GAS ENGINES
02-02-2010 | 11:05 PM
#2
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From: Port MacquarieNew South Wales, AUSTRALIA
RE: GAS ENGINES
Hi,
It sounds like the timing is too retarded. Try advancing the timing a little at a time until it consistently runs in the correct direction, unless you want to cause consternation in the pits by reversing out to the flight line
.
Cheers,
Colin
It sounds like the timing is too retarded. Try advancing the timing a little at a time until it consistently runs in the correct direction, unless you want to cause consternation in the pits by reversing out to the flight line
.Cheers,
Colin
02-02-2010 | 11:14 PM
#3
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From: OZark,
MO
RE: GAS ENGINES
ORIGINAL: Crash Campbell
Hi,
It sounds like the timing is too retarded. Try advancing the timing a little at a time until it consistently runs in the correct direction, unless you want to cause consternation in the pits by reversing out to the flight line.
Cheers,
Colin
Hi,
It sounds like the timing is too retarded. Try advancing the timing a little at a time until it consistently runs in the correct direction, unless you want to cause consternation in the pits by reversing out to the flight line
.Cheers,
Colin
02-03-2010 | 02:38 PM
#7
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From: Port MacquarieNew South Wales, AUSTRALIA
RE: GAS ENGINES
ORIGINAL: Crash Campbell
Hi,
It sounds like the timing is too retarded. Try advancing the timing a little at a time until it consistently runs in the correct direction, unless you want to cause consternation in the pits by reversing out to the flight line.
Cheers,
Colin
Hi,
It sounds like the timing is too retarded. Try advancing the timing a little at a time until it consistently runs in the correct direction, unless you want to cause consternation in the pits by reversing out to the flight line
.Cheers,
Colin
Like I said, advance the timing.
Cheers,
Colin
02-03-2010 | 08:41 PM
#8
RE: GAS ENGINES
I believe the problem would be the opposite. if it is too advanced, it is firing too far before TDC, so it runs backward, but if you retard it, it should really fire the engine as it is passing TDC, I would say retard the timing.
Curtis
Curtis
02-03-2010 | 09:37 PM
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From: Port MacquarieNew South Wales, AUSTRALIA
RE: GAS ENGINES
ORIGINAL: beau0090_99
I believe the problem would be the opposite. if it is too advanced, it is firing too far before TDC, so it runs backward, but if you retard it, it should really fire the engine as it is passing TDC, I would say retard the timing.
Curtis
I believe the problem would be the opposite. if it is too advanced, it is firing too far before TDC, so it runs backward, but if you retard it, it should really fire the engine as it is passing TDC, I would say retard the timing.
Curtis
The above quote is not correct
If you retard the timing you increase the torque at low revs. If the timing is too retarded the motor will start and run backwards. In the holocene epoc I had a Montessa Coata Trials bike, if I retarded the spark to max low down grunt and went too far it would start backwards. The hole may still be in the neighbours garage to proove this statement.
Cheers,
Colin
02-04-2010 | 10:14 AM
#10
RE: GAS ENGINES
ORIGINAL: Crash Campbell
Hi,
The above quote is not correct
If you retard the timing you increase the torque at low revs. If the timing is too retarded the motor will start and run backwards. In the holocene epoc I had a Montessa Coata Trials bike, if I retarded the spark to max low down grunt and went too far it would start backwards. The hole may still be in the neighbours garage to proove this statement.
Cheers,
Colin
ORIGINAL: beau0090_99
I believe the problem would be the opposite. if it is too advanced, it is firing too far before TDC, so it runs backward, but if you retard it, it should really fire the engine as it is passing TDC, I would say retard the timing.
Curtis
I believe the problem would be the opposite. if it is too advanced, it is firing too far before TDC, so it runs backward, but if you retard it, it should really fire the engine as it is passing TDC, I would say retard the timing.
Curtis
The above quote is not correct
If you retard the timing you increase the torque at low revs. If the timing is too retarded the motor will start and run backwards. In the holocene epoc I had a Montessa Coata Trials bike, if I retarded the spark to max low down grunt and went too far it would start backwards. The hole may still be in the neighbours garage to proove this statement.
Cheers,
Colin
02-04-2010 | 02:01 PM
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From: FrederickMD
RE: GAS ENGINES
Retarding the timing DOES increase low end torque, but only because the cylinder is firing closer to TDC and the burn is starting closer to maximum compression. This robs high end torque because the burn doesn't get a chance to finish before the exhaust stroke starts. Consequently, as RPM increases, it is desirable to advance the spark timing (spark occurs earlier in the cycle).
If you advance the spark to far, the ignition occurs too early, and the momentum of the engine is insufficient to carry the piston through TDC, and will run BACKWARDS. Once the engine starts backwards, now the timing is VERY RETARDED in relation to the engine motion - that is the ignition spark occurs well after the piston goes through TDC, so it won't turn itself around.
I agree that the timing should be checked, and retarded (delayed) by adjusting the Halls sensor. Seems that 23 Degrees BTDC is a favorite value to start with on our airplane engines.
Brad
If you advance the spark to far, the ignition occurs too early, and the momentum of the engine is insufficient to carry the piston through TDC, and will run BACKWARDS. Once the engine starts backwards, now the timing is VERY RETARDED in relation to the engine motion - that is the ignition spark occurs well after the piston goes through TDC, so it won't turn itself around.
I agree that the timing should be checked, and retarded (delayed) by adjusting the Halls sensor. Seems that 23 Degrees BTDC is a favorite value to start with on our airplane engines.
Brad
