Oscillation and slight tail wag with new Revolution pipe

[rpchus]

Hey, I've got a strange problem that just started happening with a new Revolution .30 pipe for my Raptor 30 v2 with the TT .39
When the motor spools up to hover and above, I get an oscillation noise (I guess its a "wah wah wah" that speeds up and slows down but NOT in tandem with motor OR head speed). I can't pinpoint it to a particular head speed (I'm not in idle up mode), but it will completely disappear if I re-attach the stock muffler. Once the Rev. pipe is back on, the oscillation returns. I also notice that the tail "wags" slightly to the beat of the oscillation - faster or slower.

So, what is this new pipe changing that could be causing this? Or could it just be the pipe? I replaced the aluminum gasket with a hand-cut cardboard one - not much change. Not sure if it is even gasket related.

I'll see if I can get a quick vid to upload this week.

Any other pipe that is recommended for my setup?

Thanks
Rick
R30 V2 TT.39
JR 6102 w/ 500 gyro
537s & 810G on the tail
can't wait to upgrade these...

[alexander]

Did you readjust the fuel mixture for the muffler change?

[rpchus]

Alexander - thanks for pointing out such a simple oversight.
No, I haven't yet but will do so and report back on the results. I am assuming that it may be running lean? I am new, however, and am not sure how to decide when it is "IN" tune. Any help with a TT .39?

Rick

[rpchus]

After a frustrating day at the field trying to adjust the TT39 with the Revolution Pipe, it was suggested that the pipe must be TUNED, which is causing it to run outside it's preferred RPM range at hover speed. I did notice that as I was richening it (it was originally way too lean), I got to a point when the throttle was above hover speed and it seemed to run OK above half stick - and the climbing power was outrageous compared to my stock pipe. After that point, it got too rich and was sluggish on the climb and noisy on the descent (engine made some loud sounds as I cut the throttle enough to bring the Raptor back down after the climb test).

Any ideas on this?

I asked the Shop guy about running a tuned pipe and he said that there wouldn't be a problem (I noticed it said TUNED .30 PIPE after I had ordered it from the guy) :arggg: