Ignition timing
03-25-2010 | 08:28 AM
#1
Ignition timing
Need some advice. I have a new Turnigy/FTL 52cc engine. I have yet to run it but would like to know if there is available commercialy, a timing checker? I am used to a timing light etc for car engines but would like to know if there is a specialty timer on the market for RC gas engines.
If not, could some of you tell me how you are timing your engines and to what degree before top dead center.
Appreciate it
Glenn Williams
[email protected]
If not, could some of you tell me how you are timing your engines and to what degree before top dead center.
Appreciate it
Glenn Williams
[email protected]
03-25-2010 | 08:46 AM
#2
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From: The Villages, Florida NJ
RE: Ignition timing
I have one too, just haven't run it yet. I wrote this for another guy, but it will work for you to.
Get Pennzoil, run it at 32:1 all the time.
Do check the timing, here's my way:
The easy no math timing.
Cut a strip of paper 1/4" x 5".
Rap the paper around the prop drive, back by the crankcase where the magnet is. Overlap the paper then cut with a #11 blade cut though both layers of the paper.
Now you have a piece of paper the exact circumference of the prop drive.
Cut it in half, take one of the halves and cut that in half again, take that and cut it in half also. Now cut it so it's in 1/3 and 2/3 pieces.
The 2/3 piece is how much before TDC the engine should fire, (30*).
Now find TDC by removing the spark plug, then sticking something in the hole, a pencil works fine. Move the crankshaft until the piston. is at the top of the cylinder, you'll find that about 5* either side of the TDC it doesn't feel like the piston is moving. Wiggle the crank back and forth until you can find the center of this piston not moving zone, that's TDC.
Now with a marker make a line across the edge of the prop drive onto the crankcase, it doesn't matter where, just that it's easy to see.
Now turn the prop drive clockwise a distance equal to the 2/3 piece of paper.
Plug the ignition into a 4.8v battery, and turn it on.
Now with the two screws loosened move the sensor off the magnet until you hear the ignition pop.
Tighten the screws for the sensor down, then confirm that the timing is still set that 2/3 piece of paper before the TDC mark.
You may have to lengthen one of the grooves in the sensor mount to get the timing correct.
1.Start the engine, set the throttle so the engine is going 3500 rpm.
2.With the engine running I turn the "L" needle in, it is always the needle that is closest to the engine, when the engine speeds up to 4000 rpm I adjust the throttle to bring it back to 3500 rpm. You keep repeating this step until your engine doesn't speed up anymore when you turn the "L" needle in.
3.Turn the "L" needle out 3/16th of a turn.
4.Open the "H" needle 2 turns out, open the throttle all the way open. Now slowly turn the "H" needle in the engine will increase in rpms. Turn the needle about 1/16 at a time, when you get no more increase in rpm the "H" is set properly.
5.Set you idle speed with your throttle trims, it's best to take the idle stop screw completely out, you should have it so the idle is correct with the trim in the middle, and the low trim kills the engine.
6.With the engine running at the idle speed that you fly at you should now be able to snap the throttle open and the engine quickly speed up. If it just dies, turn the "L" needle out 1/16th of a turn, repeat this step until is quickly speeds up. If when you snap the throttle open it stumbles then speeds up turn the "L" needle in 1/16th of a turn until it cleanly and quickly speeds up.
7.Close the hole or notch up in the choke plate, I'll post a picture of what I mean, I do it with soldiering the hole close, some use glue or a bolt.
After you modify the choke plate the way to start the engine is:
a. Close choke completely.
b. Open throttle half way.
c. Flip engine with ignition on until the engine coughs.
d. Take choke fully off.
e. Set throttle just above idle, flip until it starts, usually 3 to 5 flips.
Get Pennzoil, run it at 32:1 all the time.
Do check the timing, here's my way:
The easy no math timing.
Cut a strip of paper 1/4" x 5".
Rap the paper around the prop drive, back by the crankcase where the magnet is. Overlap the paper then cut with a #11 blade cut though both layers of the paper.
Now you have a piece of paper the exact circumference of the prop drive.
