My new engine is harder to start

SixPapaCharlie

SixPapaCharlie

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Former plane had the O-320. I hit the starter and it turned freely and fired up with no issue.


New plane has a O-540. I hit the starter and it starts to spin but then has moments of hesitation between the spinning portion of startup.

It definitely takes longer to start but mostly it feels like the starter is barely strong enough to turn the prop.

does this sound like a starter thing, a battery thing, or is is just a bigger engine thing?

Watch this dude's. Notice on the first spin, it stops briefly before doing the spinny part.
What is happening there. Mine does that. I prefer it t just turn over a couple times, not have that hesitation, and start up.

 
Could be a starter thing, or a battery thing. The O-540 in the club Dakota didn't do that, nor does my IO-540, which is higher compression. Do you have a means of charging the battery? You could also have your mechanic load test it. I know for the Lance there are two Concorde batteries (@NealRomeoGolf just enlightened me on this) available, one with more cranking amps. I believe the factory wet cell had even fewer amps than the Concorde. I would start by investigating the battery issue. I assume it's always done this, not a recent issue since the deep discharge?

If the battery is OK, maybe starter brushes?
 
The hesitation can be at compression positions, it can be battery (check voltage while starting), starter, starter relay, starter switch.
My starter did this and then finally died completely. The annoying thing is it was only 5 years old…and mechanic just shrugged saying that’s about right.
 
You see this a lot as "things" in the starting system start to get weak. Battery, possibly. Starter getting weak, possibly. Corrosion in the battery cable, possibly.

The easiest test would be to borrow a known new battery and see if it makes a difference.
 
How old is the battery? Your battery is behind the baggage compartment, right? That's a long run to the starter, and a lot of owners have replaced those cables with Bogert copper cables. Clean all the hot connections, solenoid connectors and grounds, especially the battery to airframe. You can take a voltmeter and see if you're losing voltage due to a dirty main solenoid contactor.

Your Comanche has a shower of sparks system that fires the number 1 cylinder continuously as it reaches top dead center. It's a great system when properly maintained...unfortunately most wrenches have no clue as to how it works, and it often get overlooked and the spark gets weak. Finally, don't be afraid of the primer. I use at least 5 shots, 6 when it's cold. If it doesn't start in three or four blades, I give it a couple more. Usually fires right off.
 
Chip Sylverne said:
How old is the battery? Your battery is behind the baggage compartment, right? That's a long run to the starter, and a lot of owners have replaced those cables with Bogert copper cables. Clean all the hot connections, solenoid connectors and grounds, especially the battery to airframe. You can take a voltmeter and see if you're losing voltage due to a dirty main solenoid contactor.

Your Comanche has a shower of sparks system that fires the number 1 cylinder continuously as it reaches top dead center. It's a great system when properly maintained...unfortunately most wrenches have no clue as to how it works, and it often get overlooked and the spark gets weak. Finally, don't be afraid of the primer. I use at least 5 shots, 6 when it's cold. If it doesn't start in three or four blades, I give it a couple more. Usually fires right off.
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I have to prime the hell out of it before the aforementioned process even starts.
 
something isn’t as correct as it could be - the one in my Comanche (O-540) fires off quickly.
 
I had the same issue with my 182. It was that way the first 5 years I owned it. I just figured that 0-470 was just too much for the battery so I ordered a new Concorde battery last fall. When the mechanic installed the battery he checked the rest of the electrical system & found a loose connection near the starter. Now she fires right up. Maybe I didn't really need that new battery...
 
Our Comanche used to be that way until it got a new lightweight starter (Skytec I think). You can nearly taxi with that darn thing now.
 
SixPapaCharlie said:
I have to prime the hell out of it before the aforementioned process even starts.
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After you prime the normal amount, try giving it a sliding shot of prime as you hit the starter. That technique changed my world.
 
I agree that there is probably an issue with a weak battery or bad connection.

In the mean time, when doing the walk around, pull the prop through the customary two revolutions, the ALMOST to top dead center, just far enough that compression does not turn it back down.
The compression leaks off as you prepare to start, and your starter has 180 degrees instead of 90 to accelerate the prop, and that greater inertia will take it through on the first try, no pause.

