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Old 10-22-2019, 05:57 PM
  #42976  
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Originally Posted by Hobbsy
Interestingly, the factory has the timing at 40 degrees btdc. When I first put my degree wheel on there I thought it had slipped. I'll look in the exhaust port tomorrow and see if the bronze goes all the way down to the seat.
Dave, was the spark at 40° btdc happening as the magnet entered the hall sensor or as the magnet was leaving the hall sensor? Some of the rcexel cdi units would spark at both points. Ignition timing should be checked for spark as the magnet leaves the hall sensor. It should be somewhere between 28-32° initial advance.

Last edited by Glowgeek; 10-22-2019 at 06:02 PM.
Old 10-22-2019, 06:49 PM
  #42977  
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Retarded timing also increases valve temperature and burning.

I learned that at age 15. Used money earned from moving block, brick, mortar and scaffolding to buy a badly banged up 1931 Ford. Drove it around the backroads for a couple weeks with the timing retarded.

Burned nasty pie shaped wedges out of the exhaust valves. Since I was too "smart" to ask Dad for operating info, he just let me learn the hard way. I was amazed to see how much he knew when he helped do the valve job. I asked a lot of questions from them on
Old 10-22-2019, 07:12 PM
  #42978  
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Well picked up this little gem today not to change the subject,
but this old senior was up for sale by an even old retired Veteran. He flew navel sea and rescue planes.
He could never get the hang of fly rc. I have heard of this quite often. It’s harder for a pilot to fly RC. Then it is for a RC pilot to fly a real plane. Something to do with there butt.
Anyway throw

some dollars at the old boy and brought home this lovely specimen it has a Saito 45 and an old conquest six channel Futaba radio on a.m. after new battery’s it actually still works. The engine normal gummed up a little heat and oil and then some fuel and it turns over and has compression. Yay per the old boys request he would like to see it fly. Plan is this weekend to video it and show him the flight.
Old 10-22-2019, 07:27 PM
  #42979  
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Yup and before you say those are 40 stickers. Yup sometimes I look at something but don’t see .
It is a 40, cool I don’t have one like that.
Old 10-22-2019, 11:17 PM
  #42980  
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Originally Posted by Hobbsy
Hey Pete, after how man beers does that happen?

I kinda blew yesterday and played all day, all engines are off planes for annuals. I may put different engines on some just to put time on the others. For example, the FG 11 will go where the 62 was on the black and white LT 40.
Well dave i'm sure most of us remember younger days when you went bar hopping on a friday or saturday night. After a few beers, when the beer goggles were in place, everybody including yourself looked and sounded a whole lot better, although sometimes you and the female got a big fright when you woke up in the morning but happily that's not the case with the fa115 and beer goggles don't work on an fa125. Sold my fa62 years ago when i changed up to fa82's for the 46 size decathlons.

Well you guys have been basking in a long hot summer which is coming to an end and ours is just about to start, we have the best weather here if you like temperate climates, they don't sell any snowplows.
Old 10-23-2019, 02:41 AM
  #42981  
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Originally Posted by Jesse Open
Retarded timing also increases valve temperature and burning.

I learned that at age 15. Used money earned from moving block, brick, mortar and scaffolding to buy a badly banged up 1931 Ford. Drove it around the backroads for a couple weeks with the timing retarded.

Burned nasty pie shaped wedges out of the exhaust valves. Since I was too "smart" to ask Dad for operating info, he just let me learn the hard way. I was amazed to see how much he knew when he helped do the valve job. I asked a lot of questions from them on
Yep, I've eaten valve pie myself retarding the timing too far. I've also mangled more than a few heads trying to port them.

Most cdi systems sold today are programmed to advance the timing based on monitored rpm. 28-32° initial allows for easier starting eg reduced kick back, thrown props and hacked up fingers. I'm not familiar with how Saito spec'd their cdi units so I'm just assuming it's similar to other gassers where electronic advance is initiated at 300+ rpm.

Last edited by Glowgeek; 10-23-2019 at 02:44 AM.
Old 10-23-2019, 03:00 AM
  #42982  
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Lonnie, it fires when the magnet is leaving the Hall effect sensor, I never saw one that fired approaching the sensor, that would really botch things up. Saito calls that a "medium' setting. I could move it either way but it does not kick back and it runs so nice. CH Ignitions retard to approximately 6 degrees btc at flipping speed, about 400 rpm. I will attach the degree wheel and demonstrate.

PS, I use the 7.2 volt CHI on the FG 11, it makes a spark that has an audible snap.

Last edited by Hobbsy; 10-23-2019 at 03:04 AM.
Old 10-23-2019, 03:02 AM
  #42983  
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Originally Posted by Rudolph Hart
Well dave i'm sure most of us remember younger days when you went bar hopping on a friday or saturday night. After a few beers, when the beer goggles were in place, everybody including yourself looked and sounded a whole lot better, although sometimes you and the female got a big fright when you woke up in the morning but happily that's not the case with the fa115 and beer goggles don't work on an fa125. Sold my fa62 years ago when i changed up to fa82's for the 46 size decathlons.

Well you guys have been basking in a long hot summer which is coming to an end and ours is just about to start, we have the best weather here if you like temperate climates, they don't sell any snowplows.

