Odd problem
 

I have a West 50 2 stroke and one of their throttling pipes in a profile. I can't find the prosynth fuel they recommend so I use a good quality 5% nitro mix with good quality oils. The problem is that I can get the engine to start fine and run fine, but the second I take the glow clip off it wants to die and is extremely tempermental. With the glow clip on the engine runs perfect throughout the throttle band and responds smoothly, its just the second I take it off that it gets messy. The engine is still slightly rich as it is not run in but theres plenty of smoke and oily residue so I don't think I've been running it lean. The glow plug has been changed and I used the recommended plug from weston uk.
Any ideas what the problem could be? I can't fly until I fix it!

RE: Odd problem
 

The west 50 in made in Austria maybe a retagged Webra??what is their fuel and plug recs. martin

RE: Odd problem
 

Those symptoms are indicative of a bad plug, too cold plug, mixture too rich, or too short pipe header. The engine also may not be broken in yet. If it's an ABC/N type, break it in at a only slightly rich two cycle. Lean it out, and back it off until the sound changes and break it in there. It needs to get up to operating temperature to properly break in.

Dr.1

RE: Odd problem
 

The plug I am using is one of their medium heat plugs that was recommended by them. The fuel they recommend is their own prosynth 10% mix http://www.westonuk.co.uk/index_032.htm.

RE: Odd problem
 

Usually if the engine dies when you remove the glow....the fuel is bad. If the
engine starts and runs, it indicates that the plug is OK (maybe not perfect)
and the fuel system is Ok (maybe not perfect). The plug cannot continue the
catalytic reaction with the methanol without the power of the battery.

Change the fuel, make sure it is fresh fuel. ;)

FBD. :D

RE: Odd problem
 

I changed fuel to fresh fuel and the problem persisted. was thinking of trying my powermaster 30% fuel I use for my YS engines but I think that it would probably be too much nitro for it to handle.

RE: Odd problem
 

What do you mean by ''extremely tempermental''
Is it at idle when you take the battery off if so you might be too lean on the low speed also try leaning out the high speed till it just cleans up then richen it up some
keep the tank at least half full during break in some piped engines don't make great pressure and it gets harder for the engine to draw fuel as the tank level drops

RE: Odd problem
 

I've tried taking the glow clip off at most throttle settings and each time the revs will die down and the engine doesn't really respond to throttle inputs. It then dies...

RE: Odd problem
 

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Because of the nature of a glow two-stroke to run on the left overs of the previous fuel/air charge along with the newly inducted fuel/air charge, the over all octane rating of the fuel is grossly reduced. This makes the glow two-stroke very sensitive to compression ratio and fuel octane. Two-strokes will go into detonation much more quickly than a four-stroke running the same fuel. This is why four-strokes run so well on high nitro even without modification, while a glow two-stroke will quickly fry.

I'm sure that the resident engineers can pick apart the previous paragraph with ease, but the basic premise (what I mean, not what I said) remains true. With that said, please feel free to comment and critique.

If you are going to run your engine as rich as one runs a heli engine, then the 30% nitro won't be a problem. However, if you try to run the engine as lean as we airplane types typically tune our engines, you can end up with an expensive pile of junk (paper weight) in no time.

In the olden days of tapered bore engines, it was understood that one should never run higher nitro in a tapered bore engine than one intends to use from that point forward because, once the liner was flared to a new set with higher nitro fuel, the only way to get the liner fit back to where it was is with a new piston and liner. Before I tried 30% nitro in that glow two-stroke, I would fire off an email to Weston and get their opinion.


Ed Cregger

RE: Odd problem
 

Hi!
To me it sounds as if you use too much nitro!
Try 5% nitro and 15-20% oil ...You mix yourself??

What APC prop do you use? Webra engines doesn't need any running in! They throttle perfectly from the start.

RE: Odd problem
 

If it is dying out as you now describe it is way too rich. It runs pretty good with
the glow connected, by the fire goes out when you remove the glow.

Set the high speed at full peak wide open, then just richen it up a couple clicks for
now. Keep the glow igniter on....drop it to a medium to fast idle, not a slow idle.
Carefully adjust the idle screw to lean out the mixture (presuming it is too rich)
while the engine is running with a long, skinny screwdriver. Set the engine to where
the engine is running the fastest at idle. You may have to drop the speed a bit if the
engine starts running really fast, to get the proper setting.

When you get the engine running the fastest speed at idle, it should work pretty good
bringing it back up to high speed (transition). Now take off the glow and see if it continues
running. Reset the high speed as normal.

The engine should run pretty good at this point. See what happens now.

FBD.