OS Hyper

This engine loves to eat bearings for breakfast and piston for lunch. However, unlike my previous Thundertiger engines, I found that having a plug life of 5 or 6 gallons is pretty common. I never really felt that it was a lot more powerful like everyone else is claiming until I upped the headspeed and got the hatori 522 muffler. The 60L carb is really large for an engine this size and it sure drinks for its size. The 330cc tank on my raptor only last for 8mins flat from full to header. Its an amazingly good engine not because its extremely smooth or powerful, but because it just continue to run and idle well no matter how badly it is tuned. It could idle well even when I was just running in pretty rich.

I was getting around 5-6 gallons per rear bearing. I went through 3 piston and rings. First 2 lasted 11gallons each while the third one broke after 5.5gallons.

I recently replaced the ring, piston, cylinder liner and con-rod after the 3rd ring broke. 28gallons wore out my con-rod slightly, not a lot, but it was cheap, so I replaced it for a peace of mind. My cylinder liner got scratched slightly, so I got it replaced too. Why not replace the whole engine when the price to repair is more than half of a new engine? Because I am still waiting to for more flight reports on the new TT redline engine and so there is no point in buying a brand new hyper and just use it for a few gallons.

New vs Old. Note the finish on the new liner. Its suppose to look like that, a bit rough and honed to help the new ring to bed in.

28 gallons haven't worn the con-rod a lot, but replaced it because there was a bit of free-play.MY new hobby-Collecting pistons :( :(

Praying hard that the new piston and ring will last me till I get the redline.