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Hard starting

dan carley

Well Known Member
I have a Rv6 with a180hp engine
It’s very hard starting the first or second crank
It has a very tough time starting
The timing is good I have a skyteck starter concord
Battery battery 2 yrs old but been doing
It all the time. Could it just be high compression

Thanks for the help
Danny carley
 
Starting

I have a Rv6 with a180hp engine
It’s very hard starting the first or second crank
It has a very tough time starting
The timing is good I have a skyteck starter concord
Battery battery 2 yrs old but been doing
It all the time. Could it just be high compression

Thanks for the help
Danny carley

Check your plug gaps. Should be .016 and not much more. Magnetos don't work well on wide gaps like car engines or with electronic ignition. Higher compression makes the problem worse.
 
My -6 was hard to start, especially hot
0320, CS and Carb
Turned out to be mag(s)
Key start grounds out the right mag normally to start on the Left Mag that has the impulse coupling
So only firing one set of plugs while cranking
(2) P-mags later and it starts like it should
Also, 2 separate toggle switches and a start button now
Mike
 
If you mean it has a hard time turning over the first blade or two, I have seen this when the battery/engine/etc didn't have a good ground or positive connection.

In my old piper warrior, when it started getting slow, I had to check the ground connection on the battery, clean it really good, reconnect it, and would turn over at full speed again.

You may have a bad crimp on the engine/firewall connection or anywhere back to the battery. I have seen a lot of...variation...shall we say in the crimps on the fat cables. One of them, a good tug pulled it right out of the lug.
 
Probably some resistance for any number of possible reasons. A multi-meter won't do it. Do the aforementioned connection quality checks.

Check voltage under load to help zero in on the component via this:

https://skytec.aero/aircraft-starter-performance-issues/

Let us know.

Edit = from the OPs description and high compression comment, I was guessing hard to turn the engine over. Sounds like others read it differently. Symptom clarity and details are needed.
 
Last edited:
Danny,
Mike touched on this above...
Mags....more to it than timing.
Age?
Last 500hr?
Is the impluse coupling working?
Plug wire? checked with tester?
Plugs checked for resistance? cleaned/gaped correctly

The Magneto ignition system is a SYSTEM and needs Mags-Wires-Plugs all in proper shape to perform correctly.
First sign something is amiss....hard starting!
 
Did you resolve the issue?
A few moons ago, there was a rash of problems with similar symptoms. It was discovered that the firewall mounted starter solenoid contact “disk” was not rotating properly. There where several examples of this on different aircraft.
You can’t test with a meter as it won’t show up as a high resistance with no load. You can jumper past the solenoid but that’s a risky endeavor with a rotating prop.
Solenoids are cheap and easily swapped out. Worth the investment if you hit a wall on this…..
 
The Skytech light weight starter has a solenoid built into the starter. On my engine this solenoid became loose and caused intermittent starter problems such as taking several engagements of the starter to actually turn the engine over. I initially thought it was (1) a low/problem battery, (2) poor ground cable, (3) a failing firewall ignition solenoid, and (4) bad positive battery cable. I replaced all of these parts over a two year period.

It wasn’t until I was doing an annual condition inspection that I discovered the solenoid on the starter actually twisted in its housing when I tightened the positive connection.

Since Skytech doesn’t sell parts or publish a repair manual for this starter I turned to this forum for suggestions and found out there is a Ford starter solenoid that easily and cheaply replaces the Skytech solenoid. Job took about two hours because I had to drop the starter and plenum to gain appropriate access to the solenoid and of course there’s always one bolt that’s hard to get access too - both for removing and even more to reinstall.

Since the repair my starter has worked marvelously!
 
If you mean it has a hard time turning over the first blade or two, I have seen this when the battery/engine/etc didn't have a good ground or positive connection.

In my old piper warrior, when it started getting slow, I had to check the ground connection on the battery, clean it really good, reconnect it, and would turn over at full speed again.

You may have a bad crimp on the engine/firewall connection or anywhere back to the battery. I have seen a lot of...variation...shall we say in the crimps on the fat cables. One of them, a good tug pulled it right out of the lug.

Lots of good advice in this post. Helped a friend with a hard starting RV-7 a decade ago and the issue was the connection between the engine and airframe ground.
 
Ground

Simple way to prove this is an automotive jumper cable from the battery ground terminal to the starter housing. See if it cranks better.
 
I had a hard starting issue on my 390 a year ago, with 350HSN mags. Despite not being at 500 Hours, I was advised to take them in to be overhauled, and it fixed the problem. Shop told me this was a common recent problem as Slick mags are are being built/overhauled with inferior cam follower blocks that wear sooner. Although timing may be right, the dwell is less resulting in a weaker spark. One way to check for this before taking the mags off is to do a high altitude, say over 8K feet, flight, lean aggressively, and do a mag check. If your mags are not in top condition, your heart may stop for a moment until you return to "both"!
 
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