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UMS Radial Engines. Who's got one and are they any good?

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UMS Radial Engines. Who's got one and are they any good?

Old 08-21-2019, 07:25 PM
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Parkfley1
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Default UMS Radial Engines. Who's got one and are they any good?

UMS Radial engines have hit the market. So who's got one and are they any good? In the videos they look and sound great, but nobody that I know in Aus has ordered one yet. Keen to hear from anyone who's seen one in the flesh.
Old 08-29-2019, 12:22 AM
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Parkfley1
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That good hey? I guess I'll hang onto my money and see how they fair in the long term...
Old 01-03-2020, 09:10 PM
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Ive been thinking the same thing as ive never seen one and are wanting to know more about them.
they have open rockers so the inside of cowl might get a slight bit of oil but they include the exhaust unlike the saito radials (have to sorce a MRS, keleo etc) and run with less oil vs the saito.

lots of options as you can see in the link below, but the 5-75cc is the one that catches my eye the most for the $$$
UMS Radial Engines : UMS Radial Engines : UMS Radial EnginesFOURTH_SECTION : Austars-Model.com
Old 01-05-2020, 12:56 PM
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TimD.
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Well I have a 7-90 and so far, runs Very GOOD! Now I only have {4} 32oz tanks run through it so far and am waiting on the new TopRC Corsair to put it in. I have a 3-blade 22x12 Biela wide blade prop on it and am getting tach readings from 1000-1050rpm at idle to full at 54-5500rpm. Not bad when compared to my Saito 3-90 about the exact same Rpm's with the USM getting 100 more rpm at full throttle.

If it holds the same as my EVO's 7-77 it will be a winner. I have logged ( a guess) 15-20hrs of run time one them. And they are ready for more. Three flying seasons pretty steady.
I might get the 5-125 next. It will fill the gap between my 90's and Moki 180. Price is much more attractive as well.

Last edited by TimD.; 01-05-2020 at 12:59 PM.
Old 01-16-2020, 07:34 PM
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how would you compare the motor to the FG-90? i like saito due to beong made in Japan and comes with a 3yr warrently, i like the idea of UMS but i cant find any real videos of planes flying or much info on them so far.
Old 01-18-2020, 07:19 AM
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TimD.
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Well they are both made quite well. Good machine work on both. The only real difference between the two are the 3 cylinder and 7clinder. The Saito's 3 cylinder has a more Throaty poping sound from the larger cylinder volume, where the UMS has a constant rumbling from the 7 cylinders. The UMS is quieter than the Saito, I believe it is from the smaller cylinder volume, but sounds more scale to me.
It sips fuel a 24oz tank would be more than enough for a 15-20 min flight.
Old 01-28-2020, 02:42 AM
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Well got to see the 5 cylinder 125cc UMS engine up close and running this week. Machining looks good and finish is excellent. From the look of it, every bit as good as a Moki engine. Comes with a factory exhaust ring as standard which is cool and I love the external rockers for ease of maintenance. It's definitely on my list.
Old 01-30-2020, 06:06 PM
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Default UMS radial

There are lots of post on GLOW ENGINES thread about converting there glow radials to gas. I have a 7-77 glow and its not close to moki quality. I have been trying to get it to run correctly for
way too long without success. I swapped carburetor on advice from GLOW ENGINES thread and that helped a bit ...cost $99.00 .....then theres the fuel issue, must blend from normal fuel and methanol
50/50 ...also need to invent your own starter battery to power 7 plugs. If there gas is like there glow, proceed with caution !! My engine runs strong but won't idle without glow power on...
Have to worry about two bottom cylinders getting hydrolic lock....wish I had my money back
Old 04-23-2020, 03:17 PM
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Converting those older glow radials is more trouble than its worth to be honest, better to just sell it and buy a gas Saito or UMS radial or continue to run it on glow fuel.

From what I'm seeing the UMS are proving really good and very easy to setup and run, still waiting to see some flight videos.
Old 06-30-2020, 05:39 PM
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You won't find many videos because flying a costly and unreliable engine is a bad combo in a plane that's costly too....
I had 7-77 glow......selling it was best thing . yes there pretty but QUALITY and reliable. ..no
4 strokes hard enough to keep glow plug hot but 7 cylinders ...firing every other cylinder...piston going up and down...= cold glow plug.
Then u have to worry about oil in bottom cylinders causing lock up.
Also big pain to adjust valves....lube up after using or rust...crappy pushrod / rocker design, heck pushrod so loose its a joke...
I read forum on this engine on this web site and nothing but good to say UNTIL someone put different carbon on....
Then all of a sudden the "expert" clamed the carb that came with engine did not supply enough fuel and bla bla bla buy new carb and adapter $$$$$$
This is same guy at first braging about engine?????
could it be that a company rep. Poses as hobbies and post crap just to sell his companies junk???
Old 06-30-2020, 06:48 PM
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I'm just a confused are we talking about the Evolution 7-77? or the new UMS range?
I don't do glow, to much of a headache in 2020, in my opinion its better to sell the 7-77 and buy a FG-90 at the very least. The FG-90 will give you hours and hours of trouble free enjoyment.

Last edited by su27flanker; 06-30-2020 at 09:24 PM.
Old 07-02-2020, 06:52 AM
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marksp
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Default UMS 5-125 video (test stand)

Originally Posted by Parkfley1 View Post
Well got to see the 5 cylinder 125cc UMS engine up close and running this week. Machining looks good and finish is excellent. From the look of it, every bit as good as a Moki engine. Comes with a factory exhaust ring as standard which is cool and I love the external rockers for ease of maintenance. It's definitely on my list.
Quick vid of my buddies UMS 5-125 on test stand -

Between us we have a bunch of radial engines - He has 4 or 5 Moki's (S250's and 1 S300) and a little Saito FG-60R3 and I have the Tomahawk branded UMS manufactured 5-250, a Moki S250, and a FG-60R3 and can say the UMS line up is quite impressive! In addition to a well designed exhaust ring (sounds great), both the 5-125 and the 5-250 include genuine Walbro carb. His 5-125 also included an electric pump. Both include RcExl ignition with tach out (key on radial's to keep from over revving). They start easily, transition well and pull max ground RPM with recommended prop.

Fairly certain if you perform recommended maintenance, run recommended oil/fuel ratio and keep RPM in range, they should provide many great sounding flights!

Last edited by marksp; 07-02-2020 at 07:06 AM.
Old 07-02-2020, 07:05 AM
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Default Tomahawk 5-250

Here's my 5-250 on test stand

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Looks great! Runs great! Sounds great!

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