Outlaw with webra .36 problems
 

We need some help. My friend and I over the winter built extreme flight outlaws and being as O.S. dosent make the .32 any more we decided to go with Webra .36. We used the mouse can muffler instructions found elsewhere on rc universe. Mine runs pretty good but the high speed needle is only 3/4 of a turn out my friend had to put a new motor on his cuz his first one was junk. We were breaking it in today and about the fourth tank of fuel we thought we should start bringing up the rpm. It would stumble and die above 1/2 throtle so I pulled the pressure line of the muffler and it would advance to full throtle nicley then slow down a few hundred rpm. We put a restriction in the pressure line and did the same thing (1/2 throttle and die) pull the pressure line off and would run good. The pressure nipple is just after the bend in the header any one have any ideas on this.

RE: Outlaw with webra .36 problems
 

Do you have a picture? It would be great to see the header length, nipple position, and size of the can....

RE: Outlaw with webra .36 problems
 

What prop, what fuel and how did you break it in?
As for the pressure tap, note the red type:
http://www.macspro.com/pressure.asp

RE: Outlaw with webra .36 problems
 

You may want to try putting a angle on the end of you pressure tap, facing like a scoop into the exhaust. If it's flat and the exhaust is blowing across it it will create a low pressure. It fixed a similar problem for me once.

RE: Outlaw with webra .36 problems
 

Put the stock muffler on it, add 4 ozs of castor to a gallon of store bought fuel, and run it with a 8x6 prop. The engine should be able to run slightly rich and cool at 17-18,000 this way. Run it like this, or even with open exhaust for a few tanks until the exhaust is free of metal [check the spray with your finger] and until the engine can hold a slightly rich scream. Any half decent .36 should be able to turn a 8x6 about 20,000, but let the engine "work up to it". In between runs, make sure that every bolt on that engine is still snug and monitor every crevise for signs of leakage. If the engine doesn't stay pumped up [indefinitely] after bringing the piston up to TDC, damage has been done that at this point a careful breakin might not help. Once you get a good baseline of what the engine should be doing, then go off and play with the pipe.

RE: Outlaw with webra .36 problems
 

The problem that we are having is too much pressure coming from the pressure nipple and making the motor too rich to get the motor up on the high side. With the exhaust feed line unhooked the motor will run up with no problem but boggs down " only slightly" after it is at full throttle for a couple of seconds. We tried a wire tie at first closing off the exhaust pressure line to the tank. Then we realized that we couldn't close of the vent line or the fuel couldn't get into the motor. Sorry that one was a brain fart on my part. Next we tried putting a peice brass tubing in the pressure line that was crimped down on both sides. Worked a little but not enough. The outlet stinger on the tuned pipe is made out of 1/4" brass and is made for a .32 Webra. Since I am using a .36 Webra I was thinking that maybe I just have too much back pressure in the system and I should try to build another one with a 5/16" of 3/8" outlet stinger to reduce the back pressure? What do you guys think? When breaking in the motor we never ran it over 1/3 throttle and we had a good temp gun watching it. The motor never got over 190 degrees ever. It smoked good and puked out plenty of oil. I have a APC 9X8.5 pylon prop on the motor and am running wildcat 2 stroke/4 stroke fuel with 15% nitro and 18% oil content. I don't have a stock muffler to try on the motor and for a Webra .32 they tell you to run a VESS 9X6-9X7 prop so I don't think that a 9X8.5 would cause problems with a Webra .36 motor. The funny thing is it runs great with the pressure line unhooked but I think it might need a little pressure at full throttle! I will try to post some pictures of the setup latter tonight so that you guys can see what I have and what it looks like.
Anything that you guys can think would help. I really like this plane but am getting tired of working on the motor trying to get it to run right.

Thanks
Newflyer

RE: Outlaw with webra .36 problems
 

Newflyer,

These Webra engines are designed to run on low nitro, 10% being the limit, so that 15% may require a head shim...
This is an ABN engine and as such should be broken in as per Dar Zeelon's recommendations... Do a search here, he has written a very good thread about break in. Break in shall be performed at full throttle on a not that rich main needle setting.
It may sound obvious, but did you check that your fuel line is free from gummed oil deposits that would put to much restriction ?

RE: Outlaw with webra .36 problems
 

Hi!
Symptoms is too much nitro!
Use 5% and you will notice how good this engine is!
No running in time is necessary! It will function and throttle just from the start if you use the correct fuel.
Suitable prop is a 10x5 APC or 9x6-9x7. Expect around 14000-15000rpm on these props and 5% nitro. Nova Rossi or Rossi 3-4 glow plug is best. The Webra 3 plug is a Rossi 3!

