Av8r_Sed

Oh go ahead and post a couple of pics to prime the pump.  We all need stimulation.

She did say "Once in a Lifetime".  Too bad!  

I love to see those positive news stories.  Steve K does a nice job of spokesman.  Who's that nut waggin his wings though?

 I do think there's a sometimes unstated deal that if you're going to fly a two-stroke, you have to learn a lot about them.  My first years of flying were in 152's and 172's at FBO's and a flying club.  I learned next to zero about their powerplants.  It wasn't encouraged and it wasn't necessary.  This may carry over to folks who purchase ready made LSA's with 912's and similar.  Many of these just need their annual and regular oil changes and away they go.  If they avoid the low RPM gearbox chatter area, they'll probably have a good experience with little in-depth knowledge.

I can't imagine trying to fly a two stroke that way, it just wouldn't work.  I'm not unhappy with mine, but I've still got a bit of climbing to do on the knowledge curve.  I'm just over a hundred hours on my 582 and it hasn't burped. farted or gone silent on me while in the air.  I'm building confidence with every flight.

I'm going to do the pneumatic balance then look into the gearbox if it's still rough.  First though, I've got to replace the original throttle cables which are anything but smooth even though I've lubed the heck out of them.

Doug, no rebuild on the gearbox. I had it apart earlier this year to replace the rear oil seal and didn't notice any issues. Are you thinking bearings? Any good way to check?

Bandit, during the summer I was running a borrowed Ivo 3 blade ultralight ground adjust and it was smoother, but I still couldn't dynamically balance it. The guy I borrowed it from said he had it nicely balanced. Jury is out on the 2 blade medium but I should be able to get it balanced somewhat.

OK, It sounds like the consensus is to try to sync the carbs, especially at my target RPM.  I've got a plastic U tube water manometer set up that I can attach to the unused (and normally capped) primer ports on each carb.  Will this do the same job as the CarbMate?

I have a problem with vibration on my grey head 582.  It has never run very smooth but recent attempts to dynamically balance my prop lead me to believe I have a rough running engine that needs to be addressed before I can properly balance the prop. My goal is to get it smoothed out at 5800 RPM so I can balance the prop for cruise.  I'm looking for help getting to the bottom of the issue.

I've tried both a Dynavibe and an ACES ProBalancer and I get average readings of around 0.70 IPS and the phase tends to wander around a bit.  Worse, as I've tried adding test balance weights, the readings don't improve much and certainly don't converge.  The vibration sensor is mounted firmly to the top of the gearbox in vertical orientation using a steel plug threaded into the gearbox vent hole.

Symptoms:

- It can idle between 1600 and 2000 RPM.  The RPM tends to wander and it doesn't purr like a kitten.  I've always thought that with no load due to the clutch at idle it will always be a bit rough, but maybe I'm mistaken.

- Seems to make good power.  With the ground adjust I can dial in the 6300 static RPM no problem.

- RPM always seems to wander at a fixed throttle setting.  If I'm targeting 5800 RPM static it can vary from 5730 to 5860.

- Vibration levels seem to vary over a fairly short time span.

Engine: 582 model 90, C 3:1 Gearbox, RK400 clutch, oil injected, 105 hours TT, rebuilt by L.E.A.F. about 4 years ago to meet Rotax time limits.

Carbs: dual Bing54 with HacMan system installed, choke installed and no primer

           everything clean - no debris, newer style floats and proper float level verified, mechanically synced

           idle jets: .45

           currently running .190 main jets with needle clip in 4th position (bottom) HacMan allows me to dial in 1150 EGT at 5800

Mounts: Side mount system with Lord 150PD-30 replaced 3 years ago and torqued down pretty tight.  The rubber seems pretty pliable because I can easily deflect them up and down by pulling on the prop hub.

Instruments: MGL E1 monitor for RPM, EGT's and water temp.  Also TinyTach for RPM which tracks the MGL readings.

Prop: 70" 2 blade IVO medium ground adjust for now, soon to go to IFA.

Ignition: Standard Ducati CDI.  I do have the ignition wired to an ACS key switch instead of the individual toggles.  

I feel your pain. On my field the only other two strokes are on the weed trimmers. Even the powered parachute guy is running a 912. At least the other guys are a little jealous that I get to do my own wrenching.

Congrats to you and your honey, Leni.  She's really cute.  How long until her first fishing trip?

From an older article my Mike Stratman: "Good compression should read between 100-120 psi in both cylinders and 

I put a piece on top and bottom, stuck together in the gap.  It makes sort of an H shape.  It doesn't cause a bend or disrupt the airflow with the elevator up or down.

I've been led to believe that a water jet can cut the type of plywood for our ribs.  Do you have anyone in your area with a CNC waterjet?

Funny thing is I'm sitting here dumb, fat and happy.  I couldn't tell anything bad was happening.

Don't sweat it Leni,  you're doing a great job and the occasional punk doesn't diminish that.

On warmup, I get about to 185 on the water temp before the thermostat opens.  Then it varies between 170 to 180 while taxiing.  If I do a full power runup (eg when pitching my prop) I can get to 190 before backing down and cooling it off.  In the air I usually run around 170 in the summer.

Forget about CHT on a water cooled engine.  It doesn't mean much of anything.  In the air, I just watch the EGT's like a hawk.  I'm happy to have a HacMan system which allows me to dial in the correct mixture and EGT for most phases of flight.  Before I had that I had to avoid the mid-range RPM settings for the most part.

He's the guy who won it at auction for $15K and is trying to flip it for $22K.  I hope he does sell at that price.  Capitalism at it's best.

A lot depends on the prop you're running and the design and condition of your motor mounts.  2000 should be attainable if your prop inertia isn't too high and the mounts are doing the job.

I got a set of the Easy Thread Bungees from Highwing.  They did go on much easier because of the smaller splices on the eyes.

http://www.highwingllc.com/bungees.html

Did you take apart the carbs?  No junk in the bottom of the float bowls?  Take the carbs off and look through the main jet and you should be able to see straight through.  If it sat with gas in it for any length of time you might have crap built up in there. Old gas, especially auto gas doesn't age well and tends to gel.  Also if you have it apart, make sure it has the newer floats with the beveled edges.

Check out this article for further carb info: http://w.cps-parts.com/cps/pdf/Part52.pdf

I'm running a 45 on my 582, but then I have a clutch and almost no load on the engine at idle RPM's.

Welcome Dave,

Great to have another Avid in the group. I hope the repairs and upgrades go quickly for you. The good flying weather doesn't stick around forever. Any pics of your project to share?

Oh no, I'm not hiding the switch under the hood on my bird.

Thanks guys. I hope to join the IFA club in the near future.

So if I've got a 3:1 gearbox, the prop of choice would be the three blade, 72" standard pitch ultralight IFA? IVO still maintains that the three blade and 3:1 gearbox is a bad combo, knurled hubs or not. It gets a little pricey if I have to pop $500 for a 2,62:1 gear set too. Is anyone currently running with the three blade and 3:1 gear ratio?

My concerns over drawing too much current pretty much went away with the advent of LED lighting.  I converted my position lights with plug in replacement bulbs and purchased a LED landing light.  I have a computer muffin fan on my cabin heater which is pretty efficient as well.