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Putting the "adventure" in AirVenture

panhandler1956

Well Known Member
I had great time at Oshkosh! The RV Social was a blast, the RV Banquet was great, I met a lot of excellent people, and saw some cool machines!

I packed up to leave Wednesday mid-morning. All was fine with the world until I pushed out of my spot at Homebuilt Camping (HBC), hopped in my bird and went to start it. It fired off and then died. Then I managed to run the battery almost dead trying to get it to start. I've never had starting issues, but I've been tinkering with my idle mixture (Bendix FI) and think I have it too rich.

Long story short, we managed to get it started, but it definitely added some unwanted "adventure" to AirVenture.

I wanted to thank the other RV'ers who helped me, of course I can't anyone's name:

1) Push it in-and-out of the aisle several times for start various attempts

2) One RV-8 builder (Jim from Dallas) who helped me uncowl and inspect it, and

3) the EAA Volunteer who did yeoman's work helping jump start it and get me out of there! He had to pull the cables and reload my rear bag (battery in the back) after it started (luckily I have an access door, so no removal of the baggage liner was necessary).

I stopped in MKE to pick up a buddy who needed to drop a rental car. The trip home to Ohio was uneventful on top at 12,500 getting in just before the weather.

Gotta love it! Can't wait til next year!

Here's some of my pics from the Show.
 
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I saw you cranking away while I was pulling mine out. Glad to hear you got it started cause it looked like you weren't having fun.
 
It fired off and then died. Then I managed to run the battery almost dead trying to get it to start. I've never had starting issues, but I've been tinkering with my idle mixture (Bendix FI) and think I have it too rich.

Just like landings, never goes just perfect when you got a crowd watching.

I had the same issue this morning with cranking the battery dead but I was doing a hot start down in Mattoon IL 100 nm from home. I have the Bendix FI as well. Never had a problem with hot starts until the last few months. Now I can't get it started at all when hot. Today the FBO charged my battery as I waited for a couple hours. Engine was cold with freshly charged battery and started right up. Makes daily flights not longer then one tank of gas and is going to rule out $100 burger runs until I get it figured out.
 
Just like landings, never goes just perfect when you got a crowd watching.

I had the same issue this morning with cranking the battery dead but I was doing a hot start down in Mattoon IL 100 nm from home. I have the Bendix FI as well. Never had a problem with hot starts until the last few months. Now I can't get it started at all when hot. Today the FBO charged my battery as I waited for a couple hours. Engine was cold with freshly charged battery and started right up. Makes daily flights not longer then one tank of gas and is going to rule out $100 burger runs until I get it figured out.

Good luck Philip! I hope you figure it out soon.
 
Glad you finally made it out ok. Be glad that you didn't leave on Thursday. Our 9am departure became noon. They line for the 36 departure was about where we parked. Many aircraft had heat and electrical problems pop up during the prolong taxi. We finally got home around 4pm yesterday.
 
Glad you finally made it out ok. Be glad that you didn't leave on Thursday. Our 9am departure became noon. They line for the 36 departure was about where we parked. Many aircraft had heat and electrical problems pop up during the prolong taxi. We finally got home around 4pm yesterday.

That was a nightmare. Once the field reopened, I spent 2:20 in the departure taxi line for 27. 36/18 were closed for about 3 hours. There was no way to know it would be that bad when I departed from HBC. EAA/FAA/NTSB/local authorities/whoever didn't do a very good job managing the departure situation. They would launch a few aircraft, then one of the Tri-motors would come or go, then a warbird would arrive, then they would launch another handful of aircraft. It took forever.
 
As bad as it seemed at the time the controllers were faced with a really bad situation. I'm glad I wasn't inbound yesterday morning.

Condolences to the family of the lost aviator.
 
July 31 KOSH arrival holding

I noticed from liveatc.net on the Fisk arrival frequency that everyone was holding around Green Lake. Then I heard on the KOSH tower frequency taht only IFR arrivals were allowed to land, and all VFR were to hold. Then I noticed the weather at KOSH was VMC. So I initiated a thread (in the Temporary Folder) asking what was going on. This was around 10:45 CDT and we found out pretty soon that a Breezy had crashed on the SE side of 36R. We even had one pilot post to our thread that he was sitting in a T-28 trying to depart and had decided to shut down to save fuel. :eek:

Some had already been holding around Green Lake almost two hours and then they were told it would be at least another 60 minutes before they would release them. Many were diverting to Fond Du Lac and other airports.

