Raptor resurection

[w3bbo]

Well it's sunny outside, got all my starter kit sorted and the damn thing won't start. Well it will for about 5 seconds before dying.

Here's the problem:

It starts up for about 5 seconds
It usually needs me to pinch off the exhaust to pressurise each time.
Once started it will either:

a) die almost immediately
b) Stall after about 5-10 seconds with revs slowly dropping.
c) Stall immediately when I raise throttle a little.

I have to have the throttle about midway (on the TX) for it to even start. It sounds like its choking or something. When I start it by pressurising the muffler, it coughs a bit then the revs immediately raise upon release but then slowly subside again to a couch and splutter before it stalls. When it starts coughing the engine appears to go into reverse (main gear/cog spins in opposite direction) before stalling.

Glow lighter charged up fully (brand new) so its not that.
Both heli and TX charged to the max.
Tried adjusting the main needle making it richer and leaner (all adjustments between 0.5 and 3 turns out) - 1.75 turns seems to get me going for the longest with a good amount of smoke.

I'm running an Irvine .39 with Rapicon 15%. I haven't changed the glow plug yet so that is next on the list. Could it be a bad plug?

Any advice you guys can give?

[w3bbo]

Ok, I've solved that problem (it was the low-end needle setting - too lean).

Next problem I have is the fuel. The fuel in the tank has changed colour from bright pink to a murky brown colour after half a tank. Also there is oil coming from the muffler which is a treacle like colour - is this normal?

[w3bbo]

Are there any clubs close by (Stockport/New Mills)?

I went to the High Peak Aero club today but there was no-one there - or perhaps I got the wrong place? Either way being the impatient person I am, I decided to break out the heli anyway and managed my first 'hops'. I could really do with someone giving the heli the once over though before I attempt my first proper hover to make sure my heli is setup correctly. I 'think' I have the pitch and throttle curves setup right for hover but again, not having someone else to double check is making the whole process a little nervy.

I don't mind travelling and will re-emburse your time with beer of course

Anyone offer a n00b help?

[RotorBlade]

Shame you are so far away - if you are travelling over to the East side of the UK (South Lincolnshire) - let us know.
There's a bunch of people over here who could help you.

[BenScoobert]

Let her run a couple of tanks through rich and flush her out a bit.
I have a raptor and could help you with the tx settings, but I'm not really a nitro man. Had 4 in my lifetime on various cars and a heli.
How many mixture needles does it have? 2 or 3?

[getting100]

You need to go to hell-e cats to get help to set it up good lads they fly at dandy farm .Mill Lane Adlington. SK10 4LF . they fly there at weekend i would go after 1.00 pm to be sure someone is there Dave would be the man

[w3bbo]

It's a two needle irvine .39. I seem to have sorted it now. Cuts off at the 4 second mark when fuel is restricted but I can only go on what I have read here, raptor technique and the net. Like I said, could really do with someone with experience to check it over.

Hell-e kats sounds like a plan! Have you got a link to Dave's profile? Is he a member here?

Cheers for the heads up. Can't wait to fly for real as there is only so much realism a sim can provide!

[w3bbo]

Still not had chance to get up to Hell-e-kats due to lots of weekend work and family commitments. I have however been having a blast this past week learning to hover. I also bought a new TX/RX setup the other week too - Spektrum DX7s with AR8000 combo. It's a much nicer piece of kit than the Futaba 6EX, even in my novice hands!

I have my pitch curve set to 0%-35%-47%-59%-71% with Throttle curve at 10%-40%-50%-60% which hovers the heli nicely at middle stick.

I have encountered a couple of issues that have me perplexed though:

1. Tail twitches ever so slightly to the left every 3 or 4 seconds meaning I am having to correct this constantly even though the gyro gain is set to 100% (heading hold).

2. Engine is tuned great on the ground and gives off good smoke, idles well barely engaging the clutch and seems to give a good amount of power when revs rise to hover speed however after less than a minute of flying the engine seems to lean out (very little smoke) - still handles great though.

The two may be connected in that when the tail twitches I get a quiet 'pop' sound from the engine. I have tried richening the high end needle some but the heli loses power on lift off and begins to splutter. I did manage to get the mixture right (?) but the heli was bobbing up and down all over the place and was a pain to control.

Anyone have any ideas on what to adjust/change next?

[BenScoobert]

drop gain, try 60 or 70, 100 will be too keen

[Steve]

Tail twitching can be caused by many things, but the most common is engine tuning. When the engine peaks on a cycle, it gives a wee kick and the gyro has to compensate. I wouldn't worry about it too much.

[w3bbo]

drop gain, try 60 or 70, 100 will be too keen

Thanks.

I tried 70 but it made no difference, tail still kept creeping to the left in minute increments. I'm using the GY401 and the light is constant on so it's deffo in HH. I'll drop it down another 10 and see what happens.

Tail twitching can be caused by many things, but the most common is engine tuning. When the engine peaks on a cycle, it gives a wee kick and the gyro has to compensate. I wouldn't worry about it too much.

So the tail twitching out and engine no longer smoking is normal?. I'm just fearful I'll kill the engine by it running lean.

[cjcj1949]

Do you have the yaw control (or rudder) trim set to zero. For heading hold to work the gyro needs a pulse width to use for zero yaw. The 401 will accept a range around zero but zero would be best. You could try rate mode as well. Heading hold isn't much of an advantage unless you have wind or you are moving the heli sideways. You could also look at the the gyro mounting pad.

This thread is very interesting because a friend of mine is doing the same as you, or will when he gets the time.

[dave j]

No smoke from a nitro engine isnt normal, im only learning but my heli smokes alot and runs really well i was told to run it like that as smoke means oil wich is good for the engine or mabee i have been advised wrongly

[w3bbo]

No smoke from a nitro engine isnt normal, im only learning but my heli smokes alot and runs really well i was told to run it like that as smoke means oil wich is good for the engine or mabee i have been advised wrongly

Yeah thats what i thought.it smokes a lot at first when taking off but seems to lean when in hover. If i land then take off again i get smoke on take but again, very little once stable in hover.

Regarding the rudder problem: trim and sub trim both zeroed. Gyro pad is in perfect condition.

[BenScoobert]

Yeah thats what i thought.it smokes a lot at first when taking off but seems to lean when in hover. If i land then take off again i get smoke on take but again, very little once stable in hover.

Regarding the rudder problem: trim and sub trim both zeroed. Gyro pad is in perfect condition.

Could it be something limiting flow? So it's fine at low flow/power but when you ask something from it, it is struggling and leaning.