Well i couldn't resist the cheap lanier explorer 40 trainer at tower hobbies for $49.99, my OS 40LA looked way to small in the engine bay of this plane so i mounted my 21cc weedeater engine, CG is good and the total weight of the plane is only 10oz more then with a .40 sized engine, do you think a plane like this will handle this engine? My bench tests show that it makes the same power as my TT PRO.46 and the 21cc engine only weighs 32oz and will mount tight to the firewall with 4 bolts and some rubber insulation in between the engine plate and firewall.

If the CG is good give it a spin and let us know how it went. Good luck
" A bumble bee is considerably faster than a John Deere Tractor "

Ken

4 oz tank should give ya about 30 mins flight time,ya think.

Well she flies, for a minute anyways, now i'm not quite sure why it deadsticked twice in a row but i think i read something about venting that hole in the carb to the inside of the plane or somewhere out of the prop blast. I had to flip the carb so now that hole is in the prop blast, could this be causing the dead sticks, it runs fine on the ground.

Here is the maiden voyage http://www.rcuvideos.com/item/JL03MHZ3DMYHLR02

You do have a velocity stack on it I notice which helps with the prop wash situation, but I think I would try one without the angle cut on it, which I think would be better for air flow. With an angle stack the air doesnt have enough time to straighten out which I think is causing your problems.

Terrell

Well i will try it without the velocity stack tomorrow, but it's more about that little hole on the bottom of the carb that is supposed to vent to the atmosphere and i swore i read it somewhere on here that if it is in the prop blast it will cause the problems i'm having, i will have to search for it.

Yeah, it's not good to have that hole in the regulator cover pointed into the prop blast. I usually solder a brass tube into the hole and then route a hose to an area of undisturbed, non-pressurized air.

AV8TOR

That is exactly what I have been told too, and I try to keep the carb with the hole to the rear. However I have a Homey 30cc and a CRRC 45cc both with the hole "in the wind " with out a problem. Some seem to some dont, who knows.

I tap the hole and put an pressure tap from a large Super Tigre in it.

It sounded to me like you ran out of gas or spark.

It didn't start running bad, it just quit running.

Did it start right up when you tried it again?

I had a felt clunk that looked clean but didn't allow the engine to run right.
I replaced it with a small length of brass tubing for the clunk and the problem was solved.

The plane seemed to run and fly very well, when the plane ran it was good.

May I also add that was a nice save there at the end.

Keep us posted

Your cameraman is hilarious.

"Don't hit us. Oh *&^%$ Where ya goin' ?"

I haven't laughed like that in a few weeks. [sm=thumbs_up.gif]

Sounds to me like it got hot.Im converting a 22cc echo[21.2actual] and starting out with an APC15x8.If the 3 blade your running is any smaller than a 12 inch i bet your rpms are to high.Richen both needles up some and try again.I would also put a nippel on carb cover and run a line behind the engine and attach to firewall.But i would try prop and needles first.If ya have to lengthen the gear for better prop clearance or move the main gear forward some,use longer mains,put a tail wheel on it,make it look like a Storch!

I'm running a MA 13x8 3 blade prop, i solder on a brass pipe on the regulator cover and routed it to the inside of the fuse, it did the same thing today but when i went to unfuel the plane it would not come out so i think i better pull the tank out and see what's going on. Now i think the vent line was plugged on the tank on the test bench but it is open now, should this line be plugged? Also i haven't put a muffler on yet, would the lack of backpressure be part of the problem ?

Still dead sticked after a few minutes of flight with regulator cover hole routed to the planes fuse. We think we may have found clunk problem, but ran out of time to check. But here’s another video with a little bit nicer landing.


http://www.rcuvideos.com/item/NC15PK2H3S7F926J

Your tank vent must be open. Also, don't hook it to the muffler. It is dangerous to do so, and it is not necessary as the carb has a built in fuel pump.

AV8TOR

A lot of times even Tygon tubing will swell slightly when exposed to gasoline. You need to wrap some wire around each connection to make sure they don't get loose and either suck air or come apart. Your clunk may have fallen off the pickup tube in the tank. A friend of mine had a problem like this, and we discovered the whole pickup line and clunk had fallen off the tube in the tank. I use fuel barbs and safety wire on all my hose connections.

You did change your tank stopper and lines to gas compatible right??

AV8TOR

Yes i did change the stopper to a gas compatible one ( dubro tank ). I used Hayes neoprene line on the inside of the tank, is that ok or should i use tygon?

av8tor do you think having no muffler on could be part of the problem as yesterday the fuel system was fine ( other than the hole in the regulator )

Neoprene inside the tank is very good, there is no need to use a muffler other than your hearing.

No muffler may of caused it to lean out at top end.

No muffler at all on a glow engine will also hurt the idle performance.

I don't know, but I just get this feeling you are running lean for one reason or another, and that is why it's quitting. Are you throttling back and it's quitting, or is it quitting at full throttle? Try richening up the high speed needle and see what happens. If you can't get it to go over-rich when turning the high speed needle out, you will need to raise the lever in the regulator just a touch. It usually works out for me on Gas/Glow engines if the bottom of that metering lever is even with the carb casting, which is just a touch higher than normal spec.

Also, the FIRST thing I check on these engines when they start giving trouble is the regulator diaphragm. They have to be extremely supple, and not distorted. They often dry out and get stiff, and then the engine won't run right, or sometimes at all.

AV8TOR

Well the clunk and tube inside the tank were not attached anymore, that explains the quitting on the second day. Since this engine is about 3 times the displacement as needed i can pretty much fly around at a high idle throttle setting to keep her in the air, i will try to get the muffler done for the next time up and see if all goes well. Thanks for the help.

Well i put a muffler on it, got it to run good on the ground but it deadsticked twice on saturday, second one was the end of this test, i missed by about 20' and stuffed it in hard, ripped the engine off and the wing had some minor injury. I think the carb probably needed a rebuild as it was 11 years old and i don't think the pump was working 100%, oh well Monster46 got himself a new trainer ( i hate fixing and it was his birthday ), and the engine sustaned some damage so that's probably the end of the 21cc but Monster46 just gave me a ryobi 31cc to play with, it is much newer than my 21cc but it has a zama carb, any Walbro #'s to replace this ?

Thanks with all your help on the GAS/GLOW setup and i look forward to getting the 31cc running better than my 21cc

Ah Wayne!

I was wondering who you were. Sorry to hear about your plane

Sent you the addy but someone else put it on the thread anyway.

Rich

Sorry to hear about your plane. But yeah, wow, an 11 year old carb would definitely need a rebuild before one could expect it to work well. The regulator diaphragm needs to be very supple to work well. I have seen diaphragms from gas engines be too stiff to work properly after a year or less. It depends on the fuel used, etc., but it is a good item to check thoroughly any time you have problems with one of these gasser engines.

AV8TOR