RE: SK 90-----WOW
Finally, I was able to get some time to work on the engine at home. I fully opened the throtle and opened the LS needle until I saw a gap of about 1/64 in the needle. Then, I removed the plug I had on one of the pitts outlets. With the dremell, I made some cuts to the outlets to be able to close them and reduce their area about one half. I also removed some material from the cowl over the engine head. (sorry, I could not upload any pictures, don't know why it would not let me).
Temp @ 68-F, prop TF 15x6, fuel 5% Omega.
I put 5% Omega fuel, primmed the engine, put the igniter, and it started on one flip against compression. Rapidly I opened the throttle to get stable RPMs. Then, I opened full throttle and adjusted HS needle. I was able to go rich from 7K+ to 6K+ in one turn of the HSN. I also had big smoke at the exhaust. I then adjusted the RPMs to about 7000. I throttle up and down for a while. Checked the engine temp after five minutes of WOT and I measured 245-F. Let the 12-Oz tank go empty.
After 20-mins break, I put another tank and went for pick RPMs. I got a max of 8400 RPMs. Then, I back out 1/4 of turn of HSN and got 8100 RPM. I checked temp after five minutes of WOT and got 295-F. Put the plane at 90-degrees vertical and the RPMs increased to 8200 and consistent for about one minute. Then, I checked idle. I open throttle to get around 2400-2500 RPMs. Then, tested at 30-sec, one-minute, and two-minute idle transition to WOT. in 30-sec I got just a bit of load-up. At 2-mins, I got just a small hick-up. This time, the color of the oil at the exhaust gases is clear. No more gray oil like at the beginning.
From WOT throttle to idle, the engine goes to about 3000 RPM and slowly goes down to 2400 RPM. Is this a sign of being a bit rich?
So, I believe I am ready for flying again. I hope I can go to the field tomorrow afternoon.
What do you think about this runs?
Do you think that I still need to open LSN a bit more?
Thanks in advance for your input.
Pedro
edited for uploading pics. Didn't work.[:@]