OS Fs 91 Surpass. Test Run After Service.

Here is another example of an engine that was left for a long time without after-run oil. Disassembling the engine is then always a challenge not to damage anything for all is glued together and stuck with dryed-up oils. I could see that this is an old but still new engine with very low run time. After cleaning I only had to replace the bearings and O-rings. The test runs were done with 10% nitro fuel that I mixed myself with a 50/50 mix of caster oil and synthetic Aeromot oil. 20% oil to methanol ratio. Master Airscrew 14x6 Prop.