The controllers at FISK were very courteous and professional in dealing with the impatient pilots in the holding pattern. I couldn't listen to all of it, but it was quite interesting.

After the airport opened up, I decided to delete the thread.

My sympathy and concern go out for the families of the deceased and the injured in this accident.
 
Glad you finally made it out ok. Be glad that you didn't leave on Thursday. Our 9am departure became noon. They line for the 36 departure was about where we parked. Many aircraft had heat and electrical problems pop up during the prolong taxi. We finally got home around 4pm yesterday.

Thanks Bob! Yes, that sounds like a bad deal!
 
hot starts issue request

Just like landings, never goes just perfect when you got a crowd watching.

I had the same issue this morning with cranking the battery dead but I was doing a hot start down in Mattoon IL 100 nm from home. I have the Bendix FI as well. Never had a problem with hot starts until the last few months. Now I can't get it started at all when hot. Today the FBO charged my battery as I waited for a couple hours. Engine was cold with freshly charged battery and started right up. Makes daily flights not longer then one tank of gas and is going to rule out $100 burger runs until I get it figured out.

I have the same issue. I'd really appreciate if you can let me know what it is when you figure it out.
N262DF has been doing the exact thing.
I too ran the battery dead.
Fires great cold.
A really fine mechanic suggested I have the R mag sent to a shop (can't remember the name now) for a check/repair. He said many of the slick mags come from the vendor with timing set "within limits", but NOT optimal. He said, (please don't e-beat me for this as it's from memory)- 15-25 BTDC, but the optimal is actually 19 BTDC.
I have installed a Slick start with absolutely no benefit.
I'm so aggravated, that I'm thinking of a complete swap to electric ignition system during annual.

Happy landings,
Daddyman Clinthorne
N262DF- RV 4
Dues paid
 
I had the same issue in an RV-10 with an engine from Van's. It had no impulse coupled mag. I added a Slick Start and that solved the problem. The owner never did hot starts (for a year) until I took it to Oshkosh.
 
batteries at Osh

We also found ourselves with a dead battery at Oshkosh this year. It appears we left the TCW backup battery switched on and drained the main Odyssey PC680 through the always-on backup battery charge path over several days. We were trying to depart before the airshow Wednesday, but missed the window before the airport closed.

A quick call to emergency aircraft repair and they sent a Gator out to us in the North 40. We pulled the rear mounted battery (glad I put that access panel into the rear baggage area) in a few minutes and brought it over to the repair shack to try and get it charged for an evening departure. The battery didn't appear to be charging well, so rather than risking battery issues on our flights to Pennsylvania and then back to California over the next two days I ran over and bought a new one (fully charged) from Wicks with minutes to spare before they closed. Got a ride back over the N40, re-installed the new battery and we were able to depart as soon as the airport re-opened. Great help from the emergency aircraft repair folks to get us out of there with minimal delay.

-Greg
 
We also found ourselves with a dead battery at Oshkosh this year. It appears we left the TCW backup battery switched on and drained the main Odyssey PC680 through the always-on backup battery charge path over several days. We were trying to depart before the airshow Wednesday, but missed the window before the airport closed.

A quick call to emergency aircraft repair and they sent a Gator out to us in the North 40. We pulled the rear mounted battery (glad I put that access panel into the rear baggage area) in a few minutes and brought it over to the repair shack to try and get it charged for an evening departure. The battery didn't appear to be charging well, so rather than risking battery issues on our flights to Pennsylvania and then back to California over the next two days I ran over and bought a new one (fully charged) from Wicks with minutes to spare before they closed. Got a ride back over the N40, re-installed the new battery and we were able to depart as soon as the airport re-opened. Great help from the emergency aircraft repair folks to get us out of there with minimal delay.

-Greg

Greg,
Man that sounds similar to my 'adventure'! I guess OSH is the best (and worst) place to break down.

Brent
 
Hot start problems...??

