An ongoing problem comes to a head!

[wren1702]

I've been fighting a couple of problems for 2 weeks now and finally figured it out. I've been having a lot of issues with starting, idling, noise and binding sometimes, poor performance sometimes. Had it running pretty good at Huntsville only to come home and find it's not running right again. Tune on it some and get her flying good again. A few flips, flying around and I hit the collective and the engine screams and I lose lift. Hit throttle hold and auto it in. Tear down and find clutch bell is broken, the kicker is that I saw this 2 weeks or more ago and thought that it was machined for a press fit (The break is so smooth, it looked machined). I think this explains alot of the problems I've been having with starting and idle speed from the clutch dragging because of a broken clutch bell.

I think this was caused when I upgraded to the newer style clutch with the one way bearing for the starter shaft. When I first put it back together and flew it the starter shaft was in a bind. I was told to drill out the holes in the frames so that I could line the engine up better and it worked like a charm, but the damage was probably done. A good learning lesson for me!

[flyinfool]

I never saw a failure like that one before.

A few thing to check.
Make sure that you do not have the black washer inbetween the fan and the front bearing of the engine.
When you install the start shaft you have to push it up from the bottom before you tighten the setscrews on the start coupling. If this is not done then the clutch bell and start shaft can move down and drag on the the clutch.
The start shaft is what holds the clutch bell in place.

[wren1702]

Thanks Jeff. So go ahead and stick the clutch bell in and insert starter shaft, install coupling and push up on shaft and tighten grub screws. Then install engine. Is this correct?

What would I do without Helifreak! :D

[flyinfool]

This is correct.
You want just a hint of vertical free-play in the start shaft so there is room for heat expansion as the engine heats up.

I have not yet found a way to put on a start coupling without dropping the engine to push the shaft up.

[heliengineering]

Hi:

I found same issue in one of my others model - EVO 50 long time ago and when I try to determine the cause only found that its possible by over TORQUE the gear to the bell. Remember its necessary hold the bell to tight the gear and its possible tight too much... :arggg:

Same of you, I notice the damage by the "ring" noice when start the engine.

I never have this issue in my Stinger's, but I'm more carefully when I install this gear on all my models, just add little quatity of blue Loctite and install by hand (Any tool).

regards

Julio

[flyinfool]

When installing the gear in the bell it is not necessary to put a great tightening torque on it, finger tight is enough.
The direction of rotation is always trying to tighten the gear into the bell when in flight. I do not even use loctite on this joint. It can not possibly come apart.

[OUT OF CONTROL]

I had the same thing when I got my first stinger. The problem on mine was the fan it was 1 mill longer than the fan we had here at the shop. I replaced it and havnt had a problem since!!