RE: Outlaw with webra .36 problems
 

So you guys are saying that running too much nitro is causing the motor to be too rich. Remember that the exhaust is putting too much presure in the tank. I'm not so sure that running less nitro in the fuel will cure that. y friend tat is helping me has the exact same setup as mine. We built them on the same table at the same with the same motors,tuned pipes ,same props even tapped the headers in the same place using the same size exhaust tap. I even ordered the motors at the same time and we put them on the planes at the same time. My friend is using 30% wildcat heli fuel and his runs just fine. We broke them in the same way too! If I am running 15% nitro on mine and he is running 30% nitro on his motor then what you guys are saying is his shouldn't even be running with that much nitro. Like I said if you leave the pressure line off of the tuned pipe the motor runs good. I will try to buy some 5% nitro fuel just to try it but I am pretty sure that isn't going to cure my problem but at this point I am up fo anything.

Thanks Guys!
Newflyer

RE: Outlaw with webra .36 problems
 

Here is a pic of newflyer and my setup this is actually a pic of mine but the two planes are identical

RE: Outlaw with webra .36 problems
 

Sorry I didn't get the pictures posted last night. Here are a few of my outlaw and the home made tuned pipe set up. This is built just like the ones built on the thread on flying Giants . Here is a link to it also.

http://www.flyinggiants.com/forums/f...-outlaw-9.html



Newflyer (not really)

RE: Outlaw with webra .36 problems
 

It looks to me like the stinger is too small in diameter. I could be wrong though...

RE: Outlaw with webra .36 problems
 

Danno,
that is what I am thinking too. I just bought 2 new butane cans and a brass stinger that is 5/16" and another one that is 3/8". The one that we have on the motor now is 1/4". I think it is causing too much back pressure and it is causing the motor to get too much fuel and the needle can't lean it out.




Newflyer

RE: Outlaw with webra .36 problems
 

It also looks a bit long.

RE: Outlaw with webra .36 problems
 

and FYI your coupler shows that there is a big gap between it and the muffler, it should be no more than a 1/16 gap. if you don't correct this the coupler will burn through quickly! and yes your stinger is to small and too long, this causes the over pressure on the fuel system, as well as excessive heat.

RE: Outlaw with webra .36 problems
 

Ditto to everything lfinney said, as well as a few of our favourite Europeans.
I would also add two or three ridiculously simple things that I do before racking my brains, time, energy, and bank account to solve these sort of running problems when I run into them (heh,heh). I am a strong advocate of ruling out the easiest and cheapest things first.
#1)Backflush the needle valve passage ways HARD, it is simple and quick to do, just remove the needle itself entirely, put the carb. to full open, then have a buddy block the outlet tube of your exhaust while you spin the engine with the electric starter for about 1.5 seconds (no igniter). the blocked exhaust will pressurize the fuel tank hard and send a geyser of fuel out of the hole where the needle normally resides. Carefully clean the needle itself and put it back in. Now, right there, most guys that are'nt running fuel filters are amazed that the needling of the engine changes (the smallest little hair of garbage in the needle passagway itself tends to cause bizare-intermittant and nerve wracking to figure out running problems when you don't know this technique). Oh yeah, with the Outlaw, the stock way you have your engine mounted, turn the airplane upside down so you don't slam that geyser of fuel into your helpers eyes...
#1BNow that you have ruled out carburation problems by ensuring accurate fuel delivery, don't even think about even turning the engine over until you put a fuel filter in the line between the tank and the needle intake. For years I have had to listen guys who boast about double and even triple filtering their fuel and then still blame innocent fuel on their running problems :eek: When in fact the cheaply mass produced fuel tanks that we use (for sport) have plenty of flotstam breaking off from the inside all the time (think about that clunk bouncing around in there on that blow molded seam!
#2Now that you have a filter in the feed line, there is a huge advantage because the third plumbing line is unessecary, you just pull it apart behind the filter to fuel it
Never have anything on your airplane that is'nt necessary!
#3Indeed your stinger IS to small but lets talk about what I mean by that for a second. Your exhaust system just the way it is; May actually be tuned magnifiently well suited to a different RPM range that can be achieved on much smaller props that work well on smalller, cleaner, lighter airframes or at least less pitch for your current setup. But certainly not a ......what was it that you said? 9 x 8.5"? The only 45/46 class stock engine that I've ever seen unload that range of prop load to peak H.P. is the Y.S. .45 (rear exhaust version). That prop is certainly not suited to a piped Webra .36...... Bigger (and much heavier) block allowing more room for the bypass ports.
#4Now lets talk about your stinger again, .... Without going through two stroke resonance theory; I will put it like this; constricting the outlet of a TRULY tuned 2-stroke exhaust system effectively supercharges the whole air pumping system HARDER. And after all, what is any internal combustion engine but an attempt at a more efficent air pump so that we may combust more fuel to make more power. But there comes a familiar point that we call "thermal runaway" were suddenly even our best alloys start to let go, and no matter how good the oil mixed in the fuel is ,....,.... , what happens next hurts. What you are seeing is the onset of thermal runaway when you talk about seeing a "slight" sag in RPM.... NEVER let that happen to your engines; not even for three seconds!!!!
Also, for any RPM range you can reasonably hope for with the props that will fly an "Outlaw" cut the stinger length by a whole halve before you widen' its diameter;

