Help! 50 Titan OS 50 Hyper strange throttle problem

[Rodan]

I was flying with a friend today and he was having a throttle problem that is baffling us:

With the curves set up for a headspeed around 1600 (he's still in the mild FF stage), if he gives it a bunch of collective to climb out, the headspeed is OK until he pulls back the collective. At this point the motor rpm starts climbing, and the headspeed goes up to 1900+. Even after he descends and maintains a hover the headspeed will stay up around 1800 or higher.

Even a mild increase in collective will cause the headspeed to slowly ramp up to overspeed levels.

This is a Raptor 50 Titan, with OS50 hyper. It has a hitec non-digital servo on the throttle, and he's using an Optic 6 tx. No governor. The heli has been flying fine (about 5 gallons through it), although he's still in the learning stages, this problem is new, however.

This has got several of us stumped, and I'm new to glow myself. My 50 V2 is set up on a JR radio, so I can't help him too much with radio setup, but I think it's in the radio, programming or servo. His curves seem OK, and we played with the throttle curves today without really impacting the problem...

Anyone got any ideas?? :dontknow

[Jim Platt]

Sounds like a mixture problem (lean) and also may be agravated by certain mufflers running at that low of a headspeed-----
Jim

[Rodan]

Thanks!

He called me a few minutes ago, and said he found that the original fuel line in the tank had disintegrated, and he was replacing them...

Hopefully that will be the problem. We should find out tomorrow.

[BarracudaHockey]

LOL I was getting ready to type "Replace the clunk lines" when I made it down to your last post.

[Rodan]

Well, the problem continued after replacing the fuel lines. After much headscratching and brainstorming, and a little trial and error... he removed the in-line fuel filter and the problem seemed to go away. He also did a careful inspection this evening, and found a pinhole in the main tank.

We've got our fingers crossed, but it looks like the problem is solved... :bomb:

[BarracudaHockey]

Its best to knock the sharp edges off the frames with some sand paper where the nubs go, they are known for cutting into the raptor tanks.

[Ranc68]

I have had my Hyper50 for about a year and I have had the same problem twice. The 1st time it happened I had so more experienced guys check it out and they tuned on it and it seemed to do better although it still had a higher rpm at hover than my friends Raptor. Anyway, i have flown it for a while like that but it happened again this weekend. It started reving off the charts. I tried riching it up until it was sick rich but still screaming wide open. Took the carb off cleaned everything and set the needles back where the book said to start tuning. I also went into the throttle curves and set point 4 down some. It is much better but still not sure what the problem was to begin with. Oh well, at least I'm flying again.(for now!)