Hi,

I was wondering if you could give me some advice and help with my JJ1400 engine. I just got the rotor assembly back from being dynamically balanced at RTI, and I made all modifications described in post number 608 of this thread. I also sealed up the front case seam and rear tail cone seam with a high temp copper silicon. When it was run without being sealed up, there were excessive blue flames coming out the back, and a jet of air coming from the front seam of the outer case. It was too much to ignore.
So, I just got done running it with it being all sealed up, and at the lower rpm's the engine experiences a rpm drop of about 1,000 rpm just about every 4 - 5 seconds. I am sure that it is not the fuel pump because pump power is constant and doesn't fluctuate with the rpm drop. Temps are very good at about 520 C at idle. I am just trying to figure out what is causing the rpm drop. It doesn't experience the drop at high throttle positions. When I say higher, I mean from about 20% all the way up to 100% power. Do you know what might be the problem??? Maybe I should just ignore it and go flying?! It would make me feel a lot better if I knew what was causing the rpm drop.

Thanks for you time,
Brandon