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View Full Version : Great day flying but.........


mewsikman
01-27-2008, 05:57 PM
Hey guys,

Today the weather was perfect... Nill wind, bright blue skys and the sun was behind me :).....

Today was the first time that I have been able to push my heli and myself to the max since my upgrades....

The upgrades were :- Metal blade grips, Metal washout arms, Align 50 pipe ( WOW ) and frame stiffners...

My problem is the mixture is just all over the place now and I just can't understand whats going on.... I started flying today with the needle mixture out about 1 turn.... fired up ok, for some reason everytime I start it from cold it feels almost like a hot start I have to click the throt tab ( DX7 ) down at lease 3 - 4 clicks to stop it trying to turn to the main blades..... But once it has warmed up the idel is ummm how to put it nicely SH*T always up an down, iv have tryed new plugs they work for like 2 mins then back to normal.... ill come back to that in a min...

Go out flying with the needle set around 1 turn out from fully closed... Doing stall turns, invert circutes, loops, rolls and tic tocks.. I then crack out my new temp gun to check the temp on the back plate, was running around 95 F so I thought that I would richen it up abit because I am only using 16% with 18% lub.... Did the same style of flying brought her down hit throt hold an the rmp started to drop nicely but then did the tell tale sign of running lean with the jumping on the rmp.. richened it up 2 clicks at a time, repeated this over an over I have just ended up at 1.25 turns out, and for some odd reason when I hit throt hold it started to speed up the rotors almost like it was running lean then started to die back down….. I then checked the temp of the back plate it was at 100.7 F and the cooling fins were at 147 F…. You should have seen the oil all down the tail boom look like liquid sh*t all down it, was everwhere inside the canopy and I have never had this before… I know this is the joy of having nitro but it looked like the engine had just taken a whole packet of laxatives…

I have checked an made sure that my pipe is nice and tight, used both brass gaskets like it says to, I checked the plug to see if coil was distorted or grey…. Nope nice an shinny new, but the plug looked oily and so did the crown of the piston, don’t know if that’s normal???

Right back to the idle speed, I just don’t know how to descibe it…. When I set her on the ground and powered down the idle was fine for about 4 secs then dropped off like it was running to rich but I have no idea whats going on… I will try an do a video asap just so you guys can see….

Very sorry that it was soooooooooooo long but I tried to cover everything

Many thanks

Alex

JoeScott
01-27-2008, 07:25 PM
Check the head and backplate bolts for tightness. Also check to make sure the carb is sealing correctly to the crankcase and the carb mounting screw is tight. Check your fuel lines for pinholes, especially the clunk line in the tank. If your running a fuel filter (you should be!) check for debri in the screen.

mewsikman
01-27-2008, 07:47 PM
ok cheers will do

WayneBrown
01-27-2008, 08:31 PM
Sounds to me like your idle mixture is screwed up.
Here's how I tune the idle;
Warm engine to operating temp,
pinch fuel line at mid-point between tank and carb,
if RPM increases then dies, RICHEN the idle,
if RPM stays constant for more than a 5 count, lean the mixture,
Fly and adjust main needle settings.
Following above steps, recheck and reset the idle.
You will likely never have to touch the idle again.

brgsstm
01-28-2008, 08:54 AM
Sounds to me like your idle mixture is screwed up.
Here's how I tune the idle;
Warm engine to operating temp,
pinch fuel line at mid-point between tank and carb,
if RPM increases then dies, RICHEN the idle,
if RPM stays constant for more than a 5 count, lean the mixture,
Fly and adjust main needle settings.
Following above steps, recheck and reset the idle.
You will likely never have to touch the idle again.


+1, i messed with my idle screw this weekend as I was having similar problems and hey presto, after a few degrees leaner the problem was gone :thumbup: I find that with the Align 50 pipe you get a sort of gurgling or spitting noise when too rich on the idle screw.

P.S. I keep hearing these brass washers mentioned. My Align pipe came with 2 red coloured ones and I only use one. Is this right?

Thanks

Tom

mewsikman
01-28-2008, 01:00 PM
Yea I know what you mean about the gurgling sound when its rich but mine doesnt do that.... The best way I can descibe it is, it sounds like someone just stuck their finger in the barf tube...

mewsikman
01-28-2008, 05:08 PM
Hey guys,

Many thanks to you that have replyed an to JoeScott, you were right... A couple of the head bolts were loose.. Just been outside an fired it up 1.5 turns out on the needle valve to be on the safe side, then slowly worked in.. The rmp did drop a few times while I was tuning....

I wasn't able to fly because its 10 at night so I thought that I would just flick it into idle 1 & 2 to sim a 2 min flight....Just to help it get upto temp..... But all is well I hope

Many Thanks
Alex

JoeScott
01-28-2008, 06:35 PM
Cool Alex, glad you found it. Also make sure you adjust your idle mixture as Wayne instructed, thats a good method. Your going to like that Align pipe! :thumbup:

Tom - Haven't seen the red gaskets your talking about, but if its a paper type gasket you'll be fine with just one.

brgsstm
01-29-2008, 05:16 AM
Tom - Haven't seen the red gaskets your talking about, but if its a paper type gasket you'll be fine with just one.

Thanks, they are a paper type. Mewsikman great news, glad i removed and threadlocked mine before I installed it now :thumbup:

While we are on the subject, is it possibel to buy replacement gaskets for the align pipe?

Thanks

Tom

frogbmth
01-29-2008, 12:12 PM
Won't the gaskets for the hyper from QuickUK fit?

Andy

brgsstm
01-29-2008, 05:29 PM
Won't the gaskets for the hyper from QuickUK fit?

Andy

Hope so, cheers i'll check them out,

Tom

mewsikman
01-30-2008, 12:50 PM
Sounds to me like your idle mixture is screwed up.
Here's how I tune the idle;
Warm engine to operating temp,
pinch fuel line at mid-point between tank and carb,
if RPM increases then dies, RICHEN the idle,
if RPM stays constant for more than a 5 count, lean the mixture,
Fly and adjust main needle settings.
Following above steps, recheck and reset the idle.
You will likely never have to touch the idle again.

I followed the advise of Wayne, but its still doing it....

Pinched the pipe like he wrote, counted 5 secs then the rmp started to rise then it cut out. but it is still doing it.... I can't understand why it is doing this.... This all started when I changed the throt servo ages ago....

Can anyone please help???

JoeScott
01-30-2008, 06:14 PM
This all started when I changed the throt servo ages ago....

Sounds like that might be your problem. Even if the throttle servo acts normal on the bench that doesnt mean that it isnt acting up while your flying due to engine vibration, etc. Swap in another servo and see what happens.

mewsikman
01-30-2008, 06:59 PM
ok will do.... Thanks

Forced_Induction
01-30-2008, 07:26 PM
mewsikman,

It sounds like how mune was running when i first got it going. I notice you are using 15% nitro fuel. do yourself a favor, go buy a jug of 30%, richen it up half a turn on the needle, retune and try it again. mine was a pain in the ass to tune on 15%. half of every flight was just trying to get it running right. It wouldnt hold rpm in a hover either. i would bring it up to a hover at the right rpm, fly some stall turns and circuits and back to a hover 400 rpm higher than it was before. and it would hold that rpm until i spooled it down a bit, then it would hover normal again.

All my problems claered up using 30%. give it a shot.

mewsikman
02-01-2008, 07:49 PM
This is what my heli sounds like after I have been flying it around then letting it idle for about 5 - 8 secs

http://uk.youtube.com/watch?v=V4EKKH3KbWg

It starts to sound like mine from 56 secs onwards