Cut it in half, take one of the halves and cut that in half again, take that and cut it in half also. Now cut it so it's in 1/3 and 2/3 pieces.
The 2/3 piece is how much before TDC the engine should fire, (30*).
Now find TDC by removing the spark plug, then sticking something in the hole, a pencil works fine. Move the crankshaft until the piston. is at the top of the cylinder, you'll find that about 5* either side of the TDC it doesn't feel like the piston is moving. Wiggle the crank back and forth until you can find the center of this piston not moving zone, that's TDC.
Now with a marker make a line across the edge of the prop drive onto the crankcase, it doesn't matter where, just that it's easy to see.
Now turn the prop drive clockwise a distance equal to the 2/3 piece of paper.
Plug the ignition into a 4.8v battery, and turn it on.
Now with the two screws loosened move the sensor off the magnet until you hear the ignition pop.
Tighten the screws for the sensor down, then confirm that the timing is still set that 2/3 piece of paper before the TDC mark.
You may have to lengthen one of the grooves in the sensor mount to get the timing correct.
1.Start the engine, set the throttle so the engine is going 3500 rpm.
2.With the engine running I turn the "L" needle in, it is always the needle that is closest to the engine, when the engine speeds up to 4000 rpm I adjust the throttle to bring it back to 3500 rpm. You keep repeating this step until your engine doesn't speed up anymore when you turn the "L" needle in.
3.Turn the "L" needle out 3/16th of a turn.
4.Open the "H" needle 2 turns out, open the throttle all the way open. Now slowly turn the "H" needle in the engine will increase in rpms. Turn the needle about 1/16 at a time, when you get no more increase in rpm the "H" is set properly.
5.Set you idle speed with your throttle trims, it's best to take the idle stop screw completely out, you should have it so the idle is correct with the trim in the middle, and the low trim kills the engine.
6.With the engine running at the idle speed that you fly at you should now be able to snap the throttle open and the engine quickly speed up. If it just dies, turn the "L" needle out 1/16th of a turn, repeat this step until is quickly speeds up. If when you snap the throttle open it stumbles then speeds up turn the "L" needle in 1/16th of a turn until it cleanly and quickly speeds up.
7.Close the hole or notch up in the choke plate, I'll post a picture of what I mean, I do it with soldiering the hole close, some use glue or a bolt.
After you modify the choke plate the way to start the engine is:
a. Close choke completely.
b. Open throttle half way.
c. Flip engine with ignition on until the engine coughs.
d. Take choke fully off.
e. Set throttle just above idle, flip until it starts, usually 3 to 5 flips.
03-25-2010 | 09:00 AM
#4
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From: Salem,
OR
RE: Ignition timing
ORIGINAL: soarrich
I have one too, just haven't run it yet. I wrote this for another guy, but it will work for you to.
Get Pennzoil, run it at 32:1 all the time.
Do check the timing, here's my way:
The easy no math timing.
Cut a strip of paper 1/4'' x 5''.
Rap the paper around the prop drive, back by the crankcase where the magnet is. Overlap the paper then cut with a #11 blade cut though both layers of the paper.
Now you have a piece of paper the exact circumference of the prop drive.
Cut it in half, take one of the halves and cut that in half again, take that and cut it in half also. Now cut it so it's in 1/3 and 2/3 pieces.
The 2/3 piece is how much before TDC the engine should fire, (30*).
Now find TDC by removing the spark plug, then sticking something in the hole, a pencil works fine. Move the crankshaft until the piston. is at the top of the cylinder, you'll find that about 5* either side of the TDC it doesn't feel like the piston is moving. Wiggle the crank back and forth until you can find the center of this piston not moving zone, that's TDC.
Now with a marker make a line across the edge of the prop drive onto the crankcase, it doesn't matter where, just that it's easy to see.
Now turn the prop drive clockwise a distance equal to the 2/3 piece of paper.
Plug the ignition into a 4.8v battery, and turn it on.
Now with the two screws loosened move the sensor off the magnet until you hear the ignition pop.
Tighten the screws for the sensor down, then confirm that the timing is still set that 2/3 piece of paper before the TDC mark.
