New .90 gas engine (15cc)
09-13-2010, 01:31 AM
#226
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RE: New .90 gas engine (15cc)
I've got my JBA 15 mounted on a beefed up Kadet Senior. This one has a rocket launcher built into the wing. I fly at a private ranch so no worry about AMA rule violation.
09-13-2010, 11:16 AM
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RE: New .90 gas engine (15cc)
ORIGINAL: erieqc
airborne2.4 I'm using a menz 16x6 thats what Tom at Valley View suggested. I also have a Vess 16x6 I want to try.
airborne2.4 I'm using a menz 16x6 thats what Tom at Valley View suggested. I also have a Vess 16x6 I want to try.
09-13-2010, 11:30 AM
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RE: New .90 gas engine (15cc)
ORIGINAL: Wayne H
I've got my JBA 15 mounted on a beefed up Kadet Senior. This one has a rocket launcher built into the wing. I fly at a private ranch so no worry about AMA rule violation.
I've got my JBA 15 mounted on a beefed up Kadet Senior. This one has a rocket launcher built into the wing. I fly at a private ranch so no worry about AMA rule violation.
09-13-2010, 12:11 PM
#231
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RE: New .90 gas engine (15cc)
ORIGINAL: ghitt
Good morning David.
I was going to give you a call but decided to post, hoping that someone else may benefit.
<![if gte mso 9]><xml><w:WordDocument><w:View>Normal</w:View><w:Zoom>0</w:Zoom><w
oNotOptimizeForBrowser /></w:WordDocument></xml><![endif]><p class=''MsoNormal''>I bought this engine as soon as Valley View posted it on their site. I took it to the field and created a lot of interest but of course they were skeptical of such a “little” gasser.<span style=''''> </span>Just wait until they see my Magnum .52! They wanted me to test it first, imagine that.</p><p class=''MsoNormal''> Here is my experience:</p>
Good morning David.
I was going to give you a call but decided to post, hoping that someone else may benefit.
<![if gte mso 9]><xml><w:WordDocument><w:View>Normal</w:View><w:Zoom>0</w:Zoom><w
oNotOptimizeForBrowser /></w:WordDocument></xml><![endif]><p class=''MsoNormal''>I bought this engine as soon as Valley View posted it on their site. I took it to the field and created a lot of interest but of course they were skeptical of such a “little” gasser.<span style=''''> </span>Just wait until they see my Magnum .52! They wanted me to test it first, imagine that.</p><p class=''MsoNormal''> Here is my experience:</p>
ORIGINAL: gasrchobbyengines
Has anyone been able to get one of the engines to run in the mid range without the anoiying burble. After the first dle 30 experience I had I am still weary of an engine that does not sound right running in the air at half throttle.
I already have a plane set aside for one of these engines and I want to buy one from Jim at Agape racing as soon as I can see these little engines are going to be relaiable.
All the videos I have watched so far, the engine is either being held full throttle or idling. the ones that the engine is running mid range sound like they have a bad burble.
I hope this little motor turns out to be another good gasser.
ORIGINAL: regets ama
JUST SOME FOLLOW UP ON MY JBA 15,
AFTER 5 HOURS OF RUNNING ON SYNTHETIC INCLUDING 2 HOURS OF FAST IDLE BREAK IN I STILL HAD ALOT OF BLOW BY PAST THE RING AND MINIMAL COMPRESSION. IT HAD A FAIR IDLE AND GOOD TOP END BUT THE MIDRANGE WAS UNDESIREABLE.
I DISASSEMBLED AND FOUND THE CYLINDER SLEEVE TO BE GLAZED (NO RING SEATING) = NO COMPRESSION
JUST SOME FOLLOW UP ON MY JBA 15,
AFTER 5 HOURS OF RUNNING ON SYNTHETIC INCLUDING 2 HOURS OF FAST IDLE BREAK IN I STILL HAD ALOT OF BLOW BY PAST THE RING AND MINIMAL COMPRESSION. IT HAD A FAIR IDLE AND GOOD TOP END BUT THE MIDRANGE WAS UNDESIREABLE.
I DISASSEMBLED AND FOUND THE CYLINDER SLEEVE TO BE GLAZED (NO RING SEATING) = NO COMPRESSION
I already have a plane set aside for one of these engines and I want to buy one from Jim at Agape racing as soon as I can see these little engines are going to be relaiable.
All the videos I have watched so far, the engine is either being held full throttle or idling. the ones that the engine is running mid range sound like they have a bad burble.
I hope this little motor turns out to be another good gasser.
