VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

  #31  
Old 01-26-2021, 12:54 PM
rvbuilder2002's Avatar
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 9,253
Default

Quote:
Originally Posted by Piper J3 View Post
Correct. Idle warm-up at higher speed is beneficial. I bring idle speed to ~ 2800 RPM as soon as engine starts.
Fast idle during cold warm up is a good idea but I wouldn't recommend RV-12 owners go above the 2500 RPM limitation when the oil temp is below 120 F.

This is to assure that since the oil pump has to suck oil out of the remote tank, that overly viscous (cold) oil doesn't ever cause a cavitation of the oil pump and the resultant bad things that could go with that.
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.

Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
Reply With Quote
  #32  
Old 01-26-2021, 03:42 PM
trecool44 trecool44 is offline
 
Join Date: Oct 2020
Location: Weirsdale
Posts: 16
Default

I have performed the test with the choke on as suggested. I am getting the same drop and roughness so I believe I have an ignition issue. What are the tests I can do on the coils themselves? The issue seems to be getting worse, I had to run for a few minutes at 4500 to get it to smooth out. Thanks again.
__________________
2010 - RV12 and Loving it
Central Florida
Reply With Quote
  #33  
Old 01-26-2021, 04:33 PM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 2,306
Default

Quote:
Originally Posted by trecool44 View Post
I have performed the test with the choke on as suggested. I am getting the same drop and roughness so I believe I have an ignition issue. What are the tests I can do on the coils themselves? The issue seems to be getting worse, I had to run for a few minutes at 4500 to get it to smooth out. Thanks again.
You very likely have carb and not ignition problem.

Follow post #30 and report back...
__________________
-
Jim Stricker
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
Bought Flying RV-12 #120058 Oct 2015 with 48TT - Hobbs now 642

LSRM-A Certificate 2016 for RV-12 N633CM
Special Thanks... EJ Trucks - USN Crew Chief A-4 Skyhawk
MJ Stricker (Father & CFI) - USAAF 1st Lt. Captain B-17H
Reply With Quote
  #34  
Old 01-26-2021, 05:10 PM
trecool44 trecool44 is offline
 
Join Date: Oct 2020
Location: Weirsdale
Posts: 16
Default

Carbs have been balanced and rechecked. Floats have been replaced and weighed before install. I’m still thinking coils or trigger coils.
__________________
2010 - RV12 and Loving it
Central Florida
Reply With Quote
  #35  
Old 01-27-2021, 09:45 AM
rvbuilder2002's Avatar
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 9,253
Default

Quote:
Originally Posted by trecool44 View Post
Carbs have been balanced and rechecked. Floats have been replaced and weighed before install. Iím still thinking coils or trigger coils.
I have never seen you mention anything about checking the fuel.

Have you tried different fuel? Do you know for sure it is fresh?

I have seen poor fuel cause strange issues, particularly in cold operating conditions.
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.

Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
Reply With Quote
  #36  
Old 01-27-2021, 09:57 AM
trecool44 trecool44 is offline
 
Join Date: Oct 2020
Location: Weirsdale
Posts: 16
Default

We have non ethanol 93 delivered from a local oil company. I have not tried other fuel as the non-ethanol 93 is scarce around here. Hey deliver to 4 other customers in our community with no issues. I can’t completely discount fuel quality at this point. I really appreciate all the input from everyone here.
__________________
2010 - RV12 and Loving it
Central Florida
Reply With Quote
  #37  
Old 01-27-2021, 10:31 AM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 2,306
Default

If youíre inclined and follow post #30 above, also record L and R EGTís. Do this during initial warmup at 2800 RPM, again after you taxi to runup pad, and also in cruise flight.

