Originally Posted by partshunt

Hi there; If you recall a while back I asked about Minnie Motors. I would like to say, I finally received the UMS 50-7 cyl. I am getting ready to run it and they say use two stroke oil. I have new oil, it is Stihl chainsaw two stroke oil, mix . UMS recommends 32-1 to break. Question, what do you fellas think of using Stihl oil will it be good on the UMS?. I also have a couple jugs of Evolution Oil, being Evolution that should be good as well. Your thoughts and what oil do you fellas use on UMS Radials.. Thank you.

Originally Posted by partshunt

Anybody have experience with Evolution Oil? UMS is supposed to previously be an Evolution radial and this oil is for those engines, it must be ok for UMS I would think. Anybody have bad experiences with this oil?..I have two quarts of it..

Originally Posted by Jaketab

With respect to the oil question on radial engines, I have been running Amsoil Dominator in my 2 Moki 250's at 45/1 and Valach 210 at 32/1. In addition, I use it in the Saito FG90R3 at 25/1. It keeps the piston clean and also has excellent blow-by lubrication which is needed in the Saito. I also treat the fuel to Seafoam fuel additive at 2 oz per gallon. No scorching, burning, or broken cranks in any of my engines - ever.

Originally Posted by Hyjinx

Do you agree the exhaust residue is black and "dirty" with the Amsoil Jaketab? It cleans off easy with tub o towels, but seems really carbon black and slippery too. Very different than Klotz Gas Burner. I am not complaining, just curious. Dr G raves about the product Says it is the best for the internals long term, he has serviced more of these motors than I will ever see.
Wondering if the seafoam is having a effect on the product . I have used SF with Klotz in methanol and gas, but not the Dominator as of yet. I broke my UMS 125 in 32:1 then 40:1 the residue seems the same. I haven't pulled plugs for inspection yet. It runs great and starts really easy, no evident fouling....
Runs really cool too 140-150 uncowled.

Originally Posted by CK1

There's probably a detergent factor that is different among oil brands . The more detergent the more black stuff you see removed from the engine ( a good thing) as it breaks in and from some carbon clearing in the exhaust. The detergent encapsulates the contaminants so they flow out with the expelled oil in the exhaust. Lesser detergents in the oil equates to less contaminants removed and a cleaner exhaust residue .

Originally Posted by Hyjinx

Welcome MateI have a 125 five cyl on a Waco 60 ARF of similar dimensions. Fit in the cowl was a major decisive for me. The Waco ended up at 28 lbs auw and flys well with no weight on the tail. Your short nosed Flair will probably be happy without adding to the tail, but will probably fly well and be a good fit. Won't be lacking power for sure.... Low wing loaded bird anyway, weight in the tail if necessary won't be a deal breaker. Imho.
Aaron-

Originally Posted by Jaketab

"Hi All.
Finally got a nice short vid of the Phoenix rising with the UMS 125. Enjoy!"

Looks like a perfect match for the Phoenix. Nice.
J Tab

Originally Posted by mikes68charger

Help!

I can't decide between UMS 180 or 210.
I'm building a coustom T28 at 114in wing span around 45 pounds I'm hoping.

My issue is I'm limited to a 28in max diameter prop, preferably a nice scale 3 blade.

It seems the UMS site say the 180cc runs a 28x10 2 blade while Belia prop sales says a Moki 180 is suited for there 28x16x3 blade which sounds like a huge load difference.

But all the UMS210 are in the 32in range. But saw a video of a guy rocking the same 28x16x3 blade as a brakein prop but upgraded to 32in next video.

On speck sheet the 180 and 210 look exactly the same except the 180 is .2in smaller which I would prefer but i don't know which is better choice?

Thought?


A trusted full scale plane designer/builder who also builds r/c model assisted me when choosing an appropriate engine recently. I had posed a question on a few forums and was not satisfied with the answers I received. I was under the impression wing loading was a determinate factor. He lead me to believe thrust versus weight to lift was the critical metric. Simply stated If the thrust generated is greater than the weight of the airframe fully equipped. The plane will fly. Greater thrust than weight will fly with greater authority.
I saw we this played out with my Phoenix Waco. The total AUW is 28 lbs. The UMS 125 gas motor generates 32 lbs thrust.
The plane flys with authority at half throttle.
Here is video verificationhttps://youtu.be/res0qG5JelE

one guy told me to get 210 and just limited max rpm on Ground around 4500 with servo, but then would the motor still pick up rom in air?

Thanks

Originally Posted by Maxam

So I got the 5-55 from Adrian 'cause it is cute and a nice small size. Got it mounted up and used a 22x10 prop. The engine can turn it to 4500rpm. True hp at this rpm is 1.5. Sure it can develop more hp at a higher rpm but then much smaller prop. The UMS glow style carb has the classic way over rich condition at mid throttle. The trick of adjusting the throttle mixture at half opening still was unsatisfactory. I made an adapter on the lath for the Saito 90r3 carb and that was the ticket! Beautiful ideal mixture at all throttle settings with immediate response. All cylinders at same temp. A 4oz tank runs the engine for 15 minutes with some part throttle settings. The question now is will the seals in the Saito carb hold up on gas? Reliable idle at 1000rpm

-Tom

Originally Posted by okcrcpilot

David,

I don't have the five cylinder (mine's the 7) but I set the needles to what is recommended in the engine manual. I have never had to adjust them, even after having many flights on the engine.

Gary

Originally Posted by partshunt

Hyjinx, you say in your post you are building a custom T-28. Did you get the plans from a supplier or did you draw up your own plans?. I ask because I like the T28 and flew one of Dave Platts old kits for many years and I still have it. I would like to build another for 50 cc 7 cyl UMS that I recently bought.

Originally Posted by lozza1965

Hi Guys new to this thread but thought I'd share a photo of my Zeroli Stearman with a USM 90cc 7 cylinder in it, had about 15 flights on it now, flying great, only downside is the black deposits its chucks out the exhaust, is this common, hoping it will ease in time.

Originally Posted by SPACE COWBOY

Howdy Friends! I'm thinking about pulling the trigger on a UMS 5-cylinder 75cc radial for my Jim Pepino Lockheed Vega 5B. It has a 100-inch wingspan and I'm thinking it will be just right under my cowling. I've done business with Adrian at CH Ignitions several times, and like him a lot. The same goes for Goetz Vogelsang, as we're practically neighbors. I was considering the Saito FG-73R5, but it doesn't come with an exhaust collector ring like the UMS 75cc engine does. Adrian recommended I buy the UMS. I'm leaning that way. Any ideas, guys? Thanks!