Go Back  RCU Forums > RC Airplanes > RC Jets
Reload this Page >

Flameout Issues!

Notices
RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

Flameout Issues!

Old 09-12-2021, 05:18 PM
  #1  
Steve Collins
Thread Starter
My Feedback: (8)
 
Join Date: Dec 2001
Location: St.Charles, MO
Posts: 2,778
Likes: 0
Received 5 Likes on 5 Posts
Default Flameout Issues!

I have a low time Behotec 180 that flamed out twice in flight at the Route 66 jet rally this past weekend and I am at a loss to explain why it happened. Both times the flameouts occurred right at 4 minutes into the flight at the same steady throttle setting with no noticeable thing amiss during the flight up to that point. Can the timing of when the flameouts occurred just be coincidence?

The first thing one suspects and the first we eliminated is the fuel system. No sign of air bubbles in the fuel line, the filter or anywhere else except the UAT and that volume of air was pretty small; about what you would expect from a normal flight. We pulled the tank and checked the clunk and that was in good shape as well.

There is one thing different from the previous flights where the engine performed normally. I sent the transmitter in for service because the speaker had completely quit working. I was told by EspritRC that they replaced the main board in the transmitter, (Jeti DS-16), tested it to make sure all was good and returned it to me shortly before the rally. The engine started normally, just like always, so I didnít suspect there was any effect from the service work that might have caused the flameouts. I have yet to redo the stick setup on the ECU but that will happen before I do ground testing. Since the engine started normally and ran fine for 4 minutes I really donít suspect that redoing the ECU/stick learning process will solve the issue.

Of course, I discussed the flameouts with various other pilots at the rally. One asked what battery I was using to power the ECU. The battery is an HRB 3s 4000mah 100C battery. They said the voltage was too high and was heating up the ECU. This evening I charged the battery and it was at 12.5 volts coming off the charger. A manual for the type ECU the engine uses says power should be 12 volts maximum. The battery was freshly charged prior to the first flameout flight. That extra .5 volt doesnít seem to be enough to create issues?

Fuel doesnít seem to be an issue because the same fuel, Jet A with 5% Kingtech oil, was used in another smaller engine for many flights at the rally with no issues.

Anyone have similar experience with this engine?

Unknown or unknowable causes are the worst!!
Old 09-12-2021, 08:56 PM
  #2  
ravill
My Feedback: (11)
 
ravill's Avatar
 
Join Date: Jan 2003
Location: Granite Bay, Ca
Posts: 5,671
Received 75 Likes on 62 Posts
Default

See if you can reproduce the problem on the ground.


Do a “flight on the ground” and see if it is reproducible.
Old 09-12-2021, 09:14 PM
  #3  
Zeeb
My Feedback: (41)
 
Zeeb's Avatar
 
Join Date: Nov 2004
Location: St George, Utah UT
Posts: 5,347
Received 24 Likes on 22 Posts
Default

You should NOT "assume" things.....

I have one Behotec engine and have not used it much, but the start sequence is different than other Turbines I have. I will note that the KingTech engines require a three cell LiFe battery for the ECU, while maintaining that a "start" sequence must not be initiated with an ECU voltage over 10.0 volts and they are NOT lying.

This prohibition is not due to some issue with the ECU, or the engine electronics, but the starter glow plug will NOT take over 10.0 volts without burning out.

Please be aware that Turbine engine settings, unlike their glow counter parts, ARE NOT APPROXIMATE!

Start over with a fresh setup on a different model memory with the required settings and see how things go......


Last edited by Zeeb; 09-12-2021 at 09:19 PM.
Old 09-13-2021, 02:17 AM
  #4  
Blancr
 
Join Date: Apr 2008
Location: Chipping Norton, , UNITED KINGDOM
Posts: 198
Likes: 0
Received 11 Likes on 7 Posts
Default

Hi Steve,
Had a 'ramp up' board fail in my Behotec (didn't know that something like that could exist!). Symptoms were as you describe - everything normal right up to the point of failure in flight with no white smoke. May not be that but worth a check - had to send it in though for it to be discovered.
Bob
Old 09-13-2021, 03:21 AM
  #5  
rc4flying
My Feedback: (21)
 
rc4flying's Avatar
 
Join Date: Oct 2002
Location: Hermitage, PA
Posts: 656
Received 2 Likes on 2 Posts
Default

As I read the original post describing the problem, I had just experienced this very same type of issue and thought I how ironic to see this.
I did all of the very same troubleshooting to search for my problem. Long story short, My motor was a Jet Munts 200 and my issues started in a very same manner. I had never had a flame out since owning the motor over several yrs of use. Mine flamed out about 5 minutes into my flights with no visual signs. I inspected fuel system and checked all my cables after first flame out, even tried a different battery. After second flame out on my next day out to the field, It turned out that I found a loose screw mounting the motor's front circuit board. Tightened the screw and checked all wire soldered points on board. I didn't change anything else. Took plane back out to the field this past Saturday and got my flawless running motor back again. 3 great flights.
I know this may sound strange to some, but this is my personal experience over the past couple weeks. May be worth looking at and good luck with your troubleshooting.
Old 09-13-2021, 05:04 AM
  #6  
Steve Collins
Thread Starter
My Feedback: (8)
 
Join Date: Dec 2001
Location: St.Charles, MO
Posts: 2,778
Likes: 0
Received 5 Likes on 5 Posts
Default

I absolutely will be doing ground testing to try and reproduce the flameout and make adjustments before it flies again.
Old 09-13-2021, 06:12 AM
  #7  
CARS II
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 6,182
Received 74 Likes on 63 Posts
Default

I had a similar experience with my Boomerang XL, the engine stopped after 4-5 min after TO, I have it on video, end up been clear algae plugging the fuel filter, clean it and the symptoms went away.
Old 09-13-2021, 06:49 AM
  #8  
jvaliensi
My Feedback: (1)
 
Join Date: Apr 2006
Location: northridge, CA
Posts: 347
Received 36 Likes on 28 Posts
Default

I just read a similar post about a Behotec on FB. Turns out the electronic board was faulty and Behotec fixed under warranty.
Jeti Duplex Owner's Group (Sept 10th)

Last edited by jvaliensi; 09-13-2021 at 06:51 AM.
Old 09-13-2021, 09:23 AM
  #9  
Zeeb
My Feedback: (41)
 
Zeeb's Avatar
 
Join Date: Nov 2004
Location: St George, Utah UT
Posts: 5,347
Received 24 Likes on 22 Posts
Default

You could try calling Woody at Ultimate Jets, they are the USA Behotec folks;

https://www.ultimate-jets.net/
Old 09-13-2021, 01:38 PM
  #10  
sysiek
My Feedback: (176)
 
sysiek's Avatar
 
Join Date: Feb 2009
Location: Chicago , IL
Posts: 2,145
Likes: 0
Received 31 Likes on 27 Posts
Default

Maybe the vent has limited air flow, ones I have bad valve with similar problems the electromagnet was weak and the fuel has been restored until closing the fuel flow

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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.