"NewFlyer" go to a much smaller propeller load, in your case just getting comfortable with the airframe you might really like a9 x6" your overheatinng "needling" problems will probably go away right there, and the airplane WILL be fast on that prop. then if that is not already too fast for you, go to an 8 x 7" for straightaway and DOWNLINE speed. Then depending on how you work at these sort of solutions, I may choose to offer you an uncommanly fast design

RE: Outlaw with webra .36 problems
 

RE: Outlaw with webra .36 problems
 

I'd be tempted to relocate the pressure tap to somewhere on the can, even on the front face, to buffer out the pressure variations for starters. But yes I know many header tap installations work well - although just about everything I read recommends against it, viz:

[link=http://www.macspro.com/pressure.asp]Pressure taps[/link]

Just tossing this out there. Your buddy's installation looks the same, but ?

MJD

RE: Outlaw with webra .36 problems
 

Newflyer, any more tests ?

RE: Outlaw with webra .36 problems
 

Sorry guys I have been away from this thread too long. I bought 2 butane cans and went to the local hardware store and bought a stick of 5/16" brass and a stick of 3/8" brass tube. I couldn't find any aluminum tube smaller than 3/4" for the inlet pipe so I bought a piece of brass that is 5/8" OD that will work. A friend is putting the two pipes together for me today here at my shop. I will be able to report back soon on the two new pipes. Hopefully one of them will do the trick. I will try all three with my tach and let you guys know if there is a big difference in RPM.

Now, C_Roundy Thank you so much for going into so much detail on my motor and pipe! To answer some of your questions.

#1)Backflush the needle valve passage ways HARD.

Did that before I even posted on this thread.

#1BNow that you have ruled out carburation problems by ensuring accurate fuel delivery, don't even think about even turning the engine over until you put a fuel filter in the line

Haven't done that one yet but I will.

But certainly not a ......what was it that you said? 9 x 8.5"? The only 45/46 class stock engine that I've ever seen unload that range of prop load to peak H.P. is the Y.S. .45 (rear exhaust version).

Here is link to webra's website and the specs: on the .36.

http://www.webra-austria.at/motor.ph...r=AERO&lang=EN

Webra recomends a 11X7-12X6 prop for this motor and a RPM range of 2500-17,000 Even though I am raising the prop pitch by 1.5 degrees over the 11X7 I am also decreasing the size of the prop by 2 inches. I am not against switching to a smaller prop but this one should get me in the ball part to fly without all the problems.

Don't get me wrong C_Roundy but you state that "If this isn't too fast for you then go to an 8X7 prop. I am not too afraid of the speed of this plane by any means! My first electric plane 6 years ago was a Hobby Lobby Projeti with a Mega 16-15-3 motor runing a 4S1P thunderpower battery. Not super fast but I would say roughly 120-135 MPH. This plane should be in that range I would say. Not really looking for the top speed on this one I will leave that up to my Diamond Dust with the O.S. .40 VF or my Whiplash with the Jet Fire .50 on it!
http://www.youtube.com/watch?v=m55PR...eature=related
I will try to cut the stinger in half on the first tuned pipe after I have tried the two other pipes.
They are recommending a 8X7 or a 9X6 to a 9X7 prop on a Webra .32 motor.
Sorry got to go for now.
I will let you guys know of all results soon.
Thanks

Newflyer

RE: Outlaw with webra .36 problems
 

I use the mousse cans from Flying Z Hobbies and they are great. Messing around with butane cans is a real pain and the mousse cans are available either separately or with the header and can already together. We run the cans unsupported. They just hang on the header pipe. With my deltas I run an APC 8X8 for speed or a APC 9X7 for better pull on a Webra 32. I use the same props with the OS 32 also. I do not have a 36 but I would expect to use the same prop. Tina Z from Flying Z runs the mousse cans with the OS heli 37 and a Graupner 9.5X5. These engines really turn up with the 9.5X5 but her planes run about the same speed as mine.

