Trex 600 problems

[fudded]

Last week while flying my trex 600, the os50 seemed to over speed loads, the engine got really hot, so I packed up and came home. So this week while I had it to bits, I took the chance to swap the engines, so I now have fitted it with the os55 from my rappy, while I was at it I put in a new clutch liner, the clutch is only a couple of flights old, changed all fuel lines including clunk line. Went out yesterday got exactly the same problem, only hovered yesterday, and the engine nearly fried.
My throttle curve is 0,20,40,60,80. Pitch curve is -4 low 0 mid +10 high.

What could I be doing wrong ?

Sean

[moonmanflyer]

Are you using an engine govener Sean?
The engine will tend to overspeed easily on a 50 if not carefull, and that will cause it to get hot.
If you are running a gov it sounds like it might not be working properly

[zoombolt]

I see you've changed over all the fuel tubing, which is where I would have started from.
Have you checked the throttle linkage & arms. Sometimes they can come loose. It may also be the throttle servo so may be worth a swap over.

[fudded]

I use a revlock 30, but I tried it "armed and unarmed" yesterday. The revlock appears to be working, it is a brand new sensor.

Sean

[fudded]

I see you've changed over all the fuel tubing, which is where I would have started from.
Have you checked the throttle linkage & arms. Sometimes they can come loose. It may also be the throttle servo so may be worth a swap over.

I have a spare servo, I will give that a try.

Sean

[barney]

Governer/Pickup issue. Sounds very much like its not engaging. With a governer set it so your Normal mode is nice and Low, maybe 1600-1700 so you always get a big Audable change as soon as you go to Idle 1/2. You know instantly its working or not

Other possibilities would be your pressure line cut or blocked. On a 600 the canopy tends to push against the pressure line. It can get a little cut at the Exhaust nipple (I always cut a small bit of the canopy away as the slighest rubbing will cause this..just run a smear of epoxy along the canopy edge afterwards to seal it from the exhaust gasses)

Exhaust Nipple blocked, just poke something through.

Did you change the fuel line in the tank???

Try not to use pliers for fuel tubing as it very easy to Nip when fitting.

Clean the filter the Aligns use a fine mesh.

Brian

[fudded]

Stupid Stupid Stupid !!!!

Barney many thanks, just checked a couple of things you suggested, my inline fuel filter was pretty gunked up, why I didnt check it when replacing the fuel line I dont know . Im guessing this could cause a fuel shortage and cause a lean run. Im putting it back together will try a flight later, weather permitting.

Thanks for all the replies

Sean

[coptermanic]

Yes, I have been having a similar issue of "leaning". I replaced EVERYTHING:
filter, tubing, clunk lines, etc. Even a small split in your tubing would cause a problem. Also worth dropping the donkey to check for loose head bolts, the gasket, and to get one of those high-pressure air jets to blow the carb, make sure no bits blocking the needles.

[fudded]

Ok gents, Im absolutley baffled on this, been back out, no difference whatsoever. I disabled the revlock, I rechecked all the pitch curves, I reset the engine to 1.75 turns on both needles. Throttle curve of 0,20,40,60,80. After 30 seconds of hovering the engine is HOT.
I am kind of ruling out a fuel problem as this is the second engine its happened to, and I have replaced all the plumbing including clunk line, I have checked the exhaust nipple, no blockage.
One thing that I have noticed it takes an age for the clutch to engage, the engine is screaming before I lift off.
Is it possible I could have some slippage between the clutch and liner (both are new), it really does seem the engine is working to hard.

Thanks

Sean

[barney]

Is you governer audably cutting in and pegging the headspeed back. i.e if you switch between Normal/Idle 1 and back it drops the headspeed?.

The latest clutch bells do have more clearance like the early 600N's for some reason and had one myselfthat engaged very late.
Its easy to check though but you need to drop the motor. 2-1/2 wraps of electrical tape on the clutch shoe and it should just slide in a little on the tight side.

You can re-use the current liner as they easily prise out with a sharp blade. You then epoxy in an extra layer of paper behing the the liner. Use the tape on the clutch shoe as above to set the clearance. You can gently splay the frames by removing the servo tray bolts up front and pull the start haft/bell assembly out to make it easier to work on.

Brian