Trips67

My Feedback: (1)

Hey guys,

I need a little help. I am new to the gas scene, and have a few questions. I have a H9 1/4 Cub with a G23 that I just boght from a fellow flyer that has only had 3 flights. I seemed to have it running well, it would idle and throttle up great. Then I would bring it back to idle, and then run it up and it would just slow down and die. I then decided to close both needle valves, and set them per the book. This seemed to take care of the problem, it was running great. I then flew it, and after landing I taxied over, and it did the same thing as before. i restarted it, and it was acting the same, it would just up and die on me. Any ideas.

Also do you have any prop recomendations?

Thanks,
Ryan

Wildmann

My Feedback: (3)

I fly miy Cub With a 16/8 master airskrew classic
It looks scale on the super cub
and it sounds like you have to adjust your high end needle
remeber gass engines are not like glow
adjust in small incraments
but it is mostlikely a mixture problem
another thing to look for is if the carb is loose I have seen that alot
esp with the new offset blocks
but once you figure it out Have lots of fun with that plane
I think I have about 175 flights on mine
and Its runs like a champ
wanna See it look at your new model aviation
in the Giant scale column
Mines 447 and is now a Camera
platform

Hangtime

My Feedback: (19)

what wildmann said.

plus give these items some thought..

dying out after a run-up would take me to the fuel system...

check the clunk and fuel tank stopper and pick up hose in the tank. you'd be surprised how many times i find glow-fuel hose and stoppers in gasser tank systems. (there was a recent run of mis-marked sullivan gas stoppers)

next, check for kinks.. wildmann can tell yah about kinks in cowl mounted fueler fittings.

possiblities abound regarding fuel mix and gas quality.. the lil zenoahs should NOT be run on hi-octane gas!! Gas/oil mix ratios and changes in oil brands/types can effect the settings. Also had a guy pull his hair out chasing a problem like yours only to discover his gas had a bit of condensation in it. Don't assume.. verify.

Check the base/turning block is not loose or split.. give it a wiggle. Check for fuel/oil tracking on the head behind and below the carb.

Last resort (after changing out fuel lines, tank stopper, replacing the fuel/oil mixture) is to pull the plate closest to the fuel inlet off the carb and inspect the internal filter screen. Maybe....

Good luck.. hope this helps!!

Trips67

My Feedback: (1)

Thanks Guys,

I will check these things out and hopefully find the culprit. The fuel I was using was fresh that day from mobil. No alcohol, regular(not high octane), mixed 32:1 with lawnboy ashless. Is this alright? Also after flying I had quite a bit of black residue on the bottom of the plane. Does this mean that is is rich on the high end? The flights thus far have been with cowl off, and fuel plumbed direct to carb, no fueler. How do you know if you have the right clunk in the tank? I will check it out because it was a plane I bought of a friend.

Thanks,
Ryan

Hangtime

My Feedback: (19)

Yup.

I've been told (and have observed) that the lil zenoah spews a lotta mung. That in itself does not indicate a 'rich' situation. It just indicates that the lil beast is running. If it's too rich it'll 'bog' on the top end; too lean and it'll stumble getting there.

I ran into a situation where there was no v-notch on the clunk, and the clunk as a result wound up pulling a vacuum because it rested squarely on the bottom of the tank. Another situation where there was a 'filter' incorporated in the clunk that was clogged. Another where the fuel tube was glow type and was being dissolved by the gas... and yet another where the clunk rested at the wrong end of the tank and sucked air.

If things don't look right, swap 'em out with 'known to be good' components.

Then there was the time the tank vent tube didn't vent anything because it was below the fuel level in the tank.... or the time I found the end of one smooshed against the top of the tank effectively plugging it.. and of course the all too frequent 'whoops.. plugged the vent hose into the carb inlet..'

Good luck.. lets us know how you make out!!

Wildmann

My Feedback: (3)

With the Gass engines I like to use the dupro heavy clunk
Just seams to work better with the tougher fuel line
and also the dupro fuel tank seal for gas engines ..
And Tygon only because I have a huge rolll of that stuff..
leave the cowl on just make sure you can adjust from the out side
(only an opinion but your engine should run withe the cowl on because thats the way it is going to be running all the time Adjust as you would run) wich is how we do things when I was building cars

pingber1

My Feedback: (10)

...anyone know what the proper mix is??? I use a packet of Amsoil .. that gives 100:1 .. the guys at the field thought I was crazy ...

Wildmann

My Feedback: (3)

Well What they recomend is a 32 to 1 ratio of regular oil I like Klotz super technoplate it works the best as far as I can tell. with over 500 runs on my 1st g23 and well over that on my 26 it loves it. Now as for your amzoil I would never ever run any 2 stroke at 100 to one I like an 80 to one mix for My DA 100.. And the recomend that for it..

NM2K

My Feedback: (14)

I run Amsoil at 100:1 with no problems, but I try to use some petroleum based oil at 32:1 for the first several gallons of fuel. No, I don't have any proof whatsoever that running petroleum at 32:1 provides any better performance or endurance. It just makes me feel better.

For the several utility engines that I have ran right from the start on 100:1 Amsoil, they are still going strong after many years of usage.

You shouldn't be seeing a lot of goop on the bottom of your model. There is nothing special or different about the G23 that would warrant such an accumulation. The fact that you are running 100:1 Amsoil should provide you with even less goop than normal.

Like the others have said, I would check the clunk, filters, etc. to ensure that nothing is amiss in those areas.

Just in case you aren't aware of it, you cannot use silicone fuel line with gasoline/oil fuel. The silicone will become flabby and will collapse during high demand (high vacuum) and will cut off the fuel to your engine.

Gas engines are not like glow engines in that you do not need to run them "rich", even when new, when compared to glow engines. A little bit rich for a gas engine is good, but not rich when compared to a glow engine.

Make sure that there is plenty of air inlet for cooling and then two to three times the area of the inlet for the warmed air exit. Overheating can cause a problem similar to what you have described.

The little G23 needs to rev up and should be ran with a 15x8 or a 16x6. Leave the 16x8 props for its bigger brother, the G26. Good luck.


Ed Cregger