You may have to lengthen one of the grooves in the sensor mount to get the timing correct.
1.Start the engine, set the throttle so the engine is going 3500 rpm.
2.With the engine running I turn the ''L'' needle in, it is always the needle that is closest to the engine, when the engine speeds up to 4000 rpm I adjust the throttle to bring it back to 3500 rpm. You keep repeating this step until your engine doesn't speed up anymore when you turn the ''L'' needle in.
3.Turn the ''L'' needle out 3/16th of a turn.
4.Open the ''H'' needle 2 turns out, open the throttle all the way open. Now slowly turn the ''H'' needle in the engine will increase in rpms. Turn the needle about 1/16 at a time, when you get no more increase in rpm the ''H'' is set properly.
5.Set you idle speed with your throttle trims, it's best to take the idle stop screw completely out, you should have it so the idle is correct with the trim in the middle, and the low trim kills the engine.
6.With the engine running at the idle speed that you fly at you should now be able to snap the throttle open and the engine quickly speed up. If it just dies, turn the ''L'' needle out 1/16th of a turn, repeat this step until is quickly speeds up. If when you snap the throttle open it stumbles then speeds up turn the ''L'' needle in 1/16th of a turn until it cleanly and quickly speeds up.
7.Close the hole or notch up in the choke plate, I'll post a picture of what I mean, I do it with soldiering the hole close, some use glue or a bolt.
After you modify the choke plate the way to start the engine is:
a. Close choke completely.
b. Open throttle half way.
c. Flip engine with ignition on until the engine coughs.
d. Take choke fully off.
e. Set throttle just above idle, flip until it starts, usually 3 to 5 flips.
I have one too, just haven't run it yet. I wrote this for another guy, but it will work for you to.
Get Pennzoil, run it at 32:1 all the time.
Do check the timing, here's my way:
The easy no math timing.
Cut a strip of paper 1/4'' x 5''.
Rap the paper around the prop drive, back by the crankcase where the magnet is. Overlap the paper then cut with a #11 blade cut though both layers of the paper.
Now you have a piece of paper the exact circumference of the prop drive.
Cut it in half, take one of the halves and cut that in half again, take that and cut it in half also. Now cut it so it's in 1/3 and 2/3 pieces.
The 2/3 piece is how much before TDC the engine should fire, (30*).
Now find TDC by removing the spark plug, then sticking something in the hole, a pencil works fine. Move the crankshaft until the piston. is at the top of the cylinder, you'll find that about 5* either side of the TDC it doesn't feel like the piston is moving. Wiggle the crank back and forth until you can find the center of this piston not moving zone, that's TDC.
Now with a marker make a line across the edge of the prop drive onto the crankcase, it doesn't matter where, just that it's easy to see.
Now turn the prop drive clockwise a distance equal to the 2/3 piece of paper.
Plug the ignition into a 4.8v battery, and turn it on.
Now with the two screws loosened move the sensor off the magnet until you hear the ignition pop.
Tighten the screws for the sensor down, then confirm that the timing is still set that 2/3 piece of paper before the TDC mark.
You may have to lengthen one of the grooves in the sensor mount to get the timing correct.
1.Start the engine, set the throttle so the engine is going 3500 rpm.
2.With the engine running I turn the ''L'' needle in, it is always the needle that is closest to the engine, when the engine speeds up to 4000 rpm I adjust the throttle to bring it back to 3500 rpm. You keep repeating this step until your engine doesn't speed up anymore when you turn the ''L'' needle in.
3.Turn the ''L'' needle out 3/16th of a turn.
4.Open the ''H'' needle 2 turns out, open the throttle all the way open. Now slowly turn the ''H'' needle in the engine will increase in rpms. Turn the needle about 1/16 at a time, when you get no more increase in rpm the ''H'' is set properly.
5.Set you idle speed with your throttle trims, it's best to take the idle stop screw completely out, you should have it so the idle is correct with the trim in the middle, and the low trim kills the engine.
