Go Back  R/C Tech Forums > General Forums > Nitro Off-Road > Offroad Nitro Engine Forum
Regular flameouts during refueling >

Regular flameouts during refueling

Like Tree5Likes
  • 3 Post By Winner's Circle
  • 1 Post By hairymuffin
  • 1 Post By hairymuffin

Regular flameouts during refueling

Reply

Old 04-12-2017, 01:48 PM
  #1  
Tech Regular
Thread Starter
 
Join Date: Sep 2009
Location: Warsaw, Poland
Posts: 339
Default Regular flameouts during refueling

Hi everyone,

I'm having regular problems with flaming out during refueling with a fuelgun. I've been trying to solve this issue for so long without success that I thought it's about time to ask some engine guru's.

Observations:
The engine seems to flame out because of lack of fuel - I'm sure that it's not because of too rich bottom. So I thought - probably too lean bottom... Last race I set it pretty safe - that is: when the engine was idling on the box it would build up and bog after applying full throttle after several seconds. Still the engine died 2 times in the main final (both times during refuelling).

What I tried:
- leaner bottom end
- richer bottom end
- new glow plug
- fresh fuel
- new fuel tubes
- sealing backplate of the engine
- keeping the engine at idle while refueling
- reving the engine when refueling (I know it's not good - I did it just to try)

My setup:
- Mugen MBX7
- Alpha Lutz WE + 2107 pipe + 7mm venturi
- Rapicon fuel
- Losi fuel gun

I'll appreciate any ideas
Donat is offline  
Reply With Quote
Old 04-12-2017, 02:55 PM
  #2  
Tech Elite
iTrader: (11)
 
kgombe's Avatar
 
Join Date: Aug 2008
Posts: 3,201
Trader Rating: 11 (100%+)
Default

seen this happen with a local racer numerous times no matter what car or engine... but he now uses a fuel bottle and that went away...

it's usually a fat bottom, or you just coming in to late for fuel?
kgombe is offline  
Reply With Quote
Old 04-12-2017, 03:04 PM
  #3  
Tech Master
iTrader: (2)
 
Winner's Circle's Avatar
 
Join Date: May 2005
Location: Atlanta, Georgia USA
Posts: 1,169
Trader Rating: 2 (100%+)
Default

I think it is a fat bottom. Try a hot plug and see if that helps.

Lee
Winner's Circle is offline  
Reply With Quote
Old 04-12-2017, 03:07 PM
  #4  
Tech Regular
Thread Starter
 
Join Date: Sep 2009
Location: Warsaw, Poland
Posts: 339
Default

That's true, it doesn't seem to happen as often with fuel bottle... I would however want to find a solution as fuel gun is much quicker.
I'm pitting usually at 7:30 with fuel left for another 1min or more so no last call refuelling for sure.

Originally Posted by Winner's Circle View Post
I think it is a fat bottom. Try a hot plug and see if that helps.

Lee
I know that it's pretty common problem but it really doesn't seem like the engine is dying because of too much fuel but rather too little. I'll lean it out a bit to see as I'm still on the safe side I'd say. Maybe I'm misjudging it...

As for the glow plug I'm using Picco P5TH which is already a hot plug.
Donat is offline  
Reply With Quote
Old 04-12-2017, 04:38 PM
  #5  
Tech Addict
 
timjs's Avatar
 
Join Date: Jun 2015
Posts: 533
Default

Not wanting to idle is one of the first signs of low compression, could that be a possibility in your case?
timjs is offline  
Reply With Quote
Old 04-12-2017, 05:33 PM
  #6  
Tech Regular
Thread Starter
 
Join Date: Sep 2009
Location: Warsaw, Poland
Posts: 339
Default

Originally Posted by timjs
Not wanting to idle is one of the first signs of low compression, could that be a possibility in your case?
That shouldn't be a problem. The engine still has very good compression, it's about 10L old and the problem was occuring earlier as well. I don't have a problem with idling in general, just when the car is being refueled with a gun.

I asked Ryan Lutz and actually he might be spot on! I asked what is the most common reason of engine dying during refueling with a gun (apart from too rich bottom end).

Ryan's response:
"Fuel guy blocking fuel tank completely with gun.
Hold gun at slight angle to allow air beside it."

