I assume you mounted a switch for the servo motor on your panel. It's purpos
e is to break the circuit of the servo motor for a short time in case of sur
ging of the TCU. Maybe this is your problem? Run the engine and then briefly
switch servo switch off and back on. Hopefully it's that simple. It is supp
ose to stabilize the surging.
Jerry
Sent from my iPad
On May 16, 2012, at 3:36 PM, Robert Borger <rlborger@mac.com> wrote:
> 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 en
gine 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 co
mmitments (preparing for a 2 week trip to SC). Monday, I went out to do a f
ull run-up and check of the engine. Started fine, idled OK as long as I hel
d the "Choke" out while warming up. After it was warm it idled OK without t
he "Choke." Engine nice and smooth. I slowly applied throttle and as it ap
proached 4000 RPM it began to surge. Engine RPM dropped to about 3250 and w
ould return to almost 4000 then drop down to 3250 and return to almost 4000,
repeat, repeat, down/up/down/up/down 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 almo
st equal. The lower plugs always have had a 50-75 RPM greater drop. Turnin
g on the boost pump made no difference. Engine has about 25 hrs total time s
o 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 che
ck? Could it be the Turbo or Turbo Controller?
>
> For starters, I guess I need someone to help operate the throttle while I o
bserve the turbo controller and wastegate operation. Tommy will probably he
lp 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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