6.With the engine running at the idle speed that you fly at you should now be able to snap the throttle open and the engine quickly speed up. If it just dies, turn the ''L'' needle out 1/16th of a turn, repeat this step until is quickly speeds up. If when you snap the throttle open it stumbles then speeds up turn the ''L'' needle in 1/16th of a turn until it cleanly and quickly speeds up.
7.Close the hole or notch up in the choke plate, I'll post a picture of what I mean, I do it with soldiering the hole close, some use glue or a bolt.
After you modify the choke plate the way to start the engine is:
a. Close choke completely.
b. Open throttle half way.
c. Flip engine with ignition on until the engine coughs.
d. Take choke fully off.
e. Set throttle just above idle, flip until it starts, usually 3 to 5 flips.
you can't cut something in half and get 1/3... if you want to use the paper strip method, measure the length of the paper divide it by 360 and multiply by 30, or just print yourself off a degree wheel and have a piece ofcoat hanger as a indicator...
03-25-2010 | 09:30 AM
#5
My Feedback: (16)
RE: Ignition timing
To print out a degree wheel and mount it on a piece of plywood (Any kind) is so easy, I do not bother with folding and cutting up paper.
If you set timing on these every day, you eventually get to where you can eyeball it within a degree.
If you set timing on these every day, you eventually get to where you can eyeball it within a degree.
03-25-2010 | 10:04 AM
#6
Senior Member
My Feedback: (4)
RE: Ignition timing
Easiest method..
Take the plug wire off so you can hear the spark.
turn the crank (CCW) slowly..when you hear the spark make a pencil line across the hub and crankcase..
Measure hub diameter, multiply by .244 for 28 degreess...put piston on TDC..Marks should be that distance apart...
If it takes more than 5 minutes you're really slow...
Take the plug wire off so you can hear the spark.
turn the crank (CCW) slowly..when you hear the spark make a pencil line across the hub and crankcase..
Measure hub diameter, multiply by .244 for 28 degreess...put piston on TDC..Marks should be that distance apart...
If it takes more than 5 minutes you're really slow...
03-25-2010 | 11:18 AM
#9
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From: Beijing, CHINA
RE: Ignition timing
A easy way to verify the angle:
"By light of spark to verify the angle"
First,screw out the plug,make it eay to rotate the shaft,and drag the HT wire near the shaft,then turn off the lamp darken the entironment, rotate the shaft,make the HT spark onto the shaft.
you will see the firing angle pretty clearly.
"By light of spark to verify the angle"
First,screw out the plug,make it eay to rotate the shaft,and drag the HT wire near the shaft,then turn off the lamp darken the entironment, rotate the shaft,make the HT spark onto the shaft.
you will see the firing angle pretty clearly.
03-25-2010 | 11:31 AM
#10
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From: The Villages, Florida NJ
RE: Ignition timing
ORIGINAL: rangerfredbob
Your paper cutting method makes for 22.5*... 360/2=180 180/2=90 90/2=45 45/2=22.5
you can't cut something in half and get 1/3... if you want to use the paper strip method, measure the length of the paper divide it by 360 and multiply by 30, or just print yourself off a degree wheel and have a piece ofcoat hanger as a indicator...
Your paper cutting method makes for 22.5*... 360/2=180 180/2=90 90/2=45 45/2=22.5
you can't cut something in half and get 1/3... if you want to use the paper strip method, measure the length of the paper divide it by 360 and multiply by 30, or just print yourself off a degree wheel and have a piece ofcoat hanger as a indicator...
Quick and dirty set it so the spark is 3/8" BTDC you'll be very close on any engine I measured. I just do it by eye, the engines with 6 bolts shows you what 60* is, if you can't hit 30* within 1~2* by eye put the beer bottle down.
03-25-2010 | 04:41 PM
#12
RE: Ignition timing
Thanks guys. I really appreciate it. Cant wait to get back home and fire this engine up. By the way do any of you have the Turnigy 52cc? If so how does she run and what prop are you running?
You guys rock.
Glenn
You guys rock.
Glenn
03-25-2010 | 05:37 PM
#13
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From: The Villages, Florida NJ
RE: Ignition timing
ORIGINAL: willig10
By the way do any of you have the Turnigy 52cc? If so how does she run and what prop are you running?