Wiggy

RE: Outlaw with webra .36 problems
 

OK,
Just got finished trying all three mouse cans mufflers. First was the one we built with the 1/4" outlet pipe. ( thats the one that is painted black). Started the motor let it warm up for anout 30 seconds at idle the run the motor up and at half throttle the motor supttered and wouldn't get up on step. I shut the motor off and checked the high speed needle and it is 1 turn out from closed. I reset it to the same 1 turn out and tried it again to make sure. Same result. Tried the next can with the 5/16" outlet pipe. (The middle can). Started the motor let it idle for 30 seconds then stabbed the throttle and the motor jumped up to full throttle in about 2 seconds!! I shut the motor off and let it cool down for a little while then put the third can on the motor with the 3/8" stinger ( the one on the right)and fired it up. The motor started good and once it ran for a couple of seconds I stabbed the throttle and it went to full throttle in 2 seconds as well. The whole time I was doing this I had a friend holding the plane while it was setting on a stand. My friend told me that the motor felt like it had slightly more pull on the last pipe with the 3/8" stinger. We took the plane outside so we could tach the two new cans. We started with the one that had the 5/16" stinger on it. the tach reading was 13,700. We tried the second one with the 3/8" stinger and my friend was right we hit 14,200 on it!! That was all without touching the high speed needle. Now I may be too lean on the high speed but I need to do a little more testing with a good temp gun and moving the high speed needle while the motor is running. The needle is really close to the prop so I am a little weary of getting my fingers too close to the prop spinning at 13,000-14,000 rpm! Here is a couple of pictures of the three pipes setting next to each other. I will try to sand and paint the two new ones this weekend if possible. Got a lot of Spring honey do's to get done so that I can get to the field and fly soon.
1-Fuel not the problem!
2-Prop not the problem!!!!!!!!!!!!!!!!!!
3-Tank not the problem!
4-Fuel filler line not the problem!
5-Placement on the pressure nipple not the problem!
6-Carb not the problem!
7-Needle on carb not the problem!
8-Glow plug not the problem!


Too small of outlet stinger THE PROBLEM!

Now remember I replaced the motor once not because it wouldn't get on the high side but because it would not start and when it was turned over by hand with a prop on it you could feel a REALLY tight pop at the top of the compression stroke. The motor was like that the moment we took it out of the box! I haven't taken the head off of the motor to see what it is nor do I think I will. I will ship it back and ask for a refund or will ask the seller to give me credit for it and but something else from him that cost more. I know he is a small business and it really sucks to make a sale then have someone send something back and ask for their money back. I own a small business and know what that is like! I will get the can on the motor and get the plane back together and run the motor with a temp gun and let you guys know if I am too lean or if there is more RPM to squeese out of the motor. I will try several more props on this plane and let you know what they do as well. I am a little iffy about running a wooden prop at 14,000 RPM balance or not. If you guys have used any wooden props that you can let me know about and what the RPM was I would feel a lot safer about trying one on this motor.

If you are going to make a tuned mousse can for a webra .36 be sure to use a 3/8" stinger on the end so that you don't have to go though this mess..

Newflyer (not really anymore)

RE: Outlaw with webra .36 problems
 

Well I got the throttle servo replaced in the outlaw Sunday and got the larger can on the plane and everything put back together. got it on the plane stand and started the motor today. and the pipe works great. Didn't fly it yet but the motor starts good idles good without dying. A little fast on the idle but the motor needs some flights on it still to get it broke in some more. The temp was around 185-195 after warm up and the RPM was still at 14,200 on the tach. I should be able to fly the outlaw in a week or two. I have to be out of town this weekend so thats out. The weekend after I should be able to put it in the air.



Newflyer

RE: Outlaw with webra .36 problems
 

Good news you got it figgered out.

What is the concern about exceeding 14k with a wood prop? Wooden props are routinely run to much higher figures than that, depending on the design and diameter. A good wood prop is a tough critter.

MJD

RE: Outlaw with webra .36 problems
 

Just to let you know what that engine is capable of or what you are shooting for with a mousse can:

The best top speed AND best acceleration with this engine and plane combo have been with an APC 9X7 prop @ 17,500 RPM on 10% fuel using a Macs tuned pipe with the stinger’s I.D. reduced to 5/16”. The pressure tap is on the pipe’s apex. He used a 1120 and a #1140 but I would suggest the Macs # 1130 tuned pipe and reduced stinger. OS plugs (8 thru 5) have not been so good on these engines in respect of plug life or smooth operating range. Look at Enya # 4 , # 5, or my favorites the K&B 1-L, K&B HP.


http://www.rcuniverse.com/forum/fb.asp?m=7589177
http://www.rcuniverse.com/forum/fb.asp?m=7644321
http://www.rcuniverse.com/forum/fb.asp?m=7871483

newflyer, the link you had above is for the Webra 55 not the 36, even so don't think the props the MFRs list are written in stone.

A 9X8.5 is too much load to get the engine into where it makes most of it's power.

Example: 9X8.5 @ 14200 = .98 HP VS 9X7 @ 17500 = 1.52 hp(edited) with higher thrust, unload and pitch speed.

These engines should be broke in with a light load prop at wide open throttle rich two stroke with a known working exhaust/muffler first.

0 to 10% nitro for best results.



I hope this helps.