Our 352 cu inch, 6 cylinder Franklin had high compression, and in cold weather, that was vital to getting started. After the first winter, we installed the larger size battery and heavier cables, which solved the problem.
 
I was going to say battery, then starter after but…


SixPapaCharlie said:
I have to prime the hell out of it before the aforementioned process even starts.
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1) could you be giving her too much fuel to start?
2) are you letting that fuel vaporize in the cylinders? Prime, then wait say… 5-10 seconds?
 
How old is the battery? Voltage only tells part of the story.
 
First step is to check all cable connections from battery to starter. Check the condition of the cables as well. Check voltage of the battery just after running and after it's sat for a day or so. I went through all of this with symptoms similar to yours. Ultimately it required a new starter and now starts on 1st or 2nd blade.
 
Hang 4 said:
First step is to check all cable connections from battery to starter. Check the condition of the cables as well. Check voltage of the battery just after running and after it's sat for a day or so. I went through all of this with symptoms similar to yours. Ultimately it required a new starter and now starts on 1st or 2nd blade.
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This. Your problem is electrical. Battery, big wires, or starter. Some of the extremely lightweight starters struggle on the first blade on engines with large displacement cylinders (your 540 qualifies) and high compression (yours is 8.5:1). So it could be a starter that isn't and maybe never was up to snuff. Or it could be the battery (how old is it?), or it could be a corroded connection on one of the big wires that run between the battery, master solenoid, starter solenoid, and the starter. Your airplane is 60 years oldish, so bad connections are a distinct possibility.
 
SixPapaCharlie said:
Former plane had the O-320. I hit the starter and it turned freely and fired up with no issue.


New plane has a O-540. I hit the starter and it starts to spin but then has moments of hesitation between the spinning portion of startup.

It definitely takes longer to start but mostly it feels like the starter is barely strong enough to turn the prop.

does this sound like a starter thing, a battery thing, or is is just a bigger engine thing?

Watch this dude's. Notice on the first spin, it stops briefly before doing the spinny part.
What is happening there. Mine does that. I prefer it t just turn over a couple times, not have that hesitation, and start up.

Click to expand...
I added a battery tender to the airplane (IO-540) which makes a big difference. Even though you may have a decent battery they will have more zip coming off of a bettery tender a few moments prior to starting. Reviewed our log book and the Concorde battery was last replaced in May of 2013, we are going to replace it as I don't trust it if the airplane sits during a week long trip without the battery tender.
 
Sometimes starters get tired, sometimes batteries get tired, sometimes contactors get tired, sometimes connections get tired. The key is figuring out which it is. A good mechanic with a volt ohm meter should be able to sort it for you.
 
+1 on all the check the electrical connections recommendations. Especially checking condition and considering upgrade cables and/or Battery.
Also the Skytec Starters are awesome and would help as well.

Brian
CFIIG/ASEL
 
If I was going to try and ID a bad connection, I'd get everything opened up, crank it a bit w/the mag's off, then take a IR temp gun and check the temp of -every- connection (including the battery) going to the starter you can, as quickly as possible. A bad connection will have a higher temp. Don't forget the grounds.
 
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How many cylinders have primers? The more that have them the more you must pump the Primer. If 1 primer line breaks you will be washing the outside of the engine with fuel. Easy to visually check. Quite common. Primer fittings get coked up and do not deliver fuel.
If the magneto e-gap is incorrect there may be starting issues. I am a fan of having both mags with impulse coupling.
Often overlooked is the ground side of the starter circuit. By creative use of jumper cables you can bypass units and provide additional paths to and from the starter to aid to diagnostic.
 
Timing?

One of our ships was a pain in the butt to start, turns out it was the timing.
 
The obvious answer is to remove the piston rings. All the blow by will lower compression, and the starter will turn the engine over easily.
 
