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Misc: Ignition Optimum Kickstart Ignition Advance


Cyborg

Well Known and Active Website User
VOC Member
Getting off topic, but I took my M/C test on a DBD34 with the GP and RRT2. It stalled at a light, didn't want to relight, so I ended up having to bump start it. Tester seemed impressed enough to sign off on my licence.

Oldhaven... I sent an email off to DepoRacing to ask what that unit draws. Some heaters apparently pull a fair amount.. not that I'm concerned, because I have an Alton... just curious.
 

Magnetoman

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VOC Member
I took my M/C test on a DBD34 with the GP and RRT2.
Some heaters apparently pull a fair amount.. not that I'm concerned, because I have an Alton... just curious.
At the time I took my test in So. California it was written-only, you could get a motorcycle license at age 15-1/2 (16 for a car license), and there was no helmet law.

All these units seem to use the same Bosch sensor so should have the same power requirement. Freestanding mine draws 1 Amp after the initial ~30-sec. warmup (~1.5 A for that). I've never measured it when underway but it should require less since the exhaust helps keep it warm. I power mine with a separate sealed 2.2 A-hr lead acid battery to give it a nice, stable voltage. This wouldn't work if I wanted a permanent installation, but I use the meter to get the jetting correct after which it's 'set and forget' (until the needle jet wears out). My meter records for a max. of 44 min. so the battery I picked gives me the combination I want of size vs. capacity.

On the subject of needle jets, I have a special inside micrometer that measures them to 0.0001". I had measured the needle jet in my Catalina prior to a ~1200-mile ride a year ago and by the end of that ride it had enlarged by 0.0004"-0.0005", i.e. was worn out.
 

Cyborg

Well Known and Active Website User
VOC Member
On the subject of needle jets, I have a special inside micrometer that measures them to 0.0001". I had measured the needle jet in my Catalina prior to a ~1200-mile ride a year ago and by the end of that ride it had enlarged by 0.0004"-0.0005", i.e. was worn out.
Meant in a good way.... the inside of your head must be a strange and unusual place.....I feel like Carter peeking into Tutankamun's tomb. You are probably the only person on the planet that knows exactly when his needle jet is knackered.
 

Magnetoman

Well Known and Active Website User
VOC Member
You are probably the only person on the planet that knows exactly when his needle jet is knackered.
Hmm, maybe I shouldn't mention that I flow test my main jets[*] If nothing else, these examples show you can take the physicist out of the lab, but you can't take the lab out of the physicist. Or something like that.

[*] In a test of a dozen '500' jets, 25% of them were as much as 3-1/2 sizes too large or too small.

The photo shows that I had three "blankets" sewn with Velcro to accommodate being wrapped around pipes of a wide range of diameters. One is upside down so you can see the mating strip of (white) Velcro that's on the back side of all of them. The additional small patch of material goes around the sensor's cable to seal that opening. Also shown sitting on one of the blankets is the Innovate "sniffer" that I modified by attaching a piece of brass to keep the inlet from sitting flush against the wall where the air flow is minimum. I probably got the material from McMaster-Carr but it was over a decade ago so I can't be sure. As I mentioned in a previous post, as far as that sniffer goes up the exhaust pipe, it doesn't go far enough to escape the air sucked back up the pipe when the engine is running.

26750
 

Cyborg

Well Known and Active Website User
VOC Member
Thanks again.
My father had a PHD in microbiology so as a child I got to play in the lab and see some interesting things. He spent some time doing experiments in the local cyclotron....fascinating world. He would have loved it if I took a similar path. Unfortunately I was more interested in motorcycles and then he made the mistake of taking me with him on sabbatical to the University of Sussex. Somehow I ended up in a pub full of VOC members. A fellow by the name of Bill Lawless helped feed my habit and the rest is history as they say.

I wonder how my recently purchased jets (from China) would fair in one of your testing sessions. I suppose ultimately it won't matter what number is on them if the A/F gauge tells me what I need to know. Might cause some frustration getting there. I had thought about drilling out the existing plot jet just to get me into the ballpark. When I pulled out the drill set a look at the #79 drill bit made me think life is too short and Ebay was a better option.
 

