I'll probably add that fairing to my tubing as well.
As for the ignition: Is it a completely unreasonable idea to drill and tap a new hole on each head (they are very thick, I don't think strength will be a worry) and add another set of spark plugs and tie another CDI coil pack onto the system? I already have redundant fuel pumps.
Could it be done....possibly. But it would be so much easier, quicker, and likely cheaper to just sell your engine and buy one with dual ignition.
It's actually a snowmobile engine, a Kawasaki 440A, converted for aircraft use by J-Bird
He told me that they've never had any of their CDI units fail in the air that they've sold, but.. Knowing my luck I'll be the first, lol.
I once had a Kaw 440A on a CGS Hawk. It didn't fail while I had it but the guy who bought the plane had a failure on takeoff shortly after he got the plane. Like they say, not if, but when.
No. Drilling the head is a dumb idea because the flame front that regulates the combustion pressure is changed. No. Drilling the head is a dumb idea because there is a risk of creating hot spots that melt pistons. No. Drilling the head is a dumb idea because there is a certain amount of engineering work to do that weakens components, risks burning pistons and adds weight without improving performance.
It would be possible to add a pickup to a 447. It is also possible to use 503 heads to convert to twin plug. But you will need to power the new CDI module and that means you will need a 503 stator as well. In fact the only bit of a 503 you will be missing is the increased capacity so it simply is not worth the trouble.
We risk the 447 with its single ignition because any engine can fail and the 447 is pretty good. If you don't want that risk, you could buy a 503 which can also fail or choose a different aircraft. Mostly though, practice your PFLs and always have a field in sight.
Fair! I was thinking about the hot spots and combustion pressure issues. Probably not worth it. The CDI box on the 440A seems very reliable from what I can tell, so... Just up to me to really keep an eye on it, and keep fields in sight!
It's actually a snowmobile engine, a Kawasaki 440A, converted for aircraft use by J-Bird
He told me that they've never had any of their CDI units fail in the air that they've sold, but.. Knowing my luck I'll be the first, lol.
I have experimenter 1989.There is a 2 stroke engine survey which was done in the early days of ultralight aviation.
There is mention of Kawasaki 440 engine.I dont know if its an A or a B.It just says 440.
It says( the kawasaki 440 seems to be the real sleeper engine,It has shown few internal problems and has a reasonably high MTTF. out of 125 engines surveyed 8 are kawasaki 440 and there are 5 failures.All are spark plug failures.
that is fascinating! When you say 5 failures, do you mean of the 440, or in general? And if its just plugs fowling and getting worn out, that doesn't seem like it would be so hard to deal with, just have a regular inspection and replacement schedule for them.
LSaupe, I'm OK. Still sore. With help I got I got it home today, but haven't had a chance to investigate a cause. It does appear that it didn't seize. Damage appears to be a crushed lower nose, crushed top of the fuselage where the roll over bar is (windshield bow), and some damage to the top of the vertical stabilized. Certainly an easy repair. I didn't have any choice, except to go straight ahead, which meant landing in a wheat field. My son-in-law, and my grandson took a couple of pictures, and I might try to post them, but basically it's Mini Max 1030 on it's back. you can pretty much in-vision it for yourself. The wheat was browned out, and there was no plan to harvest it. It was a winter cover crop that will be plowed under.
No. The starting problem had been solved. Patience. Inspection and test equipment together with a methodical approach will be many times more effective than ill informed guesswork. There isn't a prize for best guess. I shall analyse the engine's systems as follows: rotate prop. Proves compression on both. Remove float bowl which had fuel in and check float needle moves freely. Check security of the leads and plug caps. Check security of ignition leads. Remove plugs from engine and inspect. Disconnect stator and pickup. Measure insulation resistance to ground. If no clues, remove manifolds and to check rings have not stuck and then heads to ensure no seizures or burnt pistons. Check pisto[b][/b]n crowns for carbon buildup that might have come adrift and fouled plug. You see? Order, method, measurements. Many years of test engineering gives me the skills to get to the most certain cause - guesswork can be fatal.
There's the correct way to diagnose and repair a failure and there is also the intuitive way.
In my experience of repairing multimode multiband HF radio sets there had to be a balance between gut instinct testing and methodical testing. That's because I was spending the customer's money. I felt I had a responsibility to reduce that time/cost even though it may have reduced my employer's profit.
My point here is that intuitive testing/action can be informed by knowledge and experience of a particular technology and can save a lot of time/effort/money. Not everybody is used to correct fault finding procedures. Forums like this can be a good addition to guiding the intuitive fault finding route before the full horsepower of methodical method is used.
Intuitive is not the same as guesswork. If you were in the cockpit at the time you felt the engine and heard it. You can fuel your intuition with data. Without any supporting information any diagnosis is a blind guess. An intuition that the rf amp is down because the set is deaf is usable data and that makes it easier to find the fault.
Looking at the published chart you quickly understand why flying with a two stoke engine nearly guarantees an engine out landing. The total of all engines reported is 125 with 83 failures at an average time of 63 hours!
Note that for non-failed engines the highest time in service was only 200 hours.
I think I'm reading that right! Seems like it ranks up there with the best of them! Glad to see this, thank you!
Don't read too much into the 440 numbers. Yes, only 33% of them were reported as failing, but the average hours was only 20. It's likely that as more hours were flown the failure rate increased to match the other engines on the list.
If I have any one concern about the limitations of the Part 103 category in the US, which is a tremendous boon for people with less money and who perhaps are older, it is that it is difficult to do a really "aircraft like" ultralight which uses a 4 stroke engine. It can be done, but the number of designs which can do it is fairly small. I do suspect that a little more advanced work on combining wood, epoxy, and carbon fiber can sufficiently lighten an ultralight like the Mini-Max type to make it a more straightforward proposition to keep within the weight limits with a 4 stroke engine. Also the more you think in terms of "motor glider" the more it probably makes sense.
If a thousand engines fail out of a thousand, that it one thing. In a million it is something else. These figures are from somebody with an axe to grind against two strokes. Mine failed at 200 hours, almost certainly Ducati's fault, not that of Rotax. I have yet to see a four stroke that works as well as a 447. I'm out looking at another aircraft this weekend - 600 mile round trip on a public holiday in a peak tourist spot. Doh! It will be fitted with a Rotax 503.
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