JamesClarkIV
Active Member
I'm looking for help understanding my hot starting problem. I'll give as many details as I can here and respectfully solicit your thoughts and recommendations.
IO-360-M1B
Impulse coupled slick magneto on left side
Non impulse coupled magneto on right side
200 hours since new
Neither magneto was timed prior to first flight, used whatever I got from Vans/Lycoming with the new engine. None of the plug gaps were checked prior to first flight...chalk it up to ignorance on my part.
Around 50 hours, I learned how to time the magnetos externally and set each to 25 BTDC. Between 50 hours and 96 hours, I noticed that hot starting was progressively getting more difficult, cold starting more or less ok. At 96 hours, I checked the mag timing and found one to have advanced 4 degrees to 29 BTDC and one to have advanced 2 degrees to 27 BTDC (unfortunately i didn't think to record/see which drifted more: right or left). Neither appeared to be loose and I don't think they drifted in their "external" timing wrt the engine. Also, during this time I began the hunt to lower CHTs with better baffle seals, etc, striving for the never higher than 400 F. I retimed both mags externally by loosening the mounting stud nuts slightly and shifting the mags 2 and 4 degrees respectively to return both to 25 BTDC at the 96 hr mark. I also checked and gapped 8 spark plugs for the first time at the 96 hour mark. Many were > 0.022 so i decided to replace 4, and regap 4 to .016. immediately noticed lower CHTs and seemed to have slightly better hot starts, but not great.
At 135 hours (1st annual), I rechecked the magneto timing and found that they were both still at 25BTDC (no more "internal" drift). I also verified neither was in the magneto recall SN range. I see that if it drifts more than 4 degrees I should IRAN, but haven't done that yet. I had wired my two ignition switches to only allow the starter button to operate when left mag was on and right mag was off. After many hours of experimenting, I noted that after cranking a few turns and getting a few pops, I could flip on the right mag switch during cranking (which killed the starter) but sometimes caused the engine to start.
Now at 200 hours and springtime, my hot starts are getting darn near impossible without 15 seconds of cranking and 5 or 6 attempts. Using the crutch of flipping on the second mag when the engine coughs, doesn't seem to help much any more.
I've tried a variety of techniques that I have read about here for starting after a short < 1 hr lunch stop, but I'm convinced it is a weak ignition, not plugs, not mixture, not knobology technique during start. I don't have a purge valve and not too interested in the work to install one.
At this point, my hot starting issues are really dragging me down to the point of causing huge alternator charging loads after getting started, and excessive wear on the starter. I'm quite interested in getting a single EI to replace a mag as I think this may help my starting (#1 goal).
What am I doing wrong; what should I be exploring further?
Should I remove/open my mags and reset the e-gap? Can I learn this by reading or need someone to show me?
Should I remove one and go direct to EI?
Your thoughts are much appreciated.
IO-360-M1B
Impulse coupled slick magneto on left side
Non impulse coupled magneto on right side
200 hours since new
Neither magneto was timed prior to first flight, used whatever I got from Vans/Lycoming with the new engine. None of the plug gaps were checked prior to first flight...chalk it up to ignorance on my part.
Around 50 hours, I learned how to time the magnetos externally and set each to 25 BTDC. Between 50 hours and 96 hours, I noticed that hot starting was progressively getting more difficult, cold starting more or less ok. At 96 hours, I checked the mag timing and found one to have advanced 4 degrees to 29 BTDC and one to have advanced 2 degrees to 27 BTDC (unfortunately i didn't think to record/see which drifted more: right or left). Neither appeared to be loose and I don't think they drifted in their "external" timing wrt the engine. Also, during this time I began the hunt to lower CHTs with better baffle seals, etc, striving for the never higher than 400 F. I retimed both mags externally by loosening the mounting stud nuts slightly and shifting the mags 2 and 4 degrees respectively to return both to 25 BTDC at the 96 hr mark. I also checked and gapped 8 spark plugs for the first time at the 96 hour mark. Many were > 0.022 so i decided to replace 4, and regap 4 to .016. immediately noticed lower CHTs and seemed to have slightly better hot starts, but not great.
At 135 hours (1st annual), I rechecked the magneto timing and found that they were both still at 25BTDC (no more "internal" drift). I also verified neither was in the magneto recall SN range. I see that if it drifts more than 4 degrees I should IRAN, but haven't done that yet. I had wired my two ignition switches to only allow the starter button to operate when left mag was on and right mag was off. After many hours of experimenting, I noted that after cranking a few turns and getting a few pops, I could flip on the right mag switch during cranking (which killed the starter) but sometimes caused the engine to start.
Now at 200 hours and springtime, my hot starts are getting darn near impossible without 15 seconds of cranking and 5 or 6 attempts. Using the crutch of flipping on the second mag when the engine coughs, doesn't seem to help much any more.
I've tried a variety of techniques that I have read about here for starting after a short < 1 hr lunch stop, but I'm convinced it is a weak ignition, not plugs, not mixture, not knobology technique during start. I don't have a purge valve and not too interested in the work to install one.
At this point, my hot starting issues are really dragging me down to the point of causing huge alternator charging loads after getting started, and excessive wear on the starter. I'm quite interested in getting a single EI to replace a mag as I think this may help my starting (#1 goal).
What am I doing wrong; what should I be exploring further?
Should I remove/open my mags and reset the e-gap? Can I learn this by reading or need someone to show me?
Should I remove one and go direct to EI?
Your thoughts are much appreciated.
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