Friends,
As many of you know, my Europa has been down for about a year while it
was converted it to tri-gear and I rebuilt the instrument panel. We ran
the engine about 2 weeks ago to check the carb balance and idle. Those
were OK at the time. I didn't run the engine any further that day
because of other commitments (preparing for a 2 week trip to SC).
Monday, I went out to do a full run-up and check of the engine. Started
fine, idled OK as long as I held the "Choke" out while warming up.
After it was warm it idled OK without the "Choke." Engine nice and
smooth. I slowly applied throttle and as it approached 4000 RPM it
began to surge. Engine RPM dropped to about 3250 and would return to
almost 4000 then drop down to 3250 and return to almost 4000, repeat,
repeat, down/up/down/up/down=85 Below 3950 RPM it ran smooth and fine.
Advance the throttle and it began to surge.
EGTs & CHTs all normal and close to equal. Mag drop at 3900 RPM were
almost equal. The lower plugs always have had a 50-75 RPM greater drop.
Turning on the boost pump made no difference. Engine has about 25 hrs
total time so far and has run like a sewing machine up to now.
Any ideas as to the source of the problem? Any suggestions as what to
check? Could it be the Turbo or Turbo Controller?
For starters, I guess I need someone to help operate the throttle while
I observe the turbo controller and wastegate operation. Tommy will
probably help there.
Any input would be appreciated.
Thanks in advance!
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop.
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger@mac.com
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