Can someone please let me know if the 570 sparks every revolution or every other revolution?
Trying to sort out the tach pickup for the Vapor.
Many tks.
Steve
Trying to sort out the tach pickup for the Vapor.
Many tks.
Steve
FE570 - Spark every revolution??
- Thread starter sgomes
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Joined Jun 2007
4K Posts | 1K+
south east WA Australia
the pulse coil is fitted to the crank so it sparks every revolution
"lost spark setup"
for it to only spark every second revolution there has to be a position sensor on the camshaft
try another tach that is known to work and see what it says.. there may be some noise in the system confusing the tach unit
"lost spark setup"
for it to only spark every second revolution there has to be a position sensor on the camshaft
try another tach that is known to work and see what it says.. there may be some noise in the system confusing the tach unit
As far as I know most modern single cylinder bikes have a "spare spark" setup.
And then....I might be totally wrong....
M.
And then....I might be totally wrong....
M.
You're not wrong about how four-strokes work, however it is simpler mechanically/electronically to have the sparkplug spark every revolution. It doesn't do anything but spark in a cylinder that is evacuating exhaust gasses however.
Joined Apr 2014
689 Posts | 252+
Chilliwack, BC, Canada
FWIW
I question this?? On exhaust there can be a after-burn as not all gases burn off during the first fire. The Dodge hemi is one example on two plugs per cylinder that fire in different time to create a pre and after burn. What would the result be if the exhaust gases ignited on the exhaust stroke? The other question of double fire would make me curious about wear on the electrode, Premature spark plug gap failure?
I would be curious to see a modern four stroke engine fire twice as I have only ever have seen a single fire during one complete four stoke cycle. I think all kinds of issues could happen as electronics map the spark fire to ensure no misfire as well a ton of other things such as revolutions per min. Cam, Crank and other sensors take note and send the signal to fire at only at the time it is required.
I however am not sure on this specific model but would think a cam sensor of some sort only allows it to fire once no matter what the crank does.
Joined Nov 2012
2K Posts | 821+
Iceland
To answer it with a question: What sensor in a Husaberg motor allows the engine to only fire on the compression cycle?
(Just to be clear: There is none!)
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Sparks at TDC of exhaust stroke so cylinder is nearly empty of uncompressed exhaust. Not much left to happen. Not the same situation as the hemi.
Joined Nov 2012
2K Posts | 821+
Iceland
Thinking like a fool, Waste spark system same as what my V twin had. Thanks everyone for the wake up
It's certainly allowed to think and question
I've set up a few different engines all using "wasted spark" which Fires the Spark Plug every time the Piston is at Top Dead Centre. Like previously said:
The 570 doesn't have a Cam Sensor only a crank sensor, so the Ignition system doesn't know if the Piston is at the Top Dead Centre for Compression Stroke or Top Dead Centre for Exhaust Stroke.
You also see many multi cylinder engines with 2 Spark Plug Leads coming out of the 1 Coil. They both fire at the same time but 1 Piston is TDC Compression stroke and the other is TDC Exhaust Stroke.
The 570 doesn't have a Cam Sensor only a crank sensor, so the Ignition system doesn't know if the Piston is at the Top Dead Centre for Compression Stroke or Top Dead Centre for Exhaust Stroke.
You also see many multi cylinder engines with 2 Spark Plug Leads coming out of the 1 Coil. They both fire at the same time but 1 Piston is TDC Compression stroke and the other is TDC Exhaust Stroke.
Ok, I go along with the above, that the 570, as well as most other single cylinder bikes, spark off the crank every revolution. When installing the tach sensor, I tried both the two conductor sensor wire (which is the same as the power lead), connecting the red wire to the coil input and the black to a good ground; as well as the single conductor red wire lead wrapped around the plug wire several times.
According to the instructions, I programmed in 1 ppr (pulses per revolution), only to find that both configurations gave me an idle of around 760 rpm, or about half what I expected.
Then I contacted TT tech support, and was immediately told to change to .5 ppr, and to use only the single conductor red wire wrapped around the plug wire. Indeed, my tach now seems to be right on. It seems to me the confusion (there's lots of it!!) might have been avoided had TT used rpp - revs per pulse. Then users, 2T or 4T, could program 1 rpp, and those 4T bikes not employing wasted spark, would simply program 2 rpp.
Also, I can state with certainty that the tach is correct, because I verified it using Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator, an incredible tool for selecting gearing that will yield desirable speed/rpm ratios.
Many times I have read posts from dirt bikers stating they have no use for a tach. But, it seems to me that knowing when your bikes torque and power come in would be useful information.
I confirmed several of my bike's speed/rpm readings against GearingCommander numbers, and they were all within 100 rpm.
I'm very pleased with the Vapor, esp considering its price point.
Hope this helps.
According to the instructions, I programmed in 1 ppr (pulses per revolution), only to find that both configurations gave me an idle of around 760 rpm, or about half what I expected.
Then I contacted TT tech support, and was immediately told to change to .5 ppr, and to use only the single conductor red wire wrapped around the plug wire. Indeed, my tach now seems to be right on. It seems to me the confusion (there's lots of it!!) might have been avoided had TT used rpp - revs per pulse. Then users, 2T or 4T, could program 1 rpp, and those 4T bikes not employing wasted spark, would simply program 2 rpp.
Also, I can state with certainty that the tach is correct, because I verified it using Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator, an incredible tool for selecting gearing that will yield desirable speed/rpm ratios.
Many times I have read posts from dirt bikers stating they have no use for a tach. But, it seems to me that knowing when your bikes torque and power come in would be useful information.
I confirmed several of my bike's speed/rpm readings against GearingCommander numbers, and they were all within 100 rpm.
I'm very pleased with the Vapor, esp considering its price point.
Hope this helps.
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