By the way do any of you have the Turnigy 52cc? If so how does she run and what prop are you running?
I have one, but haven't run it yet. I also have a couple of Turnigy 26cc motors which are the smoothest gas motors I've ever run, not super powerful, but OK, if the 52 is as good as the 26 I will be very happy.
03-25-2010 | 07:20 PM
#14
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From: Gales Ferry, CT
RE: Ignition timing
http://www.ossmann.com/protractor/co...protractor.pdf Print this out and then enlarge by 150%. Tape it to a manilla folder in a couple places and cut through both to the shape of the protractor. Cheap and accurate.
Order a Rcexl hall sensor checker/timing checker from http://www.shop.kavarootusa.com/product.sc?productId=29. They also sell the plug in tach.
Get a cheap dial indicator with magnet base from your favorite place to find tdc and you will be able to accurately set the timing.
Order a Rcexl hall sensor checker/timing checker from http://www.shop.kavarootusa.com/product.sc?productId=29. They also sell the plug in tach.
Get a cheap dial indicator with magnet base from your favorite place to find tdc and you will be able to accurately set the timing.
03-26-2010 | 08:23 PM
#17
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From: Gales Ferry, CT
RE: Ignition timing
ORIGINAL: Antique
Easiest method..
Take the plug wire off so you can hear the spark.
You mean remove the plug from the cylinder and reinstall it in the cap don't you?
turn the crank (CCW) slowly..when you hear the spark make a pencil line across the hub and crankcase..
Measure hub diameter, multiply by .244 for 28 degreess...put piston on TDC.
How do you find TDC? Rock and guesstimate?.
Marks should be that distance apart...
If it takes more than 5 minutes you're really slow...
Easiest method..
Take the plug wire off so you can hear the spark.
You mean remove the plug from the cylinder and reinstall it in the cap don't you?
turn the crank (CCW) slowly..when you hear the spark make a pencil line across the hub and crankcase..
Measure hub diameter, multiply by .244 for 28 degreess...put piston on TDC.
How do you find TDC? Rock and guesstimate?.
Marks should be that distance apart...
If it takes more than 5 minutes you're really slow...
I like using a huge printed protractor so I can easily see the degrees and attach a pointer to the cylinder with a paper or spring clip. Also using a cheap-o dial indicator and magnetic base to find TDC is so easy. Set up the indicator, rotate the crank until the piston is at tdc and zero the indicator. Rotate the crank both ways until the indicator moves .001" and mark the protractor at both locations and divide in half to find exact tdc. measure over 28 degrees CCW from that point this is where you want the spark to fire or the rcexl to stop glowing and sounding. Adjust the sensor to make it so and tighten the screws. No guessing, no that should be close, it will be exact.
You can also use the indicator to check for crankshaft runout. You might be suprised to find out what's really making your plane shake so much.
CH ignitions came with good instructions.
03-26-2010 | 11:30 PM
#18
My Feedback: (6)
RE: Ignition timing
Here's one I made how I like them to be graduated. If you can't enlarge and print this one, let me know and I will e-mail you one. And by the way, you can't really find true TDC with a dial indicator without measuring to a certain value on each side of TDC and then splitting the difference, as mentioned above. The positive stop method is easier, and faster...
AV8TOR
AV8TOR
03-27-2010 | 01:56 AM
#19
Senior Member
RE: Ignition timing
O-My god,I did not no it was this complicated.
The more I am around people,the better I like my dog.
Grumpy No two.
The more I am around people,the better I like my dog.
Grumpy No two.
ORIGINAL: soarrich
I have one too, just haven't run it yet. I wrote this for another guy, but it will work for you to.
Get Pennzoil, run it at 32:1 all the time.
Do check the timing, here's my way:
The easy no math timing.
Cut a strip of paper 1/4'' x 5''.
Rap the paper around the prop drive, back by the crankcase where the magnet is. Overlap the paper then cut with a #11 blade cut though both layers of the paper.
Now you have a piece of paper the exact circumference of the prop drive.
