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C-120 starter hard to engage

Posted: Wed May 22, 2024 7:33 am
by vindio
Hello all!

New (to me) 1947 C-120 with a C-90 engine. We're loving the airplane, but have noticed that the starter (T-handle) has become increasingly difficult to engage. Picture attached showing the switch actuator mechanism under the cowling (not familiar with the exact make/model starter).

Question: as a non-A&P, are there any adjustments that we can legally make? (shortening the actuator wire, or maybe extending the screw length that makes contact with the push-rod switch on the starter housing)? Or is this something we should take it to an AMT for?

It definitely feels like it's taking more and more and more effort/travel to engage the starter, to the point where I'm afraid we're going to yank the T-handle out of the panel, with the force required to engage the starter.

Thanks in advance!

Re: C-120 starter hard to engage

Posted: Wed May 22, 2024 7:55 am
by 6898
I cant see the starter arm, when we had that starter are's had a extended arm added think it was a continental part? But bottom line the new starter with no arms or engaged weird gear is the way to go.

Re: C-120 starter hard to engage

Posted: Wed May 22, 2024 8:16 am
by tonycondon
mine does not have that spring. that would make it harder to pull. don't mess with the geometry of the switch. it doesn't effect how hard the pull handle is to operate anyway and it will mess up the timing of the motor turning on when engaging the gear

Re: C-120 starter hard to engage

Posted: Wed May 22, 2024 8:53 am
by 8413
Best to take it to a mechanic. Each part of the system must be adjusted correctly. Here is a link that shows the process for adjustment.
https://niagaraairparts.com/wp-content/ ... 0_2003.pdf
Josh

Re: C-120 starter hard to engage

Posted: Wed May 22, 2024 9:00 am
by 6597
Does your arm have the extension? This would give you a little more leverage. Also, when i had a pull starter I had to make sure the routing of the cable thru the firewall didn't have any kinks or weird bends that would bind up the wire inside the shroud. I got a new cable/shroud that appeared teflon lined from McFarlanes that made it much easier to use. You can also try lubricating your cable shroud with TriFlow or some such oil.

viewtopic.php?f=10&t=113

Here's a pic of the starter arm extension, I have my old one somewhere....
starterarmextension.jpg
starterarmextension.jpg (331.78 KiB) Viewed 711 times

Re: C-120 starter hard to engage

Posted: Wed May 22, 2024 9:09 pm
by 6643
Go to the main web site and select Resources -> Service Letters. Service letter SLN-13 covers starter gear adjustment.

Re: C-120 starter hard to engage

Posted: Thu May 23, 2024 5:54 pm
by 6863
I don't recognize the extension or the spring as something I'm familiar with. My not recognizing them of course does not make them non-standard. Also, In the photo the spring appears to be chafing on the engine mount. I'm hoping that's just a photographic illusion, and knowing who submitted the photo I'm assuming it is just that - an illusion.

Re: C-120 starter hard to engage

Posted: Thu May 23, 2024 6:40 pm
by 6597
I don't recognize the extension or the spring as something I'm familiar with. My not recognizing them of course does not make them non-standard. Also, In the photo the spring appears to be chafing on the engine mount. I'm hoping that's just a photographic illusion, and knowing who submitted the photo I'm assuming it is just that - an illusion.
John, you are correct, it (was) not rubbing on the engine mount and it was somewhat an improvement on the 'return' tension of the pull starter cable that came with the plane when I got it. I have seen pull starters with and without a spring. Since then I'm switched to a Skytec starter so no more mussing with the pull starter. Nevertheless, I got good at troubleshooting pull starters here locally. The biggest problem I saw was cable shrouds routed every which way and the old unlined shrouds just had a lot of friction in them for the cable.

Re: C-120 starter hard to engage

Posted: Thu May 23, 2024 7:20 pm
by 6863
Thanks David. I was pretty sure that starter arrangement was in good hands if those hands were yours. The Skytek starter is undoubtedly serving you well. The owner of B&C is my very next door hangar neighbor. If (when?) I ever need to make the switch I'll probably look to my hangar neighbor for the solution. Till then, this day and age being what it is, I take some pride in yelling "clear prop" and then pulling a starter handle. That said, I admit to not being purist enough to eliminate the stater altogether.

Re: C-120 starter hard to engage

Posted: Fri May 24, 2024 8:44 am
by 8413
John...I am in the process of installing the B&C starter and can say their technical support is outstanding. But you probably already know that being neighbors :D
Josh