09-13-2010, 09:02 PM
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RE: New .90 gas engine (15cc)
Original:Airborne 2.4
I am having to start over with this engine. I have run a gallon of fuel through this engine so far using the Amsoil Saber 100:1 mixed at 20:1. Well, I have not been able to get the engine to open up. I don't have a tach, but I can tell it is not reaching high RPM's. Sounds really rich and almost like it's four stroking. I have since read that the Amsoil Saber 100:1 does not mix like the other oils, meaning you do not need as much. So, I have mixed a new batch using only half the oil making it 32:1. I am getting better RPM's, but still no where near broke in yet. I get enough power to fly the plane of course because it is a high lift wing. I am using a 13X8 Master Airscrew. I have High and Low needles set at about 1 3/4 turns out. I am thinking of holding off on the Amsoil and using the petroleum based to break in as others have been suggesting.
What was your break-in process? Did you use pennzoil 2 stroke air cooled petroleum based oil 25-30:1, Stihl HP Ultra 32:1, Amsoil, prop size/s etc? What's kinda rpm's are you getting?
I am having to start over with this engine. I have run a gallon of fuel through this engine so far using the Amsoil Saber 100:1 mixed at 20:1. Well, I have not been able to get the engine to open up. I don't have a tach, but I can tell it is not reaching high RPM's. Sounds really rich and almost like it's four stroking. I have since read that the Amsoil Saber 100:1 does not mix like the other oils, meaning you do not need as much. So, I have mixed a new batch using only half the oil making it 32:1. I am getting better RPM's, but still no where near broke in yet. I get enough power to fly the plane of course because it is a high lift wing. I am using a 13X8 Master Airscrew. I have High and Low needles set at about 1 3/4 turns out. I am thinking of holding off on the Amsoil and using the petroleum based to break in as others have been suggesting.
09-13-2010, 09:50 PM
#233
RE: New .90 gas engine (15cc)
When you mix Amsoil Saber at ratios less than about 80:1 it forms hard carbon on everything. Messes up the whole insides of the engine eventually.
If you want to run 20:1 go with a mineral oil like Pennzoil Air Cooled. What carbon is formed is soft like smut.
If you want to run 20:1 go with a mineral oil like Pennzoil Air Cooled. What carbon is formed is soft like smut.
09-13-2010, 11:01 PM
#235
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RE: New .90 gas engine (15cc)
I've got about 90 minutes of run time on my engine. I'm using Poulan synthetic oil @ 20:1. My plan is to finish up the 1/2 gallon I started with, then go to a 32:1 mixture.
I have had very good luck with a 13x8 prop and have achieved a smooth top end at 10,400 rpm. Have not run very long at that rate but it seems to peak out very nicely so far.
Have gotten steady idle rpm of about 2200. Transition has been pretty good if I don't move the throttle too quickly. The engine is in my plane and I haven't done much mid range testing yet. I think I will move to a 14x7 prop, make a few more adjustments, and prepare to do some flying...
Still have quite a bit of blow-by, and I too am going to seal up the muffler... and re-do the muffler gasket.
Hope the snow doesn't come too soon...[X(] Our field is at 7200 ft.
I have had very good luck with a 13x8 prop and have achieved a smooth top end at 10,400 rpm. Have not run very long at that rate but it seems to peak out very nicely so far.
Have gotten steady idle rpm of about 2200. Transition has been pretty good if I don't move the throttle too quickly. The engine is in my plane and I haven't done much mid range testing yet. I think I will move to a 14x7 prop, make a few more adjustments, and prepare to do some flying...
Still have quite a bit of blow-by, and I too am going to seal up the muffler... and re-do the muffler gasket.
Hope the snow doesn't come too soon...[X(] Our field is at 7200 ft.
09-14-2010, 03:52 PM
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RE: New .90 gas engine (15cc)
Hey mpascual, it sounds good....
http://www.youtube.com/watch?v=reGjt...eature=related
http://www.youtube.com/watch?v=f5WbM...eature=related
http://www.youtube.com/watch?v=reGjt...eature=related
http://www.youtube.com/watch?v=f5WbM...eature=related
09-14-2010, 04:39 PM
#238
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RE: New .90 gas engine (15cc)
ORIGINAL: airborne2.4
Hey mpascual, it sounds good....
http://www.youtube.com/watch?v=reGjt...eature=related
THIS VIDEO WAS TAKEN TO SHOW THE CUSTOMER HOW START THEIR ENGINE, BECAUSE I RECEIVED IT TO SET THE NEEDLES. YOU CAN SEE , ENGINE DIES AT FULL THROTTLE, BECAUSE THE NEOPRENE TUBE FOR CARB PULSES WAS DAMAGED AND BROKEN ON THE CARB ADAPTER NIPPLE.
http://www.youtube.com/watch?v=f5WbM...eature=related
THIS SECOND VIDEO WAS TAKEN ON APRIL OF THIS YEAR AND WAS WITH A PRE-PRODUCTION UNIT. (DIFFERENT CARB, AND PLUG CAP AT 120 DEGREES). PRODUCTION ENGINES NOW HAVE A DIFFERENT WALBRO MODEL.