I had the same issue this morning with cranking the battery dead doing a hot start in Mattoon IL. I have the Bendix FI as well. Never had a problem with hot starts until the last few months. Now I can't get it started at all when hot. Engine was cold with freshly charged battery and started right up. Makes daily flights not longer then one tank of gas and is going to rule out $100 burger runs until I get it figured out.

I have been feeling your pain for the past few days, and am eager to see you find a solution. In my limited understanding, hot starting difficulties are related to fuel vaporizing in the fuel lines when there is heat from the engine and no fuel flow in the lines. This would cause a lean condition when trying to start a heat-soaked engine/fuel system. The function of a purge valve is to allow an electric fuel pump to push cool fuel through the fuel lines (before the engine is started) and cool them, while carrying the vaporized fuel away to the fuel tank. Of course, the fuel pump must be cool enough that it isn't vaporizing the fuel that it contains. Not sure that modifying the ignition system will have any significant effect on this problem...?? Perhaps someone out there has a hot start procedure that works well with the Bendix FI system...?? Best of luck with a solution. Let us know what solution you find.
- Roger
 
I have an RV6 with Bendix FI, magneto on the left and Lightspeed on the right. For hot starts I pull the mixture to idle cutoff and throttle wide open. Upon cranking the engine will catch and I push the mixture in and the throttle to idle.

I put a starter push button between the throttle and prop so that I wouldn't have to reach across the panel to the ignition switch.
 
Perhaps someone out there has a hot start procedure that works well with the Bendix FI system...??

Just try this...

Set 1000-1050 RPM before shutdown, then without moving the throttle, pull the mixture.

Set-up for start: Master on. Left mag on. Throttle in the 1000 RPM position, mixture at idle cut off....which is where you left both at shutdown.

Start cranking without touching anything. After 4 or 5 blades, begin pushing the mixture knob forward, slowly, while you crank. Somewhere between ICO and full rich it will fire. Release the starter switch when appropriate. Just keep pushing the mixture forward at the same slow rate until you reach full rich.

With AFP, run the boost pump with the purge valve open, then pump off, close the purge valve (run position), and initiate the cranking procedure as above. Doing so puts cool fuel in the system, which is nice.

There is no need for a rapid lever dance like the WOT method, and you get a nice soft start, unlike the guy who goes from starter speed to 1800. In terms of internal engine physics, both methods do the same thing.
 
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Just try this...

Set 1000-1050 RPM before shutdown, then without moving the throttle, pull the mixture.

Set-up for start: Master on. Left mag on. Throttle in the 1000 RPM position, mixture at idle cut off....which is where you left both at shutdown.

Start cranking without touching anything. After 4 or 5 blades, begin pushing the mixture knob forward, slowly, while you crank. Somewhere between ICO and full rich it will fire. Release the starter switch when appropriate. Just keep pushing the mixture forward at the same slow rate until you reach full rich.

With AFP, run the boost pump with the purge valve open, then pump off, close the purge valve (run position), and initiate the cranking procedure as above. Doing so puts cool fuel in the system, which is nice.

There is no need for a rapid lever dance like the WOT method, and you get a nice soft start, unlike the guy who goes from starter speed to 1800. In terms of internal engine physics, both methods do the same thing.

Dan,
I'll give that a try. I've been using the old school hot start procedure, but I don't like the "rapid lever dance" either. On my bird it takes a lot of blades.

Brent
 
Dan,

Thanks for the suggestion. I will try this next time. Seems like a straight forward way to accomplish the same goal without the gymnastics.
 
Start cranking without touching anything. After 4 or 5 blades, begin pushing the mixture knob forward, slowly, while you crank. Somewhere between ICO and full rich it will fire.

My issues always are what if the method (what ever it is) does not work after a few tries. Do you start over or go to another method?

So I'll ask the question: What do you do if you have mixture all the way in and it still has not fired? What do you do if it fired but you did not get it to stay running?
 
My issues always are what if the method (what ever it is) does not work after a few tries. Do you start over or go to another method?
So I'll ask the question: What do you do if you have mixture all the way in and it still has not fired? What do you do if it fired but you did not get it to stay running?

Stop, take a deep breath, and think about Goldilocks and The Three Bears.

