 or 18 inch prop, but when coming down from higher speed it probably loads up...Try not idling all the way down until the plane is on the runway....Look at the thread on the MVVS 160, lots of info on synthetic oil there...

to add- we have gone to "very high " oil concentrations -32-1 with as good or improved performance in all cases on pure synthetic..
No oily residue on bottom of model.
these are all synthetic oils - Klotz Model lube/ Redline Racing two stroke -etc..
Even using the plain ol Pennsoil two stroke air cooled - we get nice clean engines -BUT if you set the needles incorrectly - this will carbon badly .
It ain't whatcha got -it's the way that you use it --(old song)

RCIGN

Got Ultra Stick Lite back out again tonight and put on a 16x8 prop which brought the rpm up a 1000rpm. The engine now runs about 8500rpm and runs well in the the air. I then adjusted the high speed needle (about a 1/4 turn richer) which dropped the engine speed about 200rpm. In the air, the engine did not run well, lost power and ran rough at lower throttle settings. Leaning the engine back to give the max rpm made it more flyable, although it doesn't seem to develop as many rpm in the air as it does on the ground. Next time out I am going to lean the high speed just a little and see what happens. Maybe it is richening too much in the air. After that I will switch to Amsoil.

Chuck