dissappointed

[Delarado]

A little hint with the OS105 - Mine came and I didnt check the needle settings. They were waaaay off (Much leaner than the manual said they should be)

Once i reset them to the stock settings, the heli wouldnt even spool up properly. I actually burnt out a clutch trying to get it to spool up, I didnt realise what was going on and the clutch was slipping constantly even though I was flying just because the engine was so pig rich it didnt even have the power to reach a proper RPM and engage the clutch properly. Run it with the stock needle settings by all means, but just make sure your clutch isnt slipping or anything stupid when you do. I think mine was caused by a combination of being really rich and a low throttle curve. I had to lean my mid 8 clicks from 1 turn out just to get the thing off the ground properly.

Stock settings are a full turn out on the mid and 2 and a half on the high I think. So far I've got down to 1/4 turn out on the mid and just over 1 turn out on the high and its still really rich on the high end (I think) Im running the small shim in the engine and 20% optipower with a standard #8 OS plug. If your around dagenham way we could go fly sometime, Im in watford.

[vinny155]

yeah be interested in flying sometime,havnt really been out in the last 7 months,new addition to family but going to make up for that this holiday ,i know what you said above will make sence nxt week...lol

[Delarado]

Yeah it will mate

Theres two sticky out screws on the side of the engine, one controls how much fuel goes into the engine in the mid range of throttle, the other how much fuel goes in at the top end (When the engine is wide open throttle)

You screw them in to lean them out (Less fuel) and unscrew them to richen (More fuel)

They have these little things on them that interface with the grooves in the screws that make them "click" as you turn them, and you use clicks as your unit of measurement when tuning.

The manual states the mid fuel screw should be set at one full turn open from fully closed when the engine is first used. This is fine and it will run like this, but I found mine was so rich that it'd barely get off the ground, there was that much fuel going in that it couldnt burn it all and it was actually hindering the performance hugely, even just getting into a hover. I had to lean it out 8 or so clicks ( About 1/4 of a turn) before it'd even spool up reasonably and make the heli take off.

Until the engine was lean enough to not drown itself in fuel in a hover it wouldnt pick up speed engough to go fast enough to make the clutch shoes spin out and grip the clutch bell properly. Because of this, i burnt out a clutch liner through slippage!

[tonystevens]

[QUOTE=Delarado;946306]

Stock settings are a full turn out on the mid and 2 and a half on the high I think. So far I've got down to 1/4 turn out on the mid and just over 1 turn out on the high and its still really rich on the high end (I think) Im running the small shim in the engine and 20% optipower with a standard #8 OS plug.QUOTE]


I dont know the 105 but 1/4 turn out on the mid sound a bit too lean to me, considering your engine isnt that old? what's OS's guidelines on final needle settings once run in?

[Delarado]

p.s the idea with a nitro engine is intially run it very rich and tune it gradually to lean it out. You do this to help coat all the engine internals with the lubricant that is in the fuel, and also to gradually heat up the engine, to give it heat cycles. The less fuel going into the engine, the hotter it will get. The hotter it gets, the more it expands. The more it expands, the tighter the interface between the piston/piston ring/piston liner. This will wear away over time.

If you go too lean the engine will get very hot and everything will expand so much that it will wear away so much that itll start to lose compression when its cooler and be difficult to start, not make great power etc. Thats why its important to gradually lean things and to never go over-lean because you will permanently damage your engine if its run lean. There is no damage you can do to the engine itself though by running it too rich.

[Delarado]

[QUOTE=tonystevens;946318]

Stock settings are a full turn out on the mid and 2 and a half on the high I think. So far I've got down to 1/4 turn out on the mid and just over 1 turn out on the high and its still really rich on the high end (I think) Im running the small shim in the engine and 20% optipower with a standard #8 OS plug.QUOTE]



I dont know the 105 but 1/4 turn out on the mid sound a bit too lean to me, considering your engine isnt that old? what's OS's guidelines on final needle settings once run in?

They dont seem to have any in the manual. I know it does seem lean, stuart has 1/4 out on the mid and 1 on the high on his 105 in his G4 though running the rapicon fuel, 20% just like me. There seems to be a wide range of settings for these engines, I've seen some people saying they are like 6-7 clicks out from closed on both needles and it runs great! Others much more. I Dont really know how to tell to be honest just yet with the mid, but theres plenty of smoke out of it when just flying around or hovering (loads and loads actually, much more than I get when i go full throttle) and the backplate is pretty much cold to the touch after a period of extreme tail in hovering

If I go full positive collective and then go back to mid stick, theres a noticeable increase in the amount of smoke from the exhaust and the head speed recovers instantly. People still laugh at me at my club because of how smoky it is in a hover

[bladeboy400]

Vinny check the head bolts on the engine mate from factory i have had these come loose also

[vinny155]

cheers john,getting there now,learned about the clutch and liner today ,makes a change from building electric heli's,quite exciting stuff

[bladeboy400]

I'm green mate as the others have said don't take it that it will be right out the box try bolts etc put the needles to factory and then I would open another quarter turn then start your tuning after a tank hovering

[Delarado]

I wouldnt recommend opening a quarter turn from factory settings.

As mentioned, the manual lists a factory setting for the needles valves. Check that this is what they are at out of the box (Mine was not)

After this you can run it. Mine wouldnt even take off with the stock settings as per the manual because it was so pig rich. Open the valve another quarter turn and I doubt you'd even get the blades to spin :P