This may never effect you but . . .
Something else to think about. About 2 years ago I ran into an issue in flight where I felt there was a very slight stumble in the engine. I'm talking about flying along at 2350 happy as can be with my RV Grin fully engaged
then all of the sudden like a hiccup that lasted 1/100th of a second
what was that.
Then the fun starts, check fuel selector, fuel pressure, engine gauges, mags, etc. Well EVERYTHING is running great, not sure what that was but wondering, Will it do it again? Some time later. . bam - again a hiccup. Then it's "okay, it's time to get on the ground and figure this out".
I'll try to cut my story short because it lasts for 2 years!!! I have had 3 very well respected mechanics look at it over the past 2 years and have done the following to the plane because we couldn't replicate the issue at will.
First round we checked everything from plugs, to mags, to wires, timing, carb, fuel flow, fuel lines, fuel vents, induction, you name it....
- 1st so called fix- We thought the alternate air door that is magnetic was loose and the turbulence may have opened it just slightly providing a rush of air into the carb for a split second. So we adjusted it to be tighter. Flight test for 30 minutes and seemed to fixed the problem. several flights later (2 to 3 weeks later) bam
same issue, turn back and find the issue.
- 2nd so called fix - Okay, let get serious now, Alternate air? come on! I'm sure it's has something to do with spark. Clean the plugs again and retest. This time spoke to several folks on this forum that told me about the Champion OHMs issue so I took out my $90 fine wire plugs and replaced them with Tempest. Once again tested the wire, the mags seemed to be testing good. Test flight showed to fine but guess what.... 2 weeks later while heading to a Saturday breakfast bam it hiccup again
- Back to the drawing board - It's gotta be the mags, although they only have 230 hours on them, take them out send them to Magneto Services, take out a second mortgage on the house to pay for all this and guess what.... same thing happened on a flight to Florida because we couldn't replicate the issue during our test flights.
- Now this is just getting silly because by now I've had several conversation with some really smart people about this and at least 2 very respected mechanics are stumped. Well, maybe it's the carb float ... don't think it is but just maybe. I hate being unsure about my engine so at this point I have an attitude of "I don't care what it costs, I want this fixed for good so I can fly with confidence".
Okay let's buy a new carb and eliminate that as a problem. Great !!! let's throw some more money at it. While we're at it let's change the wires and leads so the electric and fuel possibilities are eliminated. We also checked fuel flow again and vents, etc.
Well I'm going to stop listing all of the things that we ended up fixing/replacing because there is more but after 2 years one of my friends who is also a mechanic for over 20 years said, lets disconnect the ignition switch and see what happens. I thought, that's odd... what the heck does that have to do with it. I have an ACS keyed ignition switch with a OFF/L/R/Both placements. So he disconnected the P-leads and I went flying. We did this for over a month, over and over again, and decided the issue all along was in fact the contacts in the ignition switch. We concluded that during flight for some reason at any given time (maybe the vibration) the contacts inside the switch would lose contact and it was like turning off the ignition switch in flight and turning it back on at lightning speeds. I spent well over $3000 chasing down this issue which turned out to be a $16 dollar fix, essentially changing the contacts inside the switch with a $16 dollar kit.
Now I'm flying with my RV Grin ON again
for the past 4 months and no engine hiccup and feel great about it. I'm an optimist so I look it as I have new parts on my engine and getting better "gas mileage" because my wallet is much lighter