Parkfley1

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.

Parkfley1

That good hey? I guess I'll hang onto my money and see how they fair in the long term...

su27flanker

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

TimD.

My Feedback: (207)

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.

su27flanker

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.

TimD.

My Feedback: (207)

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.

Parkfley1

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.

badangle

My Feedback: (1)

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

su27flanker

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.

badangle

My Feedback: (1)

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???

su27flanker

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.

marksp

My Feedback: (9)

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!

marksp

My Feedback: (9)

Here's my 5-250 on test stand



Looks great! Runs great! Sounds great!

David Jackson

My Feedback: (15)

Marksp,
Just wondering if you have any additional comments regarding the performance of the UMS 250 radial engine. Thinking about this engine for a new project.

marksp

My Feedback: (9)

Still running fine! Starts easy and runs well. I did add a fuel pump setup exactly like my Moki. Not certain I actually need it but feel better having it.

it’s pulling a 55lb 3.7M PZL-104 Wilga spinning a 34x14 scale Wilga prop - great setup!

Here’s a link to another 260

DaleD

Good morning,

As a newby to 4-Stroke Radial gas engines I have been searching with the hope that I would find reading material on the dos and don'ts of their operation. The kind of information that is available in the Newbie to Gas General Information Thread which to my disappointment does not make specific reference to 4-stroke radial engines. Is it that the VERY same principles that work for 2-stroke single/multiple cylinder engines apply to 4-stroke engines?

Asking kindly to be pointed in the right direction or provided with basic operating, trouble shooting and dos & don'ts type information so I can avoid committing user induced sins on my newly acquired engine.

Thanks

DaleD

marksp

My Feedback: (9)

Here’s my program (applies mostly to engines with exposed rockers):

Post flying session maintenance:
- clean and lightly oil the rockers
- clean push rod ends
- clean valve stem, or squirt with TriFlow/WD40
- lube the exhaust valves

After every hour of run-time:
- check/adjust valves

Austars

Good weekend Guys:
The engine is approved. Many sold in Australia with excellent factory service if you need. In the States, you guys can contact Adrian from CH Ignition. Spare parts cost is very reasonable. There are many videos on youtube to watch.
There are few new models coming UMS 5/150CC, 7/360CC
Their full range engines: 5/55,5/75,5/100,5/125,5/150,5/180,5/210,5/260, 7/99, 7/160, 7/260 (REPLACED BY 5/260), 7/360, 9/115

Cheers
Team Austars Model austars-model.com

n8622t

My Feedback: (8)

I have two Evolution 7-160cc and they both have had similar issues. I also have a third UMS 7-160 which is built differently from the evolution versions and has had one issue with the ignition. Adrian with CH Ignitions has sent a replacement ignition which should fix the problem.
I also have a UMS 5-125cc which has been flawless. In addition I have a UMS 5-180cc and UMS 7-90cc both brand new in the box.
I've been quite happy with the engines in spite of the issues with the evolution versions.

n8622t

My Feedback: (8)

Original ignition is history!!!

DaleD

First run of my UMS 5 75 today.


She’s paired with a Gilmore Redlion Racer from Motion RC.

Awesome aftersale service from Adrian at CH-Ignitions.

DaleD

karolh

Hi Dale, that's a great looking model / engine combo with a wonderful exhaust sound. She looks like she is almost ready for the wide blue yonder, and I do hope that you will have many enjoyable moments flying her.

DaleD

Thanks for dropping in and sharing your thoughts Karol. This build has been slow and deliberate. While I’m looking forward to getting her complete and in the air, I’m taking my time.

See you soon my friend.

DaleD

n8622t

My Feedback: (8)

DaleD

That UMS is butter smooth.

DaleD