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Slow Starter


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I have a 65 E model that rotates very slowly when starting. The starter P/N 1109695 was overhauled 40 hours ago. The gill battery is also recently replaced. Today it started after about three revolutions, taxied to the fuel farm and got fuel. Trying to restart after getting fuel the battery acted like it was dead. I had about 12 revolutions before it wouldn't turn any more. I removed the battery and checked the specific gravity level and the battery was 75 percent charge. My bus voltage in flight is 14.2 volts. I'm planning on replacing the starter solenoid with a Lamar solenoid P/N x61-0030.

  What is the general consensus regarding my issues and is the solenoid I list the correct part. The aircraft has 4200 hours and the solenoid is original.

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spark, fuel, air...

E's should start almost instantly. Mags, SoS and fuel injectors are often culprits. Also grounds on older AC, yours is getting up there.

PM says 001466, which is a Sky-Tec number.

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Talking about slow starters....

1) Battery: new... fully charged.

2) Starter: OH'd...

3) the only thing left is what comes between all of this...

- Solenoid switch.  Known to get dirty with age....

- Wires.  Not usually known for coming apart...

- Grounds. Usually known for getting dirty or oxidized...

4) Anything that has been replaced should be reviewed for proper installation, tightness of connections, resistance to ground....

5) +1 Skytech troubleshooting guide.

PP ideas and thought process.  Not a qualified mechanic.

Best regards,

-a-

Edited by carusoam
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2 hours ago, Yetti said:

All connections should be shiny bright.   There are about 6 between the battery and the starter.

Well said, plus the ground connection between the engine and airframe like Clarence mentioned.

If all of those are good then the only connections left are the ones inside the master and starter solenoids.

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I recently went through the bad starter drill on an O-320 powered aicraft.

The starter would turn the prop, but very slowly.  I did all the standard troubleshooting; finally determined it was the starter.  I tried to have the starter re-built, but gave up on this since parts and labor apprached the cost of a brand new light weight starter.  :o

After sacrificing an appropriate number of dollars to the aviation gods, and installing the new starter, the prop spins appropriately.  According to the starter rebuild guy, it was probably a broken wire in one section of the armature.

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All good information, thanks for the feed back. I removed the power relay mounted on the battery box. The power cables needed cleaning as did the mounting hardware. I'm replacing the power and starter relays. All other connections looked good. If this doesn't fix it I will go with the Concord battery. I'll let you know the outcome in a couple of days.

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It looks like you have this all under control but ill add in a word about bus voltage and cranking since there is often a misconception about the general relation of voltage and a batteries ability to discharge. by having 14.5 in flight that simply means your alternator/voltage regulator is working properly and does not tell us all that much about your battery health. If you alternator can drive enough current to power your plane you could remove the battery in flight and you would still see 14.5V on the meter. 

Batteries have 2 important numbers, their operating voltage which is the voltage that it will read across the terminals when fully changed, and its cold cranking amperage output. The cold cranking amperage output is the amount of current the battery can drive when its 32F out for 30 seconds. This is directly related to the power the battery outputs as P=IV in this case. So a 12V battery that can deliver 100 CCA can theoretically output 1200 Watts of power (generally for a short period of time). However over time a battery ability to drive current diminishes due to the way batteries work internally but the battery is still more than capable of charging up to 12V (holding a 12V potential difference across its internal plates). Slow starting is often a sign of an old, dying battery. You can have the CCA ability of a battery tested if need be. 

As mentioned clean contacts will help as they will reduce the internal resistance of each contact joint and dissipate less current (since wires and connections on some level have an internal resistance).

While its most likely not an issue you should check the wires that connect the battery to the solenoid as they should be of sufficient gauge to operate properly. 

It could also be a short or bad connection in the starter. Most of them contain wire coils that use resin coated wire, over time this resin can degrade and short the coil out which will cause the fields inside the starter to be weaker or misaligned.  

Regards 

Dave

Edited by Dave Colangelo
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As it turns out the problem was a bad battery. It's only a year and a half old, not impressed with Gill's battery. I installed a new battery and all is good. A lot of extra work but after 50 years of service new solenoids, clean connections and a new battery cable, I should be good to go.

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2 hours ago, deanders said:

As it turns out the problem was a bad battery. It's only a year and a half old, not impressed with Gill's battery. I installed a new battery and all is good. A lot of extra work but after 50 years of service new solenoids, clean connections and a new battery cable, I should be good to go.

Hopefully you went with a Concorde battery.

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Another instance of checking the battery label for its proper spelling... C...  :)

check the spelling on your spark plug's label while you are in there... 

Funny stuff I have learned from being here a while.

Best regards,

-a-

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