It's definitely not a fuel problem. It's not likely an ignition problem. It's a starting circuit problem, and it needs a competent mechanic, with a multimeter, to measure voltage drops while you crank. He needs to measure the drops across every connection between the battery (including the battery-to-airframe ground) and the starter, including the starter's ground circuit from the starter housing the the firewall. The Skytec troubleshooting procedure posted by Baboss in post #17 is the way to do it.

That said, I will posit that the master and starter contactors are the biggest culprits. They so often are. Most people don't have much idea what happens inside those things, since they're sealed, and if the starter cranks at all, the contactors must be ok, right? NO. Not right. Contactors have copper contacts inside that age and oxidize. They burn as they open and the inductive spike causes an arc across the contacts. Some people have spent AMUs replacing batteries and starters and cables, when the problem all along was a $40 contactor. The starter current runs through both the master and starter contactors. Any resistance in them is trouble.

Ohm's Law lesson. E = I x R. Voltage is equal to amperage times resistance. That starter draws a good 250 amps. If a contactor has a resistance of a fiftieth of an ohm, 0.02 ohms, you'd have trouble seeing it with an ohhmeter, but that contactor is causing, theoretically, a five-volt drop. Can you afford that in a 12-volt circuit? Nope. The battery itself will have a voltage drop at that current draw, due to its internal resistance, and that five-volt drop is added to it. You could end up with three volts at the starter. You ain't going flying.

The cheapest fix involves an expensive mechanic. Not the opinions of other pilots.
 
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I'm not sure what or where the problem is but what you need to fix it is:

proxy-image
 
AGAIN!………I know where there’s a very nice Grumman Tiger for sale.

We will never let you forget what you said about future plans in one of your Traveler videos. Karma, man.
 
My first guess would be new battery cables. I believe your Piper is of the vintage that would've come with aluminum battery cables, which save weight and were fine when new, but don't do too well as they age and fatigue. They probably also look like they've caught fire once or twice, and that is probably because they've caught fire once or twice.

One of the first things I did on the Aztec was replace all the battery/starter cables with copper. Threw the props over great, and started wonderfully. I would start there, although if your battery is older it might be due for replacement. Concorde is my preference on batteries.

After you do that, a SkyTec NL starter will throw the prop over very well. That's what's on newer Malibus, etc. One Navajo I flew had those, and it really does make starting easier. I never bothered to spend my own money on those, but I sure liked flying planes that had them. But don't do this until the batteries.

A good functioning ignition system also helps a great deal for starting. I always wanted to do one of the electronic ignition boxes in place of a magneto, but about the time I would've gotten to that I ended up going to the 414 and then the MU-2.

Maybe I need to get a Lancair 360 like I thought about buying back before I got the Aztec so I can finally get around to doing all of these dumb projects.
 
Bogert Aviation makes copper cables to replace aluminum, as well as cable kits for other airplanes. https://bogertaviation.com/

But aside from the fire hazard presented by aluminum, a decent troubleshooting regimen should be done anyway. It's easy enough to replace all the cables, but still have starting issues because the fault lies elsewhere. Now you're ordering other parts and waiting for them, and pulling stuff apart all over again.

I should mention that an analog multimeter is better for this work. Digital meters will just have numbers and pieces of numbers scrolling all over the place as the voltage rises and falls during the tests. A needle shows a trend that makes sense.
 
Our club's Aztec does that exact same thing, both engines. Lycoming 540. I just assumed it was a "big old engine" thing. The Cirrus 550 never did that though..
 
Tantalum said:
Our club's Aztec does that exact same thing, both engines. Lycoming 540. I just assumed it was a "big old engine" thing. The Cirrus 550 never did that though..
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Old airplanes. Old contactors, old cables, dirty ground cables, on and on it goes. If they're both doing exactly the same thing I'd suspect the master contactor first, since starter current for both engines goes through it.
 
Tantalum said:
Our club's Aztec does that exact same thing, both engines. Lycoming 540. I just assumed it was a "big old engine" thing. The Cirrus 550 never did that though..
Click to expand...

See my previous post about Aztec aluminum cables looking like they caught fire. That usually is because they caught fire.
 
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