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Starting issues


Carsten H.
(@carl)
Trusted Member
Joined: 3 years ago
Posts: 81
Topic starter  

Hi all. F-165 has twice started and then quit recently. If I pump the throttle it stays running. In the past the engine fired on the first or second stroke and ran w/o hesitation. No problems on run-up or airborne. I'm thinking it might be a sticking float. Gascolator is clean and I drain the float bowl every annual. Any thoughts would be appreciated.

Carl


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resto108
Reputable Member
Joined: 16 years ago
Posts: 254
 

Dumb question: Is the mixture arm actually moving to the full rich position? Pumping the throttle moves the accelerator pump, which gets its fuel from the float bowl. So if the float was stuck, where would that fuel come from? It sounds like you can't get a rich enough mixture on starting to maintain combustion, then when it warms up, it will run. Check for intake leaks too. Its either too much air or not enough fuel.


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Carsten H.
(@carl)
Trusted Member
Joined: 3 years ago
Posts: 81
Topic starter  

So here's an update to my starting issue. One of the intake valve guides had come loose (quite loose) and although the compression was unaffected it must have allowed unmetered air into the induction system. 


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lawheelock
Prominent Member
Joined: 16 years ago
Posts: 765
 

I am curious about the history of the cylinder that you had a loose intake guide?  Recent overhaul?  Standard or oversize guide>  Bronze or cast iron guide?  Franklins rarely have problems with intake valves/parts.

 

Larry Wheelock

Larry Wheelock, A&P/IAStinson 108 N584LW 180 LycTexas in Winter; Indiana in Summer


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Carsten H.
(@carl)
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Joined: 3 years ago
Posts: 81
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Hi Larry. About 13 years ago during annual inspection we discovered a very worn guide in #4. And the valve was also worn. Also had a crack from spark plug hole to valve seat. Got a replacement yellow tagged cylinder from a reputable supplier. It had a bronze guide without the shoulder installed. Engine has some 1000+ hrs SMOH. I've owned it since 1984.


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lawheelock
Prominent Member
Joined: 16 years ago
Posts: 765
 

Thanks, Carsten.  But I am still curious about the "reputable supplier" of overhauld cylinders because I have had some experiece of cylinder problems from at least two "reputable suppliers" one being Lucas and one from Li'l Red Arrow.

The guide not having a shoulder is a non issue if it was properly fitted and installed.  Some people may install guides without following the manual requiring a heated cylinder before installation because it saves time.

It was properly done if it lasted 12-13 years.  These castings are very old and who knows how many times they have been reworked.

Larry Wheelock, A&P/IAStinson 108 N584LW 180 LycTexas in Winter; Indiana in Summer


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Will Ware (Webmaster ISC)
(@stinsono)
Member Admin
Joined: 3 years ago
Posts: 335
 
Posted by: @lawheelock

Thanks, Carsten.  But I am still curious about the "reputable supplier" of overhauld cylinders because I have had some experiece of cylinder problems from at least two "reputable suppliers" one being Lucas and one from Li'l Red Arrow.

The guide not having a shoulder is a non issue if it was properly fitted and installed.  Some people may install guides without following the manual requiring a heated cylinder before installation because it saves time.

It was properly done if it lasted 12-13 years.  These castings are very old and who knows how many times they have been reworked.

I would suggest Chris at Airworx.


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Carsten H.
(@carl)
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Joined: 3 years ago
Posts: 81
Topic starter  

The supplier was a long time source and ISC member who stepped back from the business after loosing his son in Iraq/Afghanistan.

We heated the cylinder to 650°f, (I believe it was) got the size measurement and installed a guide with .0025" interference fit. All better now. 5hrs on repair.


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