Good News!

In my previous blog entry I wrote about my engine woes.  I sent the photos to Rolando Santiago at Six Chuter who took a look and informed me the piston was toast.  He and Doug Maas consulted with J-Bird Engines (the engine manufacturer).  J-Bird asked for the engine to be sent to them so they could take a look.  To their credit, the guys as Six Chuter paid the cost to ship the engine back!  Once the engine arrived, the guys at J-Bird knew exactly what happened.

You see, there are exactly two belts on this engine.  Both of them are fan belts… more or less.  One belt is on the rear of the engine and connects the crankshaft to the propeller.  It reduces the RPM of the propeller because the prop isn’t designed to turn at 6500 RPM.  The other fan belt turns an actual cooling fan at the front of the engine.  Now there are sections in the engine manual that describe tightening these belts.  I dutifully checked the belt tension on the prop, but missed the huge page in the manual saying how important it is to adjust the tension on the fan belt!

When J-Bird dug into the engine the first thing they noticed was how loose the fanbelt was on the cooling fan.  And yep, the front piston was in the worst shape.  Problem found.  The engine was overheating due to poor cooling.  Totally my fault.  But here is where the AMAZING customer service part of the story comes in.  I was told the engine would be rebuilt at NO COST to me whatsoever.

Now, gentle reader, I don’t know how much you know about aircraft companies but Six Chuter is an anomaly in aviation.  Most aircraft companies would have said “Uh, user error, you need to pay the cost to fix your engine.”  Six Chuter did not do this because they believe in their products.  They stand behind their products and the components that go into their products.  Six Chuter is run by people of integrity and truly believe they are held accountable to God for everything they do on this earth and it shows.  I cannot say enough about this company.

So back to the engine.  They are going to rebuilt it from the crankshaft up and it should hopefully be shipped back to me next week.  I’ll post more updates on the re-install and next steps on the engine when I get it back.


Bad News

Friday I was testing needle placement and prop spacer blocks on my P3.  I did a warm up and then a simulated takeoff and throttle back to cruise to see how my throttle response would be.  Everything went well until I throttled down to cool off.   It ran for about a minute then RPM started to slowly drop until the engine died.


I let the engine cool down and then tried to start it again.  It would not start even after several attempts.  I scrubbed the morning’s flight and headed home.   The next day I called factory support and he walked me through several steps to try to get the engine started.  Nothing worked.  Even spraying starter fluid directly into the carburetor would not get the engine to start.   We verified that the spark plugs and ignition system was working, we verified fuel flow, all to no avail.

Their engine guy asked me to check one more thing.  He had me pull the muffler and exhaust manifold and check the pistons.  It was not a pretty picture.

I’ve sent the pictures to their engine guy and their chief and we’ll just have to wait and see what they come back with.  I really don’t want to tear into this engine, I’m not a mechanic.  So rather than going to the High Sierra Fly-in I may be going up to their facility to see if they can help me out.

Morning P3 Test Flights

I’ve been doing lots of tweaks and testing of my engine on the ground but haven’t flown it much.  I changed that this past Friday and Saturday mornings.  Friday morning I flew with the 10 degree prop blocks.  These set the propeller pitch to 10 degrees.  I found that throttle response was good but because of the fine pitch of the prop climb rate was reduced and I found myself at almost 6000 RPM just to maintain level flight.  That only gave me a couple of hundred RPM more to climb with.  Not a good feeling.  Also the engine cylinder head temperatures were running too high at 400 degrees.  Even worse feeling.  However throttle response and smoothness were much improved as was exhaust gas temperature.

Friday night after work I put the 11 degree prop blocks in.  I test flew these Saturday morning.  In all honesty I didn’t notice much difference in the way of climb performance but CHT was lower which was good and EGT was also lower which is very good.  I did notice a little ‘bogging down’ of the throttle in one particular RPM range but it wasn’t too bad.

For next week’s test flight have have moved the carburetor jet needle to the number 2 position.  This will make it run slightly leaner which may cause EGT to rise.  I’ll have to watch that.

Because there are so many parameters to change it’s all started getting mixed up in my head.  To that end I’ve started a spreadsheet to track and measure all my changes.  I should have done this in the beginning.  I’ll put the link below in case anyone is interested.

