Help with rcgf 15cc
 

Hello again everyone, I need help with another engine. this one was bought new, set up on a test stand and ran fine, then set it up on the plane which is a 60 size mustang and seemed to run fine also, until the next day I decided to fire it up again and it ran for about 5 minutes got it tuned in just right and randomly died while at full throttle. After that it hasn't ran right since. It won't start half the time sometimes it will start and seem to run fine and I do some adjusting and seem to run ok and die and need to be adjusted next time it started. It's like I'm constantly adjusting it. Was messing with it this evening and thought I had it fixed till it dies and will only run a couple seconds when I restart.

Sounds like you have some tiny crap rolling around somewhere in the carb. It plugs an orifice (very tiny in this sized carb) then falls away at some time allowing short runs or non-starts. If the carb is a Walbro type pull the side inlet and check the screen for debris. Pull the needles and blow or supply gentle vacuum through the seats. Reset the needles to default and try again.

If it starts and runs continuously leave the dang needles alone for a while until a little run time gets some clean gas through it. If the engine is new, twiddling the needles right away can add to or be the issue.

If none of this helps a complete fuel system review and/or a complete carb teardown may be needed or return it to the vendor and let them deal with it.

Good luck.

Thanks I will check it out. I had the top and bottom covers off the carb with it on the plane and cleaned the screen, the other side I took off by mistake looking for the screen. I don't think I have it filtered well, I only have the sintered brass clunk, and one of those red dubro inline filters, idk if either is made for gas.

So are you saying to take the needle completly out, and blow through the holes they go in?

Also the guys at the field are always telling me to leave needles alone, I don't know if its a bad habbet or just trying to get it dialed in just right. I guess i may have to take it off the plane and work on it. Is it possible to buy a better carb for this motor? Will any walbro fit? I've heard these are cheap Chinese knockoffs of walbro

You don't mention changing the spark plug. It's an easy thing to do and although the plug looks good, it may be failing under compression. I've had it happen myself. Dan.

I havnt changed the plug yet, I have a dle 30 on the way can I trade parts around from that to see what the problem is? Obviously the plug would work but would the carb bolt up? Also as far as the timing, if it was running fine before, would it have messed up now? Engine has about 1/2 gallon through it now.

Here is "Milton's" video for checking timing. Dan.

As you haven't messed with the timing (yet), and it was running fine before, I think your trouble lies elsewhere.

If you are sure the ignition battery is fully charged, my bet is somewhere in the fuel system as well. If it's not plugged somewhere, there's a good chance it's sucking air through a loose fitting - or a fuel filter.

ihave a rcgf15 engine i had to chech the screen in the carb had somedirt in it cleaned it got a new fuel filter on my gas can and tank no more trouble

I have an rcgf15. It ran but not reliably. Later I bought a Bowman ring for another engine. With the ring he sent a blurb about the Chinese engines. He said to take the rear and reed valve apart and smooth up the mating surfaces. Then reseal every thing up tight on reassembly. I did that and it made a world of difference to my engine.

I don't know how to do all that, but I have faith in the motor it's just the carb I'm worried about. Would a dle carb or something bolt up to the motor?

If you have an air leak in the bottom end a new carb will not help.
Box it up and send it back to one of the distributors.

I only ask. Do you have a friend(s) with more gas engine experience? The 15 is usually reliable and easy to tune. It's a cooking engine and not fussy apart from getting adequate cooling. Set and forget. You may have a rogue ignition or some other problem, but if you know others who run gassers, they may easily identify and solve the issue for you.



1 1/4 turns out on each needle should run it albeit a bit lumpy.

A bad HT connection in the cap will be very unpredictable. Is it on tight, is the spring OK.

Check your supply battery. Test it under load. It may read 5+ volts but drop suddenly in use. Cycle charge it at at least 1A. Auto charging small 4.8V NiMh packs can be iffy!

Prop is 14*7 or similar? It isn't happy on larger props.

The reed valve is very simple and unlikely to cause trouble. It's a simple single flap.

Any Oil between 30 and 40:1 should be good.

I do have friends in the club but I'm always having problems with engines and asking for help. They all say I should quit buying planes and engines and fly the ones I have.

Anyway I'm running a 14x6 zinger also tried the rcgf 15x6 they seem to recommend for this engine but didn't help. A 6v battery fully charged and cycled which actually may be over 6v but I don't have a 4.8 to try. I'm using regular stihl oil for breakin. Personally idk if it would be all that as it was running great before.

I tried again today back at factory settings and it idles ok until I give throttle even slowly it dies I then began turning low needle until it ran at 5 turns, got the high where it needed to be and it seemed to run fine and transition for about 5 min and started spitting and sputtering like a dirt bike and died. After that it will not even begin to start so I gave it a rest.

If you need 5 turns on the low speed, you have issues. It's not right and needs to be dealt with properly. It's starved for fuel. Either because of an obstruction (anywhere from the clunk to the tiny internal passages in the carb), the inability to pump fuel (stiff or leaking diaphragm, blocked pulse port), or because it's sucking air (at one of the fittings anywhere from the clunk to the carb).

Start with the easy stuff first, and start eliminating potential problems. Eventually you'll find the one that's giving you the headache.

Your engine acts ex actually like mine did before I performed Frank Boemans instructions.
Maybe you have a friend than clean up that bottom end for you

Does anyone know if the dle 30 carb would bolt up to this?
Tower hobbud

Tower hobbies takes forever to ship, anyway if I put another carb on it and it fixed it, couldn't I just buy a new carb and be fine?

ypu seem to want to put a new carb on it.Go ahead-you dont need our permission

I have tried the carb for the DLE 20 and 30 on this engine and both fit. The needles are a bit sensitive with the 30 carb so I'd recommend the 20 carb. My RCGF 15 was a poor runner til I installed a Bowman ring. That made it a nice engine with decent power and would hand-start. The reed mod is always a good idea and a great learning experience. After doing it to one engine, I now carry out the same steps on all new engines or whenever I have the opportunity to remove an engine from an airframe when other work is required.

Hope this helps.

Thanx, not sure what about the Reed mod or bowman ring. Do you have a link to it? Also my brother came over yesterday he pretty good with small engines and things and took the whole carb apart and cleaned it

are there any american made gas engines if so try to buy american

CF Lee will convert one of his .60 engines for less than $200.You will have to supply the ignition.