RPM drop with a 914 above 100%

by Jacques De Jonghe in 912 / 914 Technical Questions 13 years ago

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Re: RPM drop with a 914 above 100%

by Charly » 12 years ago

Charly

7 35 122

No, just disconnect the fuelfeed line into the fuel pressure regulator to permit the fuelflow check. This gives you the chance to check, if you have enough fuel flow for the engine. (Check figure 73-3 in R914 maintenance manual)

Karl (Charly) Kistler
HB-YPL(RV12iS) / HB-YNB (Helicopter CH7)
karl@kistleronline.ch
www.kistleronline.ch
www.chaletferienfurna.ch

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Re: RPM drop with a 914 above 100%

by Charly » 12 years ago

Charly

7 35 122

To have a clue, what results you shoult have, see the following results on my r914:
Battery voltage 12.5V: 2.11 l/min (126l/h)
Battery 13.3V: 2.57 l/min (155 l/h);
The engine needs 0.55 l/min (33l/h)

Karl (Charly) Kistler
HB-YPL(RV12iS) / HB-YNB (Helicopter CH7)
karl@kistleronline.ch
www.kistleronline.ch
www.chaletferienfurna.ch

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Re: RPM drop with a 914 above 100%

by Roger Lee » 12 years ago

Roger Lee

131 5.38k 5.44k

Hi Carlos,

Once you eliminate a fuel delivery issue then it's time to think about electrical, sensors, turbo.

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

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Re: RPM drop with a 914 above 100%

by Carlos Chazarra » 12 years ago

Carlos Chazarra

0 8 0

Thanks to all,
Interesting.
A clue... Today I did again test at full power: when it was, as always, in the range of 4500 rpm, 34" map, it fails down to 4000. With all throttle ahead, and the problem arising with rpm, I cut suddenly magnetos and fuel pumps, in order to open carbs just in that position of breakdown.
Well, I open carbs hubs and I find
15 cc fuel right carb
29 cc fuel left carb

Useful info?

I know this is not a good procedure for engine, but I have to have a clue...

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Re: RPM drop with a 914 above 100%

by Charly » 12 years ago

Charly

7 35 122

This is a sign, that you have a fuel problem, perform the Fuelfllow check as imentioned above

Karl (Charly) Kistler
HB-YPL(RV12iS) / HB-YNB (Helicopter CH7)
karl@kistleronline.ch
www.kistleronline.ch
www.chaletferienfurna.ch

Report

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