Hey mpascual, it sounds good....
http://www.youtube.com/watch?v=reGjt...eature=related
THIS VIDEO WAS TAKEN TO SHOW THE CUSTOMER HOW START THEIR ENGINE, BECAUSE I RECEIVED IT TO SET THE NEEDLES. YOU CAN SEE , ENGINE DIES AT FULL THROTTLE, BECAUSE THE NEOPRENE TUBE FOR CARB PULSES WAS DAMAGED AND BROKEN ON THE CARB ADAPTER NIPPLE.
http://www.youtube.com/watch?v=f5WbM...eature=related
THIS SECOND VIDEO WAS TAKEN ON APRIL OF THIS YEAR AND WAS WITH A PRE-PRODUCTION UNIT. (DIFFERENT CARB, AND PLUG CAP AT 120 DEGREES). PRODUCTION ENGINES NOW HAVE A DIFFERENT WALBRO MODEL.
Regards
09-19-2010, 02:06 PM
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RE: New .90 gas engine (15cc)
Has anyone thought about using this after break-in?
http://www3.towerhobbies.com/cgi-bin...?&I=LXS626&P=7
http://www3.towerhobbies.com/cgi-bin...?&I=LXS626&P=7
09-20-2010, 06:05 PM
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RE: New .90 gas engine (15cc)
They need to comes out with a smaller pipe. That will stick out so far out of the cowl. My buddy bought over the new DLE 20cc rail mount and it has a pipe 1/2 the size probably fit with not too much work and weighs the same. I might run the P51 with no cowl til I have a better option. Any pics on the P51 with the cowl installed?
09-21-2010, 01:21 PM
#243
RE: New .90 gas engine (15cc)
THis is what I have mine installed in. Looking to get in the maiden this weekend at the Warbirds over the Rockies. I put in a 6oz tank, will have a 16-6 Xoar installed. It is looking like my all up weight will be around 9 lbs. Not too bad. 65" wingspan Pica Dora 9.
09-21-2010, 01:24 PM
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RE: New .90 gas engine (15cc)
Has anyone gotten one of these engines to run without the severe 4 stroking in the midrange? Every video I watch it seems they all do it.
09-21-2010, 06:09 PM
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RE: New .90 gas engine (15cc)
ORIGINAL: gasrchobbyengines
Has anyone gotten one of these engines to run without the severe 4 stroking in the midrange? Every video I watch it seems they all do it.
Has anyone gotten one of these engines to run without the severe 4 stroking in the midrange? Every video I watch it seems they all do it.
I hope there isn't some ulterior motive behind repeating it?
The answer is YES. Many have achieved tuning out the mid range "burble"
The secret to tuning these is to use very small adjustments on the needles. each needle will affect the other needles setting.
If you are having difficulties getting rid of the burble - here is my suggestion
Go back to the original settings (around 1 1/2 turns out on each needle).
Make sure you have a prop that applies load to the engine - these are significantly more powerful than "the other (crappy) brand" of 15cc enigne you are familiar with - add about an inch of prop to whatever you use on that brand (if you find one that works successfully on that other brand). Burble is actually caused by a lack of load on the engine (plus rich tuning).
Tune the engine as outlayed earlier in this thread - with VERY small adjustments each time. No more than 22.5 degrees each time, less is even better.
09-21-2010, 06:13 PM
#246
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RE: New .90 gas engine (15cc)
ORIGINAL: gasrchobbyengines
Thank you SOOOO much for the info.
ORIGINAL: ghitt
Good morning David.
I was going to give you a call but decided to post, hoping that someone else may benefit.
<![if gte mso 9]><xml><w:WordDocument><w:View>Normal</w:View><w:Zoom>0</w:Zoom><woNotOptimizeForBrowser /></w:WordDocument></xml><![endif]><p class=''MsoNormal''>I bought this engine as soon as Valley View posted it on their site. I took it to the field and created a lot of interest but of course they were skeptical of such a “little” gasser.<span style=''''> </span>Just wait until they see my Magnum .52! They wanted me to test it first, imagine that.</p><p class=''MsoNormal''> Here is my experience:</p>
Good morning David.
