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Old 05-07-2015, 02:24 PM
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Not so great that your muffler broke as well was hoping mine was just bad luck, looks like the stock mufflers may need some rethinking. As you prob know the engine does share the same exhaust flange size as DLE 55 and EME 55/60 so side dumps or pitts are readily available, be suprised if Leo does not read this and send you a new muffler though.

Actually spent a few hours today finnishing my DJ 72 install and it is ready for a flight, unfortunately work, weather and home life will prevent this for the next two weeks at least. But its getting there.
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Old 05-07-2015, 04:52 PM
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Now I am thinking a 16oz. Bud Bottle muffler.I just never did one on a 50-70cc engine before.
Not sure of the exit tube size opening.
I ordered some brazing rods from DA today already have the header flange and bends that I will need and will start working on the cans tonight.
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Old 05-10-2015, 11:25 PM
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If the stock muffler broken, I will send you a new .
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Old 05-10-2015, 11:57 PM
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My plan, 89inch Extra 260SS

Very powerful! Low vibraion! But... I can not fly 3D (>﹏<)
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Last edited by djpower; 05-11-2015 at 05:14 AM.
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Old 05-11-2015, 06:11 AM
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Quote:
Originally Posted by djpower View Post
If the stock muffler broken, I will send you a new .





Leo, that would be good to have a new muffler.I will PM you my address.
Thank You
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Old 05-12-2015, 02:29 PM
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Managed to run mine today out the back just to check installation and throttle end points before cowl will be fitted and flown. Started ok but then had no full throttle, had messed with the needles a bit before realising I had blocked the pulse port when repositioning the carb.

Needles now at 1.5 turns each she started and runs good, but was quite jumpy/viby at idle and very smooth above that. Unfortunately due to me messing with the needles I cant be sure if the rough idle is due to being a bit rich at the bottom end. Hope I can tune it a bit smoother or my cowl wont last long as its a Sukhoi with a large cowl with little support.
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Old 05-12-2015, 02:34 PM
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keep leaning the low end until you do not get transition, then richen until it does and you should be right on the low end.
Just remember when you lean the low end you are leaning the high end also.








Milton
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Old 05-12-2015, 06:00 PM
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You should be able to tune the idle vibe out.The one I have is good at idle.
The way I set the low is to just go one click above idle and lean it out for the highest rpm.Then richen it until the rpm just starts to drop,then about 1/8 richer.I have done it both ways like Milton describes,but I just like to hear the rpm drop.
I gave my muffler to a friend to weld up,until I get one to replace it.
So far I like the engine, the last time I mess with the needles I was getting 6885 with GREAT throttle response.You can tune out every bit of the burble or go as rich as you want.
Rite now the plug is running a light tan and that is where I will leave it.
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Old 05-13-2015, 12:27 AM
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Leo, that would be good to have a new muffler.I will PM you my address.
Thank You
OK!^_^
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Old 05-13-2015, 01:29 AM
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I should have added that I did not bother trying to set the low needle yesterday due to knowing as soon as I fit that huge sukhoi open front cowl it will need retuned anyway. This has happened on two other engines that have been in this airframe. It will get its final tune when cowl is on.

Yes the way you guys set the low by the transition is exactly how I set my engines.
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Old 05-18-2015, 07:41 PM
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Tried to get some time on the 72 today after getting the muffler mounting flange welded back on.But the muffler exit tube broke off this time after one five minute flight.
Got the brazing rod from DA and have the header made up now.Going to try a Bub Bottle muffler just to see how that performs.Not a real fan of canisters or pipes,but push may come to shove on this one.One other thing I thought of doing is to send the stock muffler to Jtech and have one built just like it.
I do have another muffler on the way that Leo has sent me.
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Old 05-20-2015, 03:24 PM
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Ran the 72 tonight with the "Bud Bottle"muffler.With a 12" header and a 3/4" exit tube 3" long it lost rpm at 6750,i was getting 6880-90 with the stock muffler. Don't know much about the Bud Bottle muffler it's all new to me with gas. I used them on glow engines before and always got a little more rpm,but everything held together.I made two of these mufflers up, just ran the second one with a 3/8" exit tube 3" long with a 45degree bend in it.I richen the low up a bit and jump to 6850,and it had a more of a canister sound.You could hear the prop making more noise than the engine.
Has anyone ran a canister and got more rpm than a stock side dump?
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Last edited by closetguy; 05-20-2015 at 04:45 PM.
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Old 05-26-2015, 11:41 AM
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Well I received not one but two replacement mufflers today from Leo.Nice to be able to get replacement parts for this engine.
The Bud Bottle muffler didn't last long before the exit tube fell off.
I have a Chip Hyde canister that I mount on it and lost 200 rpm,but at lease I could fly it.
Now that I have the new stock side dumps, I am going to have both welded at the mounting flange and exit tube.To see if that will take care of them breaking at that point.
Still happy with the way the engine runs.Starts easy,smooth and fast transition.Very EME like engine.
As of now,(time will tell) I spent a lot more on engines in the past that didn't run this well.
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Old 05-26-2015, 01:24 PM
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Received my dj72 today , packaged nice ; alot better then some of the Chinese / Taiwan engines in the past . I don't care much for the styrofoam type packaging as it crumbles easy but at least they put it in a plastic bag. First impressions looks as good as an eme . I will tear it down when I get some free time .
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Old 05-26-2015, 05:06 PM
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That's good to hear, someone else with some experience will give there impressions on this engine.
When I installed the FB ring I thought the cylinder honing was really well done.
I know its to early to ask, but I will anyways, do you think you might be selling these in the future.
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