flyitrite

Hello all, I installed the 10cc in an Escapade Mx and have been running it in the last few days. I was wondering about the carb regulator, is it a demand type? I have not disassembled it to examine it yet but after running it today I thought I would blow air into the vent line to check for leaks. I noticed that the air would escape through the carb without the engine running. I assumed it would close unless the engine was pulling fuel.

ahicks

My Feedback: (2)

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Interesting....

I have 2 of these, the second of which I just started flying. Due to habits learned running the bigger (pumped) gassers, I generally do not drain the fuel from the tank after a flying session. The last session ended shortly after topping the tank off, and the engine is mounted inverted, putting the carb significantly below the fuel level in the tank. This resulted in fuel slowly dripping from the carb throat onto the bench...

The first engine is mounted horizontal, and I haven't seen that one do this - leading me to wonder if this was a "normal" feature of this system as well.

The regulator is designed to regulate fuel pressure. I don't know if this includes a shut off when the engine isn't running? Thinking if that were the case though, it might be difficult to start the engine? You'll need to have fuel available to do that, and if it's shut off?

flyitrite

I was thinking along the line of something like a Cline regulator or perhaps how the YS fz series work. These types only allow fuel to pass if there is a demand ( pull from the engine) and permit tank placement just about anywhere. I have read in here that the tank placement DOES matter somewhat with this engine. Wow that muffler is terrible on this thing. I stopped the leak at the engine by using some gaskets I ordered online but the tube still leaks and is as tight as possible. There is a bad vibration in the middle throttle setting on these engines as well, It cracked the cheeks when I installed the first one on an Avistar Elite earlier this year ( everything is super balanced). Have you noticed the middle rpm vibrations?

ahicks

My Feedback: (2)

The shaking is something I've learned to try and just ignore when running bigger gassers. This second engine is in a .46 size U-Can-Do, and there's a resonance going on (wing maybe?) I'm not sure I'm going to like in the long term. First engine was in a Yak, and I noticed no unusual vibration there. Now it's in a Phoenix Decathlon, and it's got nothing going on.

So, still learning. Not knowing any better, it is what it is?

Regarding the fuel drip, maybe I'll pull that carb down to see if I can find some dirt in it. -Al

JoeyCoates

I have not noticed any unusual vibrations on mine (also in Phoenix dacathlon) but I only have about 6-7 tanks through it. I just switched from a 11x6 xoar to a 12x6 APC though and did not notice much improvement in the vertices and it seems I lost a bit of speed. I might try a 12x6 xoar next, those APC props are heavy. I have started to lean it out a bit and it is starting to run smoother with less 4 cycling although I feel it still has some running in to do. The vertical is ok, but still somewhat limited compared to most of what I fly. With that being said I do like the engine, it goes for a long time on 11oz of fuel, easily 25 minutes. The black goop it had on first 4 tanks is already subsiding some and I think it will continue to get cleaner with more break in.

Before I even ran mine I sealed the muffler sections with grey rtv engine sealer and it is holding up quite well.

ahicks

My Feedback: (2)

Limited vertical- yup! Decathlon is 7lbs, about as heavy as I'd consider for this engine and my performance expectations.....

I might try a 13x4.

flyinwalenda

My Feedback: (5)

Over 3 gallons burned and have been running a 13x6 on the Meridian (7.8 lbs ) and it hauls it around very nice.

flyitrite

The plane I have this one on comes in at 5lb 2oz . It had good vertical with the 10x6 MA. Now it has a 12x6 MA and is powerful. I am using a 4oz tank, Tech aero ibec, 700mah life battery. Lots of fuel after my short 5-6 min flights so far. All the vibration is in the middle of both of these engines I have run, If I slowly transition the throttle it starts about half, maybe 60% open and mostly goes away at full throttle. Hoping to find out more about the regulator type and why some fuel always passes even when it's not running . I asked the HH rep on here so will see.

jspauld2

In reply to the regulator question, it basically just ensures that there is a little more consistency to the fuel flow/pressure than normal. It is not an effective pump, but it has some pumping action that helps store a small amount of fuel near the carburetor for when the engine needs it.

Hope that helps.
Jimmy

ahicks

My Feedback: (2)

Was flying the engine I have that's dripping fuel from the carb throat when the fuel level is above that of the carb again today. I'm using a 3 line system on the fuel tank. While filling the tank, I'm watching for fuel to come from the muffler pressure line. As the tank filled and fuel came out the pressure line, it also poured from the carb!

I'm thinking there's trouble in paradise. Going to pull that carb down for sure now. Anyone have enough knowledge of this carb where they might have me looking for something "special" going on?

BTW, the engine seems to be running fine. Good idle, transition, and though not completely broken in, seems to be making good power. -Al

jspauld2

Al,

Why are you pulling the carb? From the sounds of it, the carburetor is working perfectly fine. The way your engine/fuel tank is set up it just siphons fuel for a moment while fueling. There is nothing wrong with that from the carbs perspective, there are no one way valves in the regulator. If you don't like it, you could always pinch off the carb fuel line with a pair of forceps.

Thanks,
Jimmy

ahicks

My Feedback: (2)

Well, I guess that's what I was wondering about?

So if I need to pinch that line during fueling to prevent that "squirt" as the tank becomes filled -
what I'm understanding is we're calling for the tank to be mounted in a manner that centers it on the carb. With a full tank of fuel, this puts half of the fuel above the spray bar, right?

So fuel dripping from the carb when it's just sitting there with a full tank is normal?

If that's the case, thinking future installs will have me installing the tank so the top of it is at the spray bar. That concept could also provide motivation to look into a "pumper" style carb as well.

