EP 55 How to NOT make a Rotax 2 stroke engine EXPLODE! Challenger 2 Ultralight Airplane

I almost made a HUGE mistake, and thankfully I avoided disaster. Starting of my engine has been delayed for another weekend.
Follow along as I rebuild, repair, and upgrade a Challenger 2 ultralight airplane. Ultimately I will be flying this airplane into the north country of Canada, on fishing and camping trips, as soon as she is ready to fly.
Challenger 2 with a Rotax 503 Engine
Puddle Jumper Amphibious Floats
Kuntzleman Electronics LED anti-collision and strobe lights
GRT Avionics Sport EX EFIS
Radiant Instruments backup Altitude/Airspeed/VSI
Sheer Technologies 17 US Gallon Fuel Tank
Engine Fogging Kit:
www.rotacrepai...
#Challenger
#Flying
#Experimental
#Airplane
#Aircraft
#Aviation
#Ultralight

[@jackryan152]

You are welcome!

[@demonsthenes8228]

Oh my! I would never have thought of an engine "run away". Thanks for the heads up.

[@challenger2ultralightadventure]

Glad to help

[@johnnunn8688]

You’re not going to believe this but when you said you were going to run the engine, sans prop, I was worried but didn’t say anything because I’m not familiar, with this particular system. Glad I was proved correct and glad you spoke to someone first. 👍 TBH, I didn’t know it was a flywheel-free engine, only knew I’d never seen an engine run, without at least a cropped prop.

[@challenger2ultralightadventure]

All engines I've worked on have some form of flywheel, so this was new to me as well.

[@johnnunn8688]

@@challenger2ultralightadventure, as an aircraft (RAF) engine tech, I knew the engines I worked on, didn’t have flywheels, but know nowt about Rotax/civvie GE stuff. Anyway, totes glad it worked out and you didn’t destroy your motor. 👍😀

[@Russellsperry]

I have a 503 Rotax, and I never would’ve thought of that. I sure appreciate the great advice 👍

[@challenger2ultralightadventure]

You're welcome.

[@calmmusicforsleep]

Awesome video! Thanks for sharing! Have a great week my friend!

[@challenger2ultralightadventure]

Thank you! You too!

[@Charles-xq6tv]

the 582 with clutches all run pretty good without the prop spinning

[@challenger2ultralightadventure]

The clutch on a snowmobile engine is a good flywheel.

[@FourthWayRanch]

@@challenger2ultralightadventure he's talking about the centrifigal clutch on some aircraft gear boxes and he's right, there's no effective flywheel in these setups so I don't know what these guys are talking about with rotax runaway. I ran mine last night without a prop on it with no issue.

[@markpacey1009]

Sorry. You need to get the pulse pump close to the engine so the pulse line is as short as possible. Have a look in the Rotax manual.

[@av8tor261]

Also the type of pulse line is very important. DON'T USE FUEL LINE!

[@jimboagogo]

Looks teal good with the prop in place! Wings next?

[@challenger2ultralightadventure]

A few last bit items, then an engine start and tests before the wings get put on. It will be easier to test the engine without the wings on, rolling in and out of the hangar.

[@thecottonpatch80]

Great Video. Glad we all saved your engine. Sean is a great guy and good friend. Will you be flying before the cold sets in?

[@challenger2ultralightadventure]

Thanks to Sean for his insight! Flying this fall was in the plans, but I'm seriously doubting it now. Very disappointed by that. But that's life.

[@philbrookman3126]

Great vid... Ur mikuni pulse pump. Should b very close to engine.. There is a max distance... And use a stiff pulse line.... Also did u track the prop... I am currently using a lecy pump inline with mikuni... But working on a system where there are 2 pick ups in tank and a few one valves.. Also u should have fuel line pressure guage in cockpit.. So u can see what's going on

[@philbrookman3126]

Which also means to b quick to shut down engine.. After a prop strike

[@FourthWayRanch]

I've run my engine up without a prop on it no prob, maybe people didn't have their carbs setup properly. should be ready on the kill switch when startup up unknown engine anyway. Why is this not an issue then on the gearboxes with a clutch??? The clutch will kick in and slow down the engine?? if so then why don't we hear about this happening all the time? I'm skeptical. if you search the skidoo threads people talk about not running without the clutch either, maybe it's best not to diesel engine runaway is a common hazard in the oilfield but that's from crude vapors getting in the intake

[@challenger2ultralightadventure]

The “strong” advice I got from both rotax service centres, is not to run the engine without the prop. Engine run away would destroy the engine faster than one could react to shut it down.

[@FourthWayRanch]

@@challenger2ultralightadventure I wonder what kind of damage would happen that you could see.

[@philbrookman3126]

also ihope that was a calibrated tourque wrench as i nearly trashed an engine using an uncalibrated one another lesson for me

[@johnnunn8688]

Good to see the subscribers 🛗😊.

[@challenger2ultralightadventure]

me too!