Can lean low speed needle damage engine
 

Well I was using my plane in low throttle, driving it around to get a feel for it, and the engine all of a sudden stopped and wouldn’t start using a my electric starter ,which could not produce the necessary force to turn it over. Is there anyway a lean low speed needle setting could seriously damage an engine or is the starter damaged cause I can still turn the engine over by hand ?Oh and i leaned it to the point where sudden acceleration would not stall the engine, i didn’t make it lean as the limiter allowed. Oh and i have an evolution nx 1.00.

RE: Can lean low speed needle damage engine
 

Generally, if your engine doesn't have transition problems, you probably have the low speed mixture pretty close to right. If the engine is brand new, it may not tolerate low RPM very well until it is broken in well enough. Check your glow plug first and make sure it is not fouled out. A lean run can destroy a glow plug pretty quick. If the glow plug is not lighting up, you may be flooding the engine with fuel. The starter may simply not have the power to turn over a flooded engine (nor should you try). Does the engine start when you flip it by hand (using a chicken stick, or broom handle, or anything to protect your hand)?

RE: Can lean low speed needle damage engine
 

As Russianflyer says, your most probable problem is a burnt out glow plug. Very often new engines are hard on glow plugs until the engine is broken in, probably because of metal particles created during break in foul the plug.

RE: Can lean low speed needle damage engine
 

Have you charged your starter battery? It may simply be getting low. It may not measure low except under a load, just like we check RX batteries under load.

RE: Can lean low speed needle damage engine
 

Let's take this in context...

Your electric starter would not turn it over, but you had no problems turning it over by hand... it's a new engine as well...


So, your starter ( not the glow ignitor! ) is not fully charged!

If you have one of those 7Ah or larger batteries, you may have to charge it up for several DAYS.... in my case mine takes almost a week for a full charge... as I'm running a 27Ah battery charged off a 900mAh charger.



You were "driving it around"... the NX limiter does not permit you to run the engine too lean.


So the engine was still TOO RICH on the low end ( which is typical for the NX 1.00 at first, until it is fully broken in... ) even though you have it set not to bog down on run up.

Since you were running it around at almost idle the engine got too much fuel over time, and died out...


Been there myself with this particular engine.

The idle will not really smooth out until you've run a couple of gallons of fuel through it. Until then you'll need to keep the idle a bit higher than normal ( sometimes risking hot landings ) so as not to stall it because of too much fuel.


Doesn't sound abnormal at all.

RE: Can lean low speed needle damage engine
 

what brand glow plugs do you guys recommend.

RE: Can lean low speed needle damage engine
 

I'm using the "Fox Miracle Plugs" in mine, and yes they are longer for four strokers...

The stock plug it comes with is a longer plug.

RE: Can lean low speed needle damage engine
 

To answer your question, a too lean low end setting can damage your engine, by reducing fuel flow so much that you cannot get a rich setting on the hi speed needle. Running it lean at low speed shouldn' do any harm; too lean and it will just quit.