The UMS 9-115 is a very reliable radial engines which uses gas fuel. UMS has a ton of experience building radial engines. It has brought more than 2000 engines to market so far. The design and construction are upper class leading to a outstanding realibility of these engines. They are easily servicebale. All critical parts are easily accesisble.
- 9 cylinder radial configuration absolutely stunning looks and realism
- 115cc displacement perfect for scale project
- Comes complete with exhaust collector ring,spark plugs,electronic ignition, and engine mount ready to run
- User-friendly choke and throttle bell cranks included makes installation and operation easy
- Made from aluminum or bar stock where appropriate and CNC-machined accurate and repeatable specifications each and every time
- Cylinder head and crankcases produced from aircraft grade alloys
- Heavy duty double bearing crankshaft
- Billet aluminum pistons and hardened steel rings
- Hard chromed and lapped cylinder bores
- Hardened steel cams
- Burns 87-110 octane gasoline with 32:1 gas/oil mixture
Specifications
UMS Gas Radial Engine Manual 9-115

| Standard | Metric | |
|---|---|---|
| Type | 4-Stroke Petrol | SPARK IGNITION |
| CYLINDER | 9 (ABC TYPE) | 9 (ABC TYPE) |
| CAPACITY (CU. IN) | 9.7 | 90CC |
| Bore | 0.98″ | 25.1MM |
| Stroke | 1.02″ | 26MM |
| Thrust* | 27.5lbf @ 24×10 Menz prop. | 12.5kgf @ 24×10 Menz prop. |
| Power (HP) | 7.6 | 7.6 |
| Rotation (RPM) | 1000 – 6000 | 1000 – 6000 |
| Weight | 7.7lbs | 2.8kg incl.(silencer ) |
| Engine Diameter | 10.2″ | 230MM |
| Engine Length | 6.7″ | 170MM |
| Propeller** | 24×8, 24×10, 24×12 | 24×8, 24×10, 24×12 |
| Muffler Type | Collector Ring | Collector Ring |
| Plug Type | 1/4-32 RcExl | 1/4-32 RcExl |
| Carburetor | WALBRO WT-621 | WALBRO WT-621 |
9-115CC 9CYLINDER TECHNICAL SPECIFICATION






Bill Fischer (verified owner) –
Great engine, had some setup issues on my end that Adrian was absolutely the best on walking me through to correct. Started with a recommended prop of 20×9, found it was revving to high at 6700. 700 rpm higher than recommended. Settled on a 27×10, now runs at 5400 rpm. Thanks Adrian!