Cut it in half, take one of the halves and cut that in half again, take that and cut it in half also. Now cut it so it's in 1/3 and 2/3 pieces.
The 2/3 piece is how much before TDC the engine should fire, (30*).
Now find TDC by removing the spark plug, then sticking something in the hole, a pencil works fine. Move the crankshaft until the piston. is at the top of the cylinder, you'll find that about 5* either side of the TDC it doesn't feel like the piston is moving. Wiggle the crank back and forth until you can find the center of this piston not moving zone, that's TDC.
Now with a marker make a line across the edge of the prop drive onto the crankcase, it doesn't matter where, just that it's easy to see.
Now turn the prop drive clockwise a distance equal to the 2/3 piece of paper.
Plug the ignition into a 4.8v battery, and turn it on.
Now with the two screws loosened move the sensor off the magnet until you hear the ignition pop.
Tighten the screws for the sensor down, then confirm that the timing is still set that 2/3 piece of paper before the TDC mark.
You may have to lengthen one of the grooves in the sensor mount to get the timing correct.
1.Start the engine, set the throttle so the engine is going 3500 rpm.
2.With the engine running I turn the ''L'' needle in, it is always the needle that is closest to the engine, when the engine speeds up to 4000 rpm I adjust the throttle to bring it back to 3500 rpm. You keep repeating this step until your engine doesn't speed up anymore when you turn the ''L'' needle in.
3.Turn the ''L'' needle out 3/16th of a turn.
4.Open the ''H'' needle 2 turns out, open the throttle all the way open. Now slowly turn the ''H'' needle in the engine will increase in rpms. Turn the needle about 1/16 at a time, when you get no more increase in rpm the ''H'' is set properly.
5.Set you idle speed with your throttle trims, it's best to take the idle stop screw completely out, you should have it so the idle is correct with the trim in the middle, and the low trim kills the engine.
6.With the engine running at the idle speed that you fly at you should now be able to snap the throttle open and the engine quickly speed up. If it just dies, turn the ''L'' needle out 1/16th of a turn, repeat this step until is quickly speeds up. If when you snap the throttle open it stumbles then speeds up turn the ''L'' needle in 1/16th of a turn until it cleanly and quickly speeds up.
7.Close the hole or notch up in the choke plate, I'll post a picture of what I mean, I do it with soldiering the hole close, some use glue or a bolt.
After you modify the choke plate the way to start the engine is:
a. Close choke completely.
b. Open throttle half way.
c. Flip engine with ignition on until the engine coughs.
d. Take choke fully off.
e. Set throttle just above idle, flip until it starts, usually 3 to 5 flips.
I have one too, just haven't run it yet. I wrote this for another guy, but it will work for you to.
Get Pennzoil, run it at 32:1 all the time.
Do check the timing, here's my way:
The easy no math timing.
Cut a strip of paper 1/4'' x 5''.
Rap the paper around the prop drive, back by the crankcase where the magnet is. Overlap the paper then cut with a #11 blade cut though both layers of the paper.
Now you have a piece of paper the exact circumference of the prop drive.
Cut it in half, take one of the halves and cut that in half again, take that and cut it in half also. Now cut it so it's in 1/3 and 2/3 pieces.
The 2/3 piece is how much before TDC the engine should fire, (30*).
Now find TDC by removing the spark plug, then sticking something in the hole, a pencil works fine. Move the crankshaft until the piston. is at the top of the cylinder, you'll find that about 5* either side of the TDC it doesn't feel like the piston is moving. Wiggle the crank back and forth until you can find the center of this piston not moving zone, that's TDC.
Now with a marker make a line across the edge of the prop drive onto the crankcase, it doesn't matter where, just that it's easy to see.
Now turn the prop drive clockwise a distance equal to the 2/3 piece of paper.
Plug the ignition into a 4.8v battery, and turn it on.
Now with the two screws loosened move the sensor off the magnet until you hear the ignition pop.
Tighten the screws for the sensor down, then confirm that the timing is still set that 2/3 piece of paper before the TDC mark.
You may have to lengthen one of the grooves in the sensor mount to get the timing correct.