I was going to give you a call but decided to post, hoping that someone else may benefit.
<![if gte mso 9]><xml><w:WordDocument><w:View>Normal</w:View><w:Zoom>0</w:Zoom><w
oNotOptimizeForBrowser /></w:WordDocument></xml><![endif]><p class=''MsoNormal''>I bought this engine as soon as Valley View posted it on their site. I took it to the field and created a lot of interest but of course they were skeptical of such a “little” gasser.<span style=''''> </span>Just wait until they see my Magnum .52! They wanted me to test it first, imagine that.</p><p class=''MsoNormal''> Here is my experience:</p>
ORIGINAL: gasrchobbyengines
Has anyone been able to get one of the engines to run in the mid range without the anoiying burble. After the first dle 30 experience I had I am still weary of an engine that does not sound right running in the air at half throttle.
I already have a plane set aside for one of these engines and I want to buy one from Jim at Agape racing as soon as I can see these little engines are going to be relaiable.
All the videos I have watched so far, the engine is either being held full throttle or idling. the ones that the engine is running mid range sound like they have a bad burble.
I hope this little motor turns out to be another good gasser.
ORIGINAL: regets ama
JUST SOME FOLLOW UP ON MY JBA 15,
AFTER 5 HOURS OF RUNNING ON SYNTHETIC INCLUDING 2 HOURS OF FAST IDLE BREAK IN I STILL HAD ALOT OF BLOW BY PAST THE RING AND MINIMAL COMPRESSION. IT HAD A FAIR IDLE AND GOOD TOP END BUT THE MIDRANGE WAS UNDESIREABLE.
I DISASSEMBLED AND FOUND THE CYLINDER SLEEVE TO BE GLAZED (NO RING SEATING) = NO COMPRESSION
JUST SOME FOLLOW UP ON MY JBA 15,
AFTER 5 HOURS OF RUNNING ON SYNTHETIC INCLUDING 2 HOURS OF FAST IDLE BREAK IN I STILL HAD ALOT OF BLOW BY PAST THE RING AND MINIMAL COMPRESSION. IT HAD A FAIR IDLE AND GOOD TOP END BUT THE MIDRANGE WAS UNDESIREABLE.
I DISASSEMBLED AND FOUND THE CYLINDER SLEEVE TO BE GLAZED (NO RING SEATING) = NO COMPRESSION
I already have a plane set aside for one of these engines and I want to buy one from Jim at Agape racing as soon as I can see these little engines are going to be relaiable.
All the videos I have watched so far, the engine is either being held full throttle or idling. the ones that the engine is running mid range sound like they have a bad burble.
I hope this little motor turns out to be another good gasser.
09-22-2010, 03:13 AM
#248
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RE: New .90 gas engine (15cc)
I agree with aussiesteve...
And I've seen and also tuned MANY J15G engines without 'severe 4 stroking in the midrange' . Usually is caused by bad needles settings, and ALL gas engines can make a severe 4 stroking if you open too much the needles. In many cases, factory settings cause this midrange missfiring.
Regards
And I've seen and also tuned MANY J15G engines without 'severe 4 stroking in the midrange' . Usually is caused by bad needles settings, and ALL gas engines can make a severe 4 stroking if you open too much the needles. In many cases, factory settings cause this midrange missfiring.
Regards
09-22-2010, 01:50 PM
#249
RE: New .90 gas engine (15cc)
+1, proper tuning is the key. There is almost no gasser that will run completely clean if held in the lower midrange just above idle unless loaded well above what our application typically requires. Some seem to feel a gasser should have a throttle like and electric motor, never going to happen, they are to lightly loaded in the midrange for that to be possible.
09-24-2010, 09:29 AM
#250
RE: New .90 gas engine (15cc)
Maybe soon a varible pitch prop will be a option for smaller gas engines. The right amout of load at the right RPM would help that burble sound. Some electric motors have them now. Seems like a swash plate type could be made ......simular to the ones on a Heli.
Another help would be a exhaust system that is like a quiet pipe. At least the burble would not be as loud & with a little tunning of this & that, a better midrange sound would result.
Then there is the throttle plate mod where the 1/2 "moon" on the edge of throttle plate is enlarged a tad. That works good ...sometimes. Make sure you have extra throttle plates if cut too much! Capt,n
Another help would be a exhaust system that is like a quiet pipe. At least the burble would not be as loud & with a little tunning of this & that, a better midrange sound would result.
Then there is the throttle plate mod where the 1/2 "moon" on the edge of throttle plate is enlarged a tad. That works good ...sometimes. Make sure you have extra throttle plates if cut too much! Capt,n