Remember porridge too hot, porridge too cold, porridge just right? The situation is similar when starting an engine with a constant flow fuel injection system. The fuel-air charge presented to each spark plug can be thought of as too rich, too lean, or just right. When it's just right, the engine will start and run easily; mixtures near stoichiometric are easy to light.

All successful starting methods are fundamentally the same. We set up a mixture sweep, forcing the ratio from rich to lean, or from lean to rich. Either way, it will pass through stoichiometric at some point in the sweep.

Consider the classic lever dance. It's really a sweep moving toward lean from a condition of way too rich. First we flood it (full rich, boost pump on), which ensures we're beginning the sweep on the too-rich end. Then we put the mixture at ICO and the throttle wide open; when we start cranking, no more fuel is added, but we're supplying plenty of air. With each intake stroke the fuel/air ratio presented to the spark plug becomes progressively leaner and leaner. When the ratio passes through the stoich range (or close to it), spark makes fire. We close the throttle and open the fuel (the lever dance), hoping to remain in the sweet spot.

The method is fairly reliable because the flooding process refilled the divider and nozzle lines, which were probably boiled dry after the shutdown. Now when you "catch" the start by moving the mixture to rich, there is actually fuel immediately available at the nozzles. The downside is that it's easy to be ham-handed. Set aside the runaway RPM thing. With the throttle full open, there is a wide range of fuel flow between ICO and full rich. The open throttle makes the mixture knob a gross control.

Consider the "throttle cracked, slowly push mixture toward rich" method. It's a sweep moving toward rich from a condition of way too lean. Leaving the throttle cracked and pulling the mixture for shutdown merely made the mixture too lean to run. So, to make it fire again we just sweep the mixture from too lean back toward rich. Allowing the engine to spin 4~6 blades with the the mixture knob at ICO ensures you really are starting the sweep in the too-lean range; all air, no fuel. Now start forward slowly on the mixture knob. Since the throttle isn't wide open, mixture knob movement is a finely graduated flow control. With each rev the mixture at the cylinders is getting richer. When each cylinder returns to something near stoich, it will light. Resist the temptation to do anything quickly. Don't shove the red knob; maintain the same nice slow push.

If it doesn't light, you managed to pass through stoich. It's not a problem if you stop and think a moment; you're now at the too-rich end of the scale. You just need to sweep from rich, back toward lean. You want all air, no fuel; do the conventional lever dance if you're comfortable with it.

Or you can do a variation: go to WOT, mixture to ICO, crank, let it hit, but do nothing with the levers. It will run, more or less, and quit. You just moved everything from the too-rich end of the scale to the too-lean end of the scale by using up all the random fuel in the intake tubes and cylinders. Now you can sweep lean to rich again; set throttle cracked, spin it a bit, and start forward slowly with the mixture.
 
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On Saturday I tried a hot start with the throttle left at 1100 rpm setting and mixture at ICO. After cranking several seconds the engine would not fire. I then opened the throttle a bit more and got some action after cranking a few more seconds. I did not open the mixture until the engine started firing.

During a normal hot start with WOT and ICO the engine will start firing after less than a second of cranking and in the next few seconds the throttle and mixture are jockeyed to continue running.

I like the idea of keeping the throttle constant and advancing the mixture. Next time I will open the throttle a bit more but less than WOT.
 
On Saturday I tried a hot start with the throttle left at 1100 rpm setting and mixture at ICO. After cranking several seconds the engine would not fire. I then opened the throttle a bit more and got some action after cranking a few more seconds. I did not open the mixture until the engine started firing.

No surprise.

Nancy, can you identify where you began...too rich or too lean?
 
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Hi Dan,

I suspect I am starting from a too rich condition since I get the most rapid engine firing when the throttle is wide open.

I will try it again either this week or next weekend with an increased throttle but less than wide open.

Nancy
 
Hot Starts

Dan's method works well for hot starts. Supposed to work for cold starts, as well; unverified at this point.
 
Hi Dan,
I suspect I am starting from a too rich condition since I get the most rapid engine firing when the throttle is wide open.

Ok, if you're too rich you want to sweep toward lean; WOT and ICO, plenty of air, no fuel. Closed or part throttle and ICO would eventually do the same, but it would really drag out the process.

Are you sure you're beginning at the too-rich end of the scale? Did you prime with boost and mixture knob rich? That's how you guarantee you're beginning too rich.

