F33 Hirth Engine Manual
F-33 2 cycle 28hpOne little powerhouse of an engine. At only 35 lbs. This is one of the lightest singles you'll find anywhere. Of torque, this engine packs enough punch to spin up the large props on your backpack parachute, tryke or legal 103 ultralight. Factory recommended TBO is rated at 1000 Hrs. Standard equipment includes fuel pump, spark plugs, air filter, recoil starter, complete exhaust system and dual CDI ignition for added reliability. When ordered with optional electric start the starter solenoid and voltage rectifier/regulator are included.
Standard mounting is plate type from bottom of engine. An optional crankcase allows 4 point mounting (firewall forward style) from the ignition side of the case instead of from the bottom of case. This option must be special ordered and adds 2 pounds to total weight. Engine pictured above is equipped with the forward style mount, electric start, and belt drive mounted in the hanging position.
I just received a September copy of SPORT AVIATION, in which there is an excellent article regarding the Aerolite 103. As I have become frustrated with the Sport Pilot licensing route, but still enjoy flying, this presents new possibilities. Maybe I'm falling prey to the hype, but this one sounds good. It can be a kit or complete, and standard comes with a Hirth F33 2-stroker. My question is, how reliable is this engine?
F33 Hirth Engine Manual Diagram
In the '70s I grew up with 2-stroke road and dirt bikes, and found those (Yam and Zuki) to be strong and reliable, although smoky. Plugs fouled regularly, and exhaust ports needed to be cleaned now and then, but sooo easy to work on, not a problem. Get the oil mix right and keep the revs inside the redline and everything worked fine. Research on the INET produced very little useful information; a few swear by them, and just as many swear at them. Knowing the frustrated are more likely to sound off than the satisfied, I'm asking any and all to respond with info, facts, or anecdotes regarding the Hirth aircraft engines, especially the F33. I read the Aerolite article too and was impressed.
But I think chicagorandy's response is the best idea.Keep in mind that aviation and marine use involve mostly steady throttle/rpm conditions which add a lot to reliability. Aircraft mechanics I have talked to feel that if you stick to the maintenance schedules for them, 2 cycle engines are reliable. (I have never flown one)The other important thing is your attitude. If you are casual with preflight and before flight testing indications, you should go back to dirt bikes. Also find yourself a grass strip and keep up practice for engine out landings. Plan your flight route, even a fun hop, that keeps usable landing spots under your tires.Keep us updated on your research and progress.
HAPPYDAN wrote:So I'm intrigued and inspired by the whole 'Part 103' aspect. I guess the NTSB and the FAA doesn't really care if I endanger myself, so long as I don't endanger anyone else.
But this old dog knows that advertising 'hype' can cover up a lot of defects, hence my concern. U-Fly-It (current builder of the Aerolite 103) offers several engine options, and I wouldn't mind paying a little extra for a solid mill.Usually, you people complain about over-regulation by the FAA. I think this is the first complaint I have seen on one of these aviation sites about under-regulation.
It never stops. HAPPYDAN wrote:So I'm intrigued and inspired by the whole 'Part 103' aspect.
F33 Hirth Engine Manual For Sale
I guess the NTSB and the FAA doesn't really care if I endanger myself, so long as I don't endanger anyone else. But this old dog knows that advertising 'hype' can cover up a lot of defects, hence my concern. U-Fly-It (current builder of the Aerolite 103) offers several engine options, and I wouldn't mind paying a little extra for a solid mill.Usually, you people complain about over-regulation by the FAA. I think this is the first complaint I have seen on one of these aviation sites about under-regulation. It never stops.I didn't take it has him complaining.