Something like thisÖ.
-
Attached Thumbnails
Click image for larger version

Name:	Screen Shot 2021-01-27 at 12.31.13 PM.png
Views:	30
Size:	61.8 KB
ID:	7547  
__________________
-
Jim Stricker
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
Bought Flying RV-12 #120058 Oct 2015 with 48TT - Hobbs now 642

LSRM-A Certificate 2016 for RV-12 N633CM
Special Thanks... EJ Trucks - USN Crew Chief A-4 Skyhawk
MJ Stricker (Father & CFI) - USAAF 1st Lt. Captain B-17H
Reply With Quote
  #38  
Old 01-27-2021, 11:37 AM
NinerBikes NinerBikes is offline
 
Join Date: Dec 2018
Location: Granada Hills
Posts: 1,102
Default

Quote:
Originally Posted by trecool44 View Post
We have non ethanol 93 delivered from a local oil company. I have not tried other fuel as the non-ethanol 93 is scarce around here. Hey deliver to 4 other customers in our community with no issues. I can’t completely discount fuel quality at this point. I really appreciate all the input from everyone here.
After doing lots of research on fuel quality and floats that end up failing, in Bing carb equipped motors, I am of the opinion that if you are turning over your fuel, going through a tankfull per month 12 to 15 gallons worth, Ethanol fuel is rarely a problem for floats. What is a problem is fuel providers that "dump" cosolvents in their gasoline as a way to get rid of a problem solvent when refining fuel, instead of paying for it's disposal. At least here, in CA, IMHO, the two worst fuel brands are Shell and Valero. Both their gas and their diesel fuel deliver about 8 to 10% less MPG's in all the fuel log fillups I"ve kept for my vehicles since about 1980. I don't know who the dumpster fire fuel makers or sellers are in Florida. Cosolvents are really "fluff" or filler in fuel, takes up volume in a gallon of gas, but really doesn't add much energy or HP to a gallon of gasoline. It's using your motor as an incinerator for a waste product, so to speak, from the refining process.

My point it, burn up what's in the plane, get a couple of 6 gallon fuel tanks and go buy some FRESH premium fuel at a busy fuel station that's not the two brands mentioned above. Don't buy fuel from the airport, for these tests.

See if your problem goes away with the fresh fuel. A lot of places say that their fuel is ethanol free... don't believe it, test it yourself, get an ethanol tester vial/ graduated cylinder and find out for yourself. https://www.amazon.com/Briggs-Stratt...773623&sr=8-12
__________________
Donated
RV-12, #212 N72DJ, bought flying. A Blessing in disguise. Thank you Double D!

Last edited by NinerBikes : 01-27-2021 at 11:54 AM.
Reply With Quote
  #39  
Old 01-27-2021, 11:55 AM
sailvi767 sailvi767 is offline
 
Join Date: Sep 2010
Location: Charlotte NC
Posts: 1,285
Default

Quote:
Originally Posted by trecool44 View Post
We have non ethanol 93 delivered from a local oil company. I have not tried other fuel as the non-ethanol 93 is scarce around here. Hey deliver to 4 other customers in our community with no issues. I canít completely discount fuel quality at this point. I really appreciate all the input from everyone here.
How old is the gas once itís in your aircraft. Auto fuel starts deteriorating after 30 days.
__________________
RV-6 sold
F-1 Rocket
Reply With Quote
  #40  
Old 01-27-2021, 11:59 AM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 2,306
Default

Yes, try fresh Mogas. Search online for Top Tier suppliers. 93E10 is a common high-octane fuel recommended for Rotax 912. Ethanol is fine, no need for ethanol-free.

Years ago I had a conversation with a petrochemical engineer and he told me how off-brand suppliers get fuel that is refined from slop tank oil. This is oil that is culled from pipelines when different liquids are transported. It is oil that is at the interface where the liquids mix in the pipeline. His advice: stick with Top Tier suppliers…
__________________
-
Jim Stricker
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
Bought Flying RV-12 #120058 Oct 2015 with 48TT - Hobbs now 642

LSRM-A Certificate 2016 for RV-12 N633CM
Special Thanks... EJ Trucks - USN Crew Chief A-4 Skyhawk
MJ Stricker (Father & CFI) - USAAF 1st Lt. Captain B-17H
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 11:11 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.