1.Start the engine, set the throttle so the engine is going 3500 rpm.
2.With the engine running I turn the ''L'' needle in, it is always the needle that is closest to the engine, when the engine speeds up to 4000 rpm I adjust the throttle to bring it back to 3500 rpm. You keep repeating this step until your engine doesn't speed up anymore when you turn the ''L'' needle in.
3.Turn the ''L'' needle out 3/16th of a turn.
4.Open the ''H'' needle 2 turns out, open the throttle all the way open. Now slowly turn the ''H'' needle in the engine will increase in rpms. Turn the needle about 1/16 at a time, when you get no more increase in rpm the ''H'' is set properly.
5.Set you idle speed with your throttle trims, it's best to take the idle stop screw completely out, you should have it so the idle is correct with the trim in the middle, and the low trim kills the engine.
6.With the engine running at the idle speed that you fly at you should now be able to snap the throttle open and the engine quickly speed up. If it just dies, turn the ''L'' needle out 1/16th of a turn, repeat this step until is quickly speeds up. If when you snap the throttle open it stumbles then speeds up turn the ''L'' needle in 1/16th of a turn until it cleanly and quickly speeds up.
7.Close the hole or notch up in the choke plate, I'll post a picture of what I mean, I do it with soldiering the hole close, some use glue or a bolt.
After you modify the choke plate the way to start the engine is:
a. Close choke completely.
b. Open throttle half way.
c. Flip engine with ignition on until the engine coughs.
d. Take choke fully off.
e. Set throttle just above idle, flip until it starts, usually 3 to 5 flips.
03-27-2010 | 01:59 AM
#20
Senior Member
RE: Ignition timing
Received engine.Do you have any more rejects.
The more I am around people the better I like my dog & cat.
Grumpy
The more I am around people the better I like my dog & cat.
Grumpy
ORIGINAL: Antique
Easiest method..
Take the plug wire off so you can hear the spark.
turn the crank (CCW) slowly..when you hear the spark make a pencil line across the hub and crankcase..
Measure hub diameter, multiply by .244 for 28 degreess...put piston on TDC..Marks should be that distance apart...
If it takes more than 5 minutes you're really slow...
Easiest method..
Take the plug wire off so you can hear the spark.
turn the crank (CCW) slowly..when you hear the spark make a pencil line across the hub and crankcase..
Measure hub diameter, multiply by .244 for 28 degreess...put piston on TDC..Marks should be that distance apart...
If it takes more than 5 minutes you're really slow...
03-28-2010 | 11:41 AM
#22
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From: Sandy,
UT
RE: Ignition timing
Zippy....thanks for the link to see how it's done...very helpful
av8tor77...thanks for the wheel....got it printed.
Now I'm ready to try it out and see how close/off my engines are.
Is this a great hobby or what?
Steve
Foggy Minded Mountain Man
av8tor77...thanks for the wheel....got it printed.
Now I'm ready to try it out and see how close/off my engines are.
Is this a great hobby or what?
Steve
Foggy Minded Mountain Man
03-28-2010 | 12:53 PM
#23
My Feedback: (19)
RE: Ignition timing
ORIGINAL: PlaneKrazee
How do you find TDC? Rock and guesstimate?.
How do you find TDC? Rock and guesstimate?.
This method removes any stacked tolerances and piston dwell you would note at TDC trying to measure it with a dial indicator. It is extremely quick to do .... far easier than trying to describe it here in words. The "rock and guess method" is just about as accurate as a dial indicator for this application. The positive stop is dead nuts on every time.
03-28-2010 | 02:13 PM
#25
My Feedback: (16)
RE: Ignition timing
I made a piston stop from an old spark plug.
I put the plug in a vice and knocked the porcelain out of it with a hammer and drift.
I epoxied a dowel inside the plug body with a nominal length protruding on the electrode end.
It works with all my engines with that thread size plug.
I put the plug in a vice and knocked the porcelain out of it with a hammer and drift.
I epoxied a dowel inside the plug body with a nominal length protruding on the electrode end.
It works with all my engines with that thread size plug.
