wjb
Well Known Member
UPDATE: was able to do a A/B check with a mag from a friend who just pulled it to install a SureFly .. worked perfectly! I'm going to send in out for IRAN and we'll see what was wrong.
I've run into a engine starting issue that I would like your advice on:
I no longer can start the engine on my L mag; I might get a bit of ignition, but it doesn't persist, and pushing in the mixture didn't start the engine.
Flooded start protocol (throttle full open, mix out, crank till catch and then quickly adjust mix and throttle) did not improve the situation (ie, not just a flooded engine)
It now won't start on the L mag alone. Crank the battery into the grave; no workie.
Observation: while cranking for start, occasionally a mini catch would occur ... I found if I flip on the right mag then, it would catch and start Engine coughs, starts and settles in (my engine always takes a few seconds to get to a nice, purring ops state).
Mag check at 2000 rpm shows the typical 100-110 RPM drop L and R.
Just completed my annual condition inspection. Other than checking timing and cleaning/gapping the plugs, nothing was done with the mags.
Any thoughts on the cause from the VAF brain trust? Is my L mag hosed?
TL;DR content:
- Lyc IO-360-M1B, 370h, Dual conventional Slick mags, impulse on left.
- recent compression check in the high 70's on all cylinders
- borescope looks super clean (thanks LOP!)
- air filter is clean
- air ducts to the servo are intact, secure, clean inside and out.
- Fuel pressure good on engine pump and boost pump
- Injectors clean
- Fuel flow test to each of the flow divider arms are balanced.
- Plugs new-ish (<50h), cleaned, resistance checked (< 1kohm), and gapped,
- Timing looks good at 25-26 deg both mags.
- 1T, 3T, 2B, 4B show sparks in that order when the impulse coupler snaps.
- P leads appear sound; no sound from buzz box when mags are off (shorted) during timing checks
Normal starting process:
I have individual toggle switches for each mag; set up to only allow the starter to run when L mag is on, R mag is off, and starter button pressed.
I've run into a engine starting issue that I would like your advice on:
I no longer can start the engine on my L mag; I might get a bit of ignition, but it doesn't persist, and pushing in the mixture didn't start the engine.
Flooded start protocol (throttle full open, mix out, crank till catch and then quickly adjust mix and throttle) did not improve the situation (ie, not just a flooded engine)
It now won't start on the L mag alone. Crank the battery into the grave; no workie.
Observation: while cranking for start, occasionally a mini catch would occur ... I found if I flip on the right mag then, it would catch and start Engine coughs, starts and settles in (my engine always takes a few seconds to get to a nice, purring ops state).
Mag check at 2000 rpm shows the typical 100-110 RPM drop L and R.
Just completed my annual condition inspection. Other than checking timing and cleaning/gapping the plugs, nothing was done with the mags.
Any thoughts on the cause from the VAF brain trust? Is my L mag hosed?
TL;DR content:
- Lyc IO-360-M1B, 370h, Dual conventional Slick mags, impulse on left.
- recent compression check in the high 70's on all cylinders
- borescope looks super clean (thanks LOP!)
- air filter is clean
- air ducts to the servo are intact, secure, clean inside and out.
- Fuel pressure good on engine pump and boost pump
- Injectors clean
- Fuel flow test to each of the flow divider arms are balanced.
- Plugs new-ish (<50h), cleaned, resistance checked (< 1kohm), and gapped,
- Timing looks good at 25-26 deg both mags.
- 1T, 3T, 2B, 4B show sparks in that order when the impulse coupler snaps.
- P leads appear sound; no sound from buzz box when mags are off (shorted) during timing checks
Normal starting process:
I have individual toggle switches for each mag; set up to only allow the starter to run when L mag is on, R mag is off, and starter button pressed.
- 5 sec prime with pump on, mix and throttle in
- mix to ICO,
- throttle cracked
- pump off
- engage starter
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