I’m also going to take a page from one of the blogs I follow.  He always leaves a song linked to the end of his blog.  I like the idea.  So cruise on into your Sunday evening with the smooth sounds of Tom Middleton…

I Think We’re About There

So the last two weeks there has been little in the way of flying and a lot in the way of carburetor tuning.  We’ve been tweaking jet needle settings and even replacing jet needles but the one change that seems to have worked wonders is repitching the prop.   Six Chuter sent me two more sets of prop blocks to repitch my prop.

The blocks are basically triangular blocks of carbon fiber, similar in appears to a door stop – sort of shaped like a right triangle.  The long edge is precisely set at a particular angle.  You wedge the prop between two of these blocks and then place it in the propeller hub and that sets your blade angle.

The current spacers I have are set at 12 degrees.  I tried the 11 degree blocks but that didn’t seem to make any difference.  When I put the 10 degree blocks in I got much better RPMs and cooler temperatures, so much so that I put my original jet needle back in and back at it’s original setting.  I’ll try a test flight on Saturday morning and we’ll see how it it works out.

P3 Lite Carb Tuning Continues

I took the test flight I wrote about in the last article.  I had moved the needle clip to the top-most position on the needle, effectively leaning the mixture.  The resulted in PERFECT throttle response.  However, it also resulted in much higher engine temperatures.

No bueno.

I spoke to the folks at Six Chuter again and they are going to send me a different needle for my carburetor.   They are also going to send me some new pitch blocks for my propeller.    They believe the prop may not be allowing the engine to turn as fast as it should.  I’m only getting about 6100 RPM static.  They believe it should be closer to 6500.  I’ll be trying the new spacers which will allow the prop to spin faster.  This will cause the engine to work less hard to spin the prop as well.  I’ll do another test flight once the spacers come in.  If the spacers don’t correct the heating problem then I’ll try the new carburetor jet needle.

Six Chuter has been very responsive and I appreciate the factory support I’m getting.  Great company!

P3 Lite Carburetor Testing / A Name

I have been having trouble with the throttle response of my P3.  I called the factory support line and talked to their engine guru.  He suggested that I run the P3 on the ground, throttle up until I get into the problematic RPM range, and then give it a little shot of prime.  (The primer shoots gas directly into the carburetor and is generally used only during starting.)  The thought was if I gave it some prime, and then engine bogged down, then I’m running too rich, if the engine revs up, then I’m running too lean with the stock settings in the carburetor.  I tried the test and it bogged down big time.

Six Chuter factory support recommending I change the clip position on the jet needle.  With out going into carburetor theory the jet needle controls how much gas the carburetor delivers to the engine.  Moving the clip up makes the engine run leaner, moving it down makes the engine run richer.  I moved it down first, and the problem became worse.  I moved the clip up and throttle response was good throughout all RPM ranges!

I did have a momentary scare when I saw that there was a split in the clip on the jet needle.  I had never noticed it before but was assured it was completely normal and was part of the design.  Six Chuter factory support assured me this was normal.  And a friend of mine who has an extensive ultralight history assured me this was normal.  In fact, he sent me an article by Chris Wolf on rebuilding the Bing 54 carburetor which has this excerpt:

If you look closely at the E CLIP, you’ll see that it has a break in the
metal, right next to the curved part of the clip that snaps around the body
of the JET NEEDLE.  This is as it should be.  Rest assured that you didn’t
break the clip when you pulled the JET NEEDLE out of the piston.

Well that’s exactly what I did.  I dropped the clip on the ground and thought I broke it!  So glad Jim Volk sent me that article.

Now that I have the carb adjusted properly I’m going to give it a test fly tomorrow and see how it works.  I’m hoping this cures the problem and I can start working on my landings again.

A Name

I’m not big on naming inanimate objects.  I’m not good at it.  However, when a fellow P3 pilot suggested that since I used to work right outside the gate to Moffett Field and I had P-3 Orion Sub Hunters flying overhead all day, and since I was working for the company that manufactured these airplanes, Lockheed, that I call my P3… Orion.  And a name is born!  This same fellow also quipped that I should check the belt drive on the propeller from time to time, as he put it, don’t for get to check Orion’s belt!

P3 Lite Status Udate

Here’s just a quick video with a status update on my P3 Lite Powered Parachute from Six Chuter.  Still enjoying this little beast.  Have worked out a couple bugs and have just one more to go.  Great little machine!