Pete, of course the 1.15 is beautiful, it's a Saito, you know the one about the girls all get prettier at closing time. That might apply to Saitos also.
Old 10-23-2019, 03:12 AM
  #42984  
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Originally Posted by Hobbsy
Lonnie, it fires when the magnet is leaving the Hall effect sensor, I never saw one that fired approaching the sensor, that would really botch things up. Saito calls that a "medium' setting. I could move it either way but it does not kick back and it runs so nice. CH Ignitions retard to approximately 6 degrees btc at flipping speed, about 400 rpm. I will attach the degree wheel and demonstrate.
Good to hear it's firing as the magnet leaves the sensor. 40° initial sounds high to me but I only have experience with 2 stroke gassers

I'm curious how that module retards 6° for startup. Maybe it's using the signal as the magnet enters the sensor combined with >400 rpm to make that happen. When you test the timing next time maybe try to make sure the magnet passes by the entire sensor to see if that's whats happening? Maybe you'll see 34° that way.
Old 10-23-2019, 03:18 AM
  #42985  
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It would have to be past it in order for the magnetic field to collapse through the sensor and send a signal.
Old 10-23-2019, 03:22 AM
  #42986  
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Originally Posted by Hobbsy
It would have to be past it in order for the magnetic field to collapse through the sensor and send a signal.
I don't explain things well on paper. Each time you degree the spark roll the engine all the way around so the cdi can detect the magnet entering and leaving the sensor twice. That way it can pick up an rpm reading. Or maybe just jiggle it back and forth.

Last edited by Glowgeek; 10-23-2019 at 03:27 AM.
Old 10-23-2019, 03:28 AM
  #42987  
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Do you know what I like ?
It works. How?
You two are sure giving a lot of good information Especially for diagnostics.

Did you see my barn find? Lol
Old 10-23-2019, 03:57 AM
  #42988  
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Hey were did you guys go I was only giving a bad time.
What I find crazy is how the 182 ignition has two different magnetic polarity and the ignition is smart enough to know which Cylinder is supposed to fire.
Old 10-23-2019, 03:57 AM
  #42989  
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The unit on the right has the Synchro Spark unit in line with the sensor, soon after they were built into the module. They retarded the timing to 6 degrees btc when set at 28 btc, they went to full advance by 2,500 but some for larger engines were all in at 1,500.
Great find indeed, I like to know how things work as well as the next guy, the 28 to 32 rule is obviously a little out dated, if the Saito engineers chose 40 degrees advance, they did so for a reason. I know it sure works well.
CHI retards the timing by 24 degrees at flipping speed, I don't know what the Saito unit does in that regard. So, when I run the CHI unit the Saito FG 11 would be firing at 16 degrees btc at flip. It does not kick back so that is a good setting.
Old 10-23-2019, 03:58 AM
  #42990  
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Dave, just checked the CH timing setup for gas conversion for saito 120-180. It says initial timing should be set to 30° btdc.
Old 10-23-2019, 04:02 AM
  #42991  
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As you can see, I've had this one for a long time, it lived on a Maloney 1.25.
Old 10-23-2019, 04:05 AM
  #42992  
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Boy I hope the old mechanical advanced I have works OK I’m toying with the idea of upgrading it to the new version
cost is an issue with that
Old 10-23-2019, 04:07 AM
  #42993  
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Also do you lose that much when running gas. Or is it negligible. After all are planes are so overpowered now.
Old 10-23-2019, 04:09 AM
  #42994  
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I think it's just semanics Dave. I can't fathom how a cdi would "retard" timing from the intial setup. All my 2 stroke gassers are set up with initial between 30-32° btdc and the cdi advances the timing from there based on increasing rpm. That's with cdi units labeled CH and RCexl.

Your right about Saito, they know what they're doing.
Old 10-23-2019, 04:14 AM
  #42995  
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Would there be a sensor built into the ignition module to detect RPMs so that it knows when the engine is running to advance the timing
Old 10-23-2019, 04:14 AM
  #42996  
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The word "retard" is used because that is the result, the ECM, if we can call it that, pauses each trigger pulse at low rpm so the result is the same as Mike's mechanical set up.
Old 10-23-2019, 04:18 AM
  #42997  
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Also here’s some food for thought if it fires after the magnet leaves the sensor that technically means that if you set the sensor at 32° before top dead center it’s actually firing at 28° before TDC
Old 10-23-2019, 04:24 AM
  #42998  
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Originally Posted by Hobbsy
The word "retard" is used because that is the result, the ECM, if we can call it that, pauses each trigger pulse at low rpm so the result is the same as Mike's mechanical set up.
OK, I'm lost. When we set the intial timing aren't we already at low rpm? Seems to me the unit can only advance from there.

Crunchy, yes the cdi units detect rpm and advance timing accordingly. The 3 wire hall effect sensors have 3 wires and a tach can be connected to monitor rpm.

Last edited by Glowgeek; 10-23-2019 at 04:30 AM.
Old 10-23-2019, 04:26 AM
  #42999  
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Yes that is correct the magic of the box takes over detects the RPM increase and automatically advances the timing
Old 10-23-2019, 04:32 AM
  #43000  
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A steel control rod is firmly jammed between the center cooling fins to serve as a pointer

This is where I have my high compression 1.50 set to fire, the spark actually occurs right where the degree wheel sits. I tried to use Dan;s suggested 35 degrees btc but with 11.24 to 1 compression it was mighty rattly sounding. I use a Sullivan black fuel bulb and glow plug with a hole drilled through the post to hold it at tdc while I set the trigger wheel.

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