-Al

flyinwalenda

My Feedback: (5)

I've never had fuel forced out of the carb. The fuel should take the path of least resistance to exit the tank when most of the air is gone and that should be the open line to the muffler(the same one where air is pushed out). If the muffler line is closed or restricted then it will come back down the carb line. Something is wrong somewhere in the plumbing.

ahicks

My Feedback: (2)

The plumbing is a standard 3 line system.

1 vent
1 line from felt clunk to carb
1 line to 2nd clunk, used to fill/empty tank, plugged when not in use.

This system of plumbing has been working fine for the last hundred years I've been flying, gas and glow. The plumbing is fine.
Further, I have another plane with this same engine, plumbed identically, that doesn't exhibit this issue. The only difference there is that engine is mounted on it's side.

flyitrite

Ran the engine more today, about a half gallon total through it so far. This is the 2nd one of these 10cc's I have used and at this point I think I can say they are indeed good engines. I have also decided that the muffler is not bad.... it's atrocious. RTV stopped the extension leak, but the bolt still leaks at the front. It is a very small leak now so I will continue to break it in and try other props. An APC 12x5 was the order of the day today and it was good but not what I guessed it should be. I plan to try an APC 11x6 and an EVO 12x8 tomorrow. Spent an hour + balancing that 12x8 . Bought a GP spinner ( too heavy ) and then a TT (still too heavy) for the little plane's CG. Where do you all have your low speed needle???? I find that I am way in from the suggested and still not a smooth transition. This is a fun project so far.

flyitrite

Nothing? Still wondering where everyone has their needles at. Hope to try Macs pipe this weekend with the 12x8 Evo prop. Anybody have numbers for that? I am getting 95 to 96k. This is a great engine on the new Escapade.

ahicks

My Feedback: (2)

After wandering around trying to set the carb up the way I'm used to, and failing miserably, I went with the suggested low speed setting, then set the HS for a little rich of peak and flew it. Engine is still low time, so I'm not pushing anything. At half throttle and level cruise, it's 4 stroking. Anything above that will have it at a nice clean 2 stroke. No clue what that setting is, and I would imagine it's going to vary enough so there is no assurance where mine is set will have a lot of bearing on what it takes to set yours?

Regarding props, the one I have the most time on was turning a very noisy 13.6k on a MA 11x6 when I switched to a MA12x6. I've only tached that prop once but I think it was turning around 10.5k (about 70 degrees/1000' asl).

#2 engine is coming around, but I don't think it's running as strong. Had the carb apart, see no reason for the fuel drip, and that drip continues. #1 engine has no hint of this issue.

Picking up a 13x6, a 13x4, and a 14x4 to play with. Had a 12x4 and it was a waste of time, loosing performance in all aspects.

flyitrite

I ran the engine today with the new Macs pipe. The same 12x8 Evo prop did pick up rpm. It went from about 9500 to 9850 static. It also had a different sound. The high speed needle had to be turned in and is now just about 1and 1/4 or less. Temp looked to be 300 sometime and about 290 sometimes also . The Macs is lighter and DOES NOT LEAK! I am thinking of removing it's baffle to reduce back pressure and because it is too quiet now. Could not hear it at 200 yards with some planes up with me . I had the same experience with a 12x5 APC as you Hicks, I thought it would be the ticket but it was not real good anywhere. I plan to balance the 13x6 tonight and maybe try it tomorrow.

hairy46

My Feedback: (1)

Mine will be in next week, anyone running 100LL in these?

flyinwalenda

My Feedback: (5)

Yes. I run it in all gas engines.

ahicks

My Feedback: (2)

flyitrite - just keep the fact that you need a pretty good amount of back pressure, up to the point where the carb's pressure regulator is restricting it, to keep fuel flow to the spray bar at a constant level (nose up, nose down, etc.). If they come out with a "pumper" style carb for these little guys, that won't be a concern. Till then, I'm afraid it is?

flyitrite

A tiny pumper would be the cat's meow. Today was goooood. The 13x6 is THE hot ticket with this plane. After 2/3 of a gallon I decided to lean to peak and back down a touch then filled the tank (4oz !) and went out to put the plane through the paces. This was the first really hard flying and it performed very well. Full throttle most of the time through big outside loops, rolling circs and attempted snaps.... The engine ran more than 10 - 12 mins and when I landed I noticed a high idle. The tank just had vapors, man that sintered clunk is outstanding with smallest Tygon diameter. Macs pipe is perfect no leaks and hard to get the engine over 295F . Idle could be as low as 1750 ( rough) smooth at 2k , smooth again at 2450 and this is where I left it. I can't recommend too much that a high quality mid size digital servo be used to make sure that the position always returns to the same place ( Spek 5030 for me). It makes the idle so much more stable and easy to trim.

SWORDSN

My Feedback: (13)

Anyone flying the 20cc engine? I'm considering for a P38.

flyitrite

Don't have the 20cc Swordsn. Hey Ahicks, you mentioned earlier about the back pressure when I said I was considering taking out the baffle. That got me wondering about nose-up/nose down testing and so I did that today with interesting results. Since it is at a safe to tune point I have been setting the needles for good performance, and while it was idling I tipped the nose down and it died after a second or two. I have been wondering about the "regulator" for a while now. I would think that it would compensate for small changes but this was too much? I am really thinking that it is not at all effective as a regulator. I am having a lot of fun running this little engine and am very impressed with the power at break in, especially with a lighter muffler. Let me know if your experience has been the same with the idle.

flyitrite

Also looked at temps today since I tuned it , but I was surprised by the increase in head temp after holding the nose up at full throttle. Anybody look at temp during hard flight or long verticals? Have any in flight #'s? I see the 320f high in the manual but wonder if that is the common peak.