Go Back  PPRuNe Forums > Ground & Other Ops Forums > Engineers & Technicians
Reload this Page >

Lycoming AEIO 540 RPM Fluctation

Wikiposts
Search
Engineers & Technicians In this day and age of increased CRM and safety awareness, a forum for the guys and girls who keep our a/c serviceable.

Lycoming AEIO 540 RPM Fluctation

Thread Tools
 
Search this Thread
 
Old 31st May 2017, 10:20
  #1 (permalink)  
Thread Starter
 
Join Date: Jun 2008
Location: Manchester
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Lycoming AEIO 540 RPM Fluctation

Have a 540 in my stable, thats causing me to scratch my head, Newly overhauled out of the box, new everything, runs great on the ground, above approx 2000ft its rpm fluctuates by about 100 RPM

Changed
Prop Governor
Fuel Injector

Symptoms still remain.

Very open to advice, suggestions at this stage, Thanks in advance
Fleep is offline  
Old 31st May 2017, 11:34
  #2 (permalink)  
 
Join Date: Feb 2006
Location: Station 42
Age: 69
Posts: 1,081
Received 93 Likes on 39 Posts
That's odd. What aircraft?
A few questions to build up a picture:
1) Do the the revs fluctuate all through the range?
2) What happens if you adjust the mixture?
3) Is the manifold pressure steady?
4) Is the alternate air flap sealing OK?
stevef is offline  
Old 31st May 2017, 13:14
  #3 (permalink)  
 
Join Date: Oct 2006
Location: USA
Posts: 753
Received 25 Likes on 20 Posts
Fleep

If Bendix RSA could be automatic mixture control unit at altitude or induction leak at speed. May want to put gauges on fuel servo and check outputs. But since new install may consider contacting overhaul shop for input and possible warranty to offset your additional costs.

Good luck!
W1
wrench1 is offline  
Old 1st Jun 2017, 07:37
  #4 (permalink)  
 
Join Date: Feb 2006
Location: Station 42
Age: 69
Posts: 1,081
Received 93 Likes on 39 Posts
Unlikely that there would be much effect (flashover) at 2000 feet but it's worth checking that you have a vented magneto timing window plug. There should be 3 or 4 holes in it.
stevef is offline  
Old 1st Jun 2017, 22:14
  #5 (permalink)  
Thread Starter
 
Join Date: Jun 2008
Location: Manchester
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Thanks very much for the feed back, alternate air door was not something i had thought of, how ever its shut tight, excellent suggestion though,

Only happens at cruise setting, 2300 rpm or there about and only above 2000 ft , rpm fluctuates up and down 80-100 rpm. pilot feels like its the prop changing pitch, however surly this would happen on ground run if this was the case.

Mag flash over?
these are un-pressurized mags, but will check for venting. its a possibility as this engine is being operated in 35 deg plus ambient temps,
Thanks again
Fleep
Fleep is offline  
Old 30th Jun 2017, 05:38
  #6 (permalink)  
 
Join Date: Feb 2005
Location: NZ
Age: 72
Posts: 205
Likes: 0
Received 0 Likes on 0 Posts
Fleep

Did you find what the fault was. (just curious)
Fark'n'ell is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.