Magnetoman

Well Known and Active Website User
VOC Member
Unfortunately I was more interested in motorcycles...
That's no excuse. Someone gave me a ride across Des Moines on a Triumph Thunderbird when I was 8 or 9 and I was hooked for life on motorcycles, but I still manage to be hooked for life on physics as well. My career as an experimental physicist was sparked in no small measure by my love of mechanical objects resulting from having to ... er, I mean, being privileged to get to repair my British motorcycles.

I wonder how my recently purchased jets (from China) would fair in one of your testing sessions. I suppose ultimately it won't matter what number is on them if the A/F gauge tells me what I need to know.
Even with an A/F gauge, knowing you need to, say, go two sizes larger and then swapping for a jet that is one size smaller despite being marked two sizes larger can be frustrating. I suppose that zeroing in on the correct jet using a batch marked with random numbers could be "entertaining," but it's not the kind of entertainment I enjoy. Then consider trying to do this on a twin with just the one A/F sensor, where one replacement jet could be larger than the marked size and the other one smaller.
 

Cyborg

Well Known and Active Website User
VOC Member
I have a whole litany of excuses but have a feeling none of them would fly. I did end up getting a decent job in the motorcycle industry and my father ultimately turned out to be quite happy about that.... at least he seemed happy. Maybe it was the fact that I wasn't incarcerated. The employment situation in anything related to the sciences at the time was dismal. You were fortunate to have the brainpower and gumption.

Yes jetting a twin with questionable jets would be painful. A CBX would probably cause a person to hang themselves.

When you test the jets, do you measure them for flow or measure the hole? I could probably check main jets without too much difficulty, but the primary jets are another thing.
 

Magnetoman

Well Known and Active Website User
VOC Member
When you test the jets, do you measure them for flow or measure the hole?
A 200 jet has nominal diameter 0.048" and a 210 has 0.049", so one could measure to that accuracy if forced to, although flow depends as the square of diameter so measurement errors are magnified. Unfortunately, the flow also depends linearly on the "contraction coefficient" of the edge of the jet, which varies from 0.62 for a sharp edge to 0.97 for a rounded edge. From this it can be seen that slight differences in the shape have significant effects on the flow. I'm told operators sat at the jet calibrating instrument (a flow meter with fixed pressure head, held at constant temperature 15C and with standard fuel of density 0.710 g/cu.cm) and slightly burnished the edge of each jet until it flowed what it should.

As historical speculation, there was close cooperation between Amal and Mikuni and Mikuni jets almost have the same numbers as Amal. The slope of flow rate vs. jet number for Mikuni jets isn't quite as steep so my speculation is they used the same testing rig as Amal did, but the density of their "calibration fuel" was a tiny bit lower and/or the viscosity was a tiny bit higher.

Fluids, of which air is one, have similar flow behavior if they are in the same range of Reynolds numbers. Somewhere I have my calculation that shows that light air being rapidly sucked through a jet on my flow bench is in the same range as much denser gasoline flowing being sucked more slowly through the carburetor. This makes life easy.

I have a plate that bolts to my flow bench that has a single tapped hole for a jet. I also have a jet that I soldered shut that I use to 'zero' the unit. It's not like I jet bikes for a living so I can "calibrate" a set of larger and smaller ones than I think I might need so when I find the bike I'm working on a little too lean at 200 I can replace it with a 210 knowing that it's a 210.

I should say I rely on an average curve of cfm I measured on the flow bench vs. jet number, not on an absolute calibration. Thanks to eBay I have a huge collection of jets from 50 to 1700. Taking the 500s I mentioned earlier, 8 of the 12 clustered closely together in air flow with the other 3 outliers. For my purposes I ignore those 3 and draw my curve through the center of the cluster. Having done this for other jets I have a curve I can rely on when checking any other random jet.
 

timetraveller

Well Known and Active Website User
VOC Member
Cyborg, it is a very small world and your comments in #25 above show that many years ago we might have met. I worked at the Royal Greenwich Observatory at Herstmonceux and we had weekly joint seminars with the Astronomy group at the University of Sussex. On the walk from the car park to the lecture theatre there