You can be quite rich after a hot shutdown due to fuel boiling. The fuel temperature in the lines between the servo and the nozzles rises to something over 140F, the fuel boils, and the vapor volume increase pushes the remaining liquid fuel out of the nozzles into the intake tracts. However, if the engine sits there long enough, much of it evaporates. You don't really know what you have.

This is the condition that leads to the classic hot start procedure; flood it to make sure it's really rich, then go WOT and ICO to crank.
 
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Hi Dan,

I assume too rich because ICO and WOT always gets the engine firing. The trick is to jockey the knobs back to a more normal position since the engine will fire for only a few seconds and about half the time fails to keep running.

I never prime the engine when it's hot. Most of my hot starts are after refueling; thus restart about 10-15 minutes after shutdown. Makes sense that the fuel would vaporize, expand and fill the intake manifold, and all that's needed for start is more air.

I would like to find the throttle setting short of WOT that supports combustion as the mixture is moved towards rich.

Nancy
 
I assume too rich because ICO and WOT always gets the engine firing. The trick is to jockey the knobs back to a more normal position since the engine will fire for only a few seconds and about half the time fails to keep running.

Yep, that's a classic issue. Think about the fuel boiling problem. It spits and sputters, runs a bit, and dies because the engine pump, fuel line, servo, line up to the divider, and the individual nozzle lines are often full of big vapor bubbles. When you try to start, it hits a few licks, you go full rich on the mixture knob, and instead of a steady fuel stream at each nozzle, you get erratic (or no) liquid delivery.

The classic cure is a bit of prime flow to flush out some of the bubbles. If it was already rich (say 5 to 15 minutes after shutdown, lots of fuel boiled into the intakes) prime will just make it richer, which is fine. You're beginning from the too-rich end of the range, so use WOT and ICO, crank, and do the knob dance when it hits.

Downside to priming is fuel running out the sniffle valve.

I would like to find the throttle setting short of WOT that supports combustion as the mixture is moved towards rich.

ALL throttle settings support combustion, when mixture at the cylinders passes through the stoicheimetric range.

Let's go back to your original post:

I tried a hot start with the throttle left at 1100 rpm setting and mixture at ICO. After cranking several seconds the engine would not fire. I then opened the throttle a bit more and got some action after cranking a few more seconds. I did not open the mixture until the engine started firing.

That's not the classic WOT and ICO method (rich moving toward lean), although it is close. Nor is it the throttle cracked, slow mixture push, soft start method (lean moving toward rich).

Let's go for the latter again:

I tried a hot start with the throttle left at 1100 rpm setting and mixture at ICO. After cranking several seconds the engine would not fire.

So far correct. Assuming it has been parked a while (like for a fuel stop) you want to see 3 to 6 blades go by with the mixture in ICO. It won't fire yet. You're just clearing a bit of the boiled fuel and making sure the mixture at the cylinders is lean.

I then opened the throttle a bit more and got some action after cranking a few more seconds. I did not open the mixture until the engine started firing.

Wrong knob...leave the throttle alone, sitting at the 1000-1100 RPM position. Instead start pushing the mixture in, sloooowly, while you continue to crank. As it begins to hit, continue the slow mixture push, and keep cranking as required.

Practice exercises: For the first try, shut down hot by setting 1000 RPM and pulling the mixture to ICO. Now immediately re-start. Just begin cranking, then slowly push the mixture in.

Again pull the mixture to ICO. Wait 10 minutes. It will probably boil some fuel into the intakes. To clear it, begin cranking, let 3-6 blades go by before beginning the mixture push.
 
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Hot starts

Thanks Dan
I tried your hot start procedure on my IO-375 after a coffee stop yesterday and it worked great; even better than my previous full lean start procedure.

This is my first injected engine. When it was new used the traditional flood start, and grew so frustrated I considered reverting to a carb. Bart at Aerosport advised to hot start the engine with throttle cracked, ICO, and then advance mixture when the engine fires. This method works well, but takes fast work on the controls to keep it running, and starts at a high rpm

I found your method is results in perfect rpm after start, and does not require dancing on the engine controls after it fires.

Much obliged!

Jay
7-A
C-FXPT
 
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