That really might be the reason as the Losi gun seals the hole in Mugen tank very tight. I will test that next time and will let you know if it solved the problem!
Donat is offline  
Reply With Quote
Old 04-12-2017, 06:49 PM
  #7  
Tech Elite
iTrader: (98)
 
hairymuffin's Avatar
 
Join Date: Feb 2008
Location: moreno valley, ca
Posts: 2,996
Trader Rating: 98 (100%+)
Default

It's the fuel gun closing the top of the tank, lutz pointed this out years ago to my son. He said mugen did this more often than other brands. He said to not put the gun all the way in the tank,(not touching the tank)voila no more flameouts during fueling. Also helps to rev the engine before you set the the car down
Donat likes this.
hairymuffin is offline  
Reply With Quote
Old 04-12-2017, 06:51 PM
  #8  
Tech Elite
iTrader: (98)
 
hairymuffin's Avatar
 
Join Date: Feb 2008
Location: moreno valley, ca
Posts: 2,996
Trader Rating: 98 (100%+)
Default

Originally Posted by Donat View Post
That shouldn't be a problem. The engine still has very good compression, it's about 10L old and the problem was occuring earlier as well. I don't have a problem with idling in general, just when the car is being refueled with a gun.

I asked Ryan Lutz and actually he might be spot on! I asked what is the most common reason of engine dying during refueling with a gun (apart from too rich bottom end).

Ryan's response:
"Fuel guy blocking fuel tank completely with gun.
Hold gun at slight angle to allow air beside it."

That really might be the reason as the Losi gun seals the hole in Mugen tank very tight. I will test that next time and will let you know if it solved the problem!
I didn't read all your post before I posted mine lol...
hairymuffin is offline  
Reply With Quote
Old 04-12-2017, 07:04 PM
  #9  
Tech Fanatic
iTrader: (3)
 
Join Date: Oct 2008
Location: Houston, TX
Posts: 890
Trader Rating: 3 (100%+)
Default

Originally Posted by hairymuffin View Post
It's the fuel gun closing the top of the tank, lutz pointed this out years ago to my son. He said mugen did this more often than other brands. He said to not put the gun all the way in the tank,(not touching the tank)voila no more flameouts during fueling. Also helps to rev the engine before you set the the car down
I would not even think of that, I would be like damn rich lsn
Evoking1230 is offline  
Reply With Quote
Old 04-12-2017, 07:15 PM
  #10  
Tech Elite
iTrader: (98)
 
hairymuffin's Avatar
 
Join Date: Feb 2008
Location: moreno valley, ca
Posts: 2,996
Trader Rating: 98 (100%+)
Default

Originally Posted by Evoking1230 View Post
I would not even think of that, I would be like damn rich lsn
Lutz will help you out no matter what brand you run
Goof likes this.
hairymuffin is offline  
Reply With Quote
Old 04-25-2017, 08:51 AM
  #11  
Tech Regular
iTrader: (14)
 
bypass911's Avatar
 
Join Date: Oct 2015
Location: Los Angeles
Posts: 274
Trader Rating: 14 (100%+)
Default

When you come into pit, clean it out with full throttle a couple times before fueling.
bypass911 is offline  
Reply With Quote
Old 04-26-2017, 08:12 AM
  #12  
Tech Elite
iTrader: (8)
 
savagesam's Avatar
 
Join Date: Jun 2008
Location: bayside, melbourne
Posts: 2,072
Trader Rating: 8 (100%+)
Default

Seen this many times, crack the top of the guns lid open a fraction and the issue goes away, just work out the best way to keep the lid open a fraction, piece of fuel tube
savagesam is offline  
Reply With Quote
Old 05-01-2018, 07:49 AM
  #13  
Tech Regular
 
stanleyw808's Avatar
 
Join Date: Sep 2010
Posts: 370
Default

Hello Donat and Friends,

Donat, have You figure this flameouts problem out?

I've been having this issue myself. Almost tried everything that I could think off as well but still have not figure this out. Very sad and confusing..

In regards to Mr. Lutz's idea of tilting the point of the gun so that the fuel tank hole is not completely covered, I assume that the idea is to avoid creating a positive pressure to the tank thus pushing more fuel to the Fuel Line than it's suppose to be and flooding the Carburator. At first I thought this might be the culprit, but if You see a common Fuel Gun Design, they put a venting pipes around the fuel nozzle valve for exchanging air inside the tank to be replace by fluid that is coming in. So, the possible of creating a positive pressure might not be very plausible.

But please feel free to share any other idea to avoid this particular flame-out and I will gladly try, whatever it is.

In a very peculiar condition, my problem comes when I move from O.S. B2101 to B2102. I never had this kind of problem when I run 5 engines of B2101.

Cheers..
stanleyw808 is offline  
Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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 On
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service