News:



  • March 28, 2024, 10:22:47 AM

Login with username, password and session length

Author Topic: LA 40 woes  (Read 1466 times)

Offline Allen Eshleman

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 809
LA 40 woes
« on: April 12, 2021, 07:33:47 PM »
I have a wonderful LA 40 (so far).  It started easy and ran very economically.  So far this year, I have started it twice.  By using the needle I can get it to a passable 4 stroke.  When I turn it one more notch (so to speak) and it breaks into a wet two stroke, it stops.  Randy Smith needle. Any thoughts on what might be going on?

Online Dan McEntee

  • 23 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 6824
Re: LA 40 woes
« Reply #1 on: April 12, 2021, 07:42:11 PM »
  Do all the usual. Clean the needle valve, change fuel line, fill the tank with fuel and let it sit over night or longer to loosen up last year's left over oil sludge.  Flush out with some acetone or thinner and try again. Then check out the glow plug, at least give it a good visual inspection, and try a new one if needed.
   If nothing else was changed over the winter and it just sat, that's all you should need to do.
  Type at you later,
    Dan McEntee
AMA 28784
EAA  1038824
AMA 480405 (American Motorcyclist Association)

Offline RandySmith

  • Administrator
  • Trade Count: (0)
  • Admiral
  • *****
  • Posts: 13747
  • Welcome to the Stunt Hanger.
    • Aero Products
Re: LA 40 woes
« Reply #2 on: April 12, 2021, 10:26:23 PM »
YOu should  check teh glow plug,  are you running muffler  pressure ?

Offline Allen Eshleman

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 809
Re: LA 40 woes
« Reply #3 on: April 13, 2021, 06:32:53 PM »
I changed the glow plug and it is running better. It 2 cycled longer.  But, I also changed the tank - it only runs to half empty.  I will tinker with the tank and plumbing some more.  I have not been using pressure.  The muffler is regular supplied muffler.  It is swinging an 11/4 prop right now.  I usually use 10 1/2 x 4 1/2.  This is all on the ground.  I haven't attempted to fly it yet.  I just remembered that it has a black plastic back plate.

Online Dan McEntee

  • 23 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 6824
Re: LA 40 woes
« Reply #4 on: April 13, 2021, 08:24:04 PM »
I changed the glow plug and it is running better. It 2 cycled longer.  But, I also changed the tank - it only runs to half empty.  I will tinker with the tank and plumbing some more.  I have not been using pressure.  The muffler is regular supplied muffler.  It is swinging an 11/4 prop right now.  I usually use 10 1/2 x 4 1/2.  This is all on the ground.  I haven't attempted to fly it yet.  I just remembered that it has a black plastic back plate.

      Just make sure the screws for the back plate are tight. Don't over do it. If suspect a leak, remove it and apply a thin coat of some silicone gasket sealer or something similar, and replace and tighten down carefully. If you are careful, there is no reason to change the back plate. The metal replacements just let you really crank the screws down, but still need a gasket and/or sealer. I have a few LA.40's in service with plastic back plates and no problems.
     Make sure you flush out the needle valve assembly and make sure no gink is stuck in there.
    Type at  you later,
      Dan McEntee
AMA 28784
EAA  1038824
AMA 480405 (American Motorcyclist Association)

Offline Allen Eshleman

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 809
Re: LA 40 woes
« Reply #5 on: May 06, 2021, 09:17:56 AM »
It's running well again.  The Glow plug was the problem.

Online Dan McEntee

  • 23 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 6824
Re: LA 40 woes
« Reply #6 on: May 06, 2021, 10:36:30 AM »
  Glow plugs are not an exact science. They can last for 2 runs, 2 months or 2 years some times!! Using good quality plugs like those mentioned often such as the Glow devil R/C long, Thunderbolt, Merlin hot plugs when you can find them and SIG R/C long.  It isn't worth losing a model over an 8 dollar plug!
  Type at you later,
   Dan McEntee
AMA 28784
EAA  1038824
AMA 480405 (American Motorcyclist Association)

Offline Allen Eshleman

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 809
Re: LA 40 woes
« Reply #7 on: May 07, 2021, 07:28:20 AM »
Very true Dan.   I do use the quality plugs.


Offline Allen Eshleman

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 809
Re: LA 40 woes
« Reply #8 on: May 07, 2021, 05:10:26 PM »
I just want to say that the LA 40 gave me three well running flights today. Two seven plus minute runs and one 8 minute run with a three ounce Hayes tank. It was singing a happy tune today!

Offline Steve Helmick

  • AMA Member and supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 9920
Re: LA 40 woes
« Reply #9 on: July 25, 2021, 12:40:12 PM »
Seems to me like 7~8 minutes run time on 3 oz is a bad deal. I think you need to put at least 4 oz of fuel through it for those run times. More fuel = more oil and cooler running. That said, most plastic tanks hold more fuel than the label says they do. I'd also wonder if you don't actually have a 4 oz Hayes tank, since the 3 oz is apparently out of production.  ??? Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.


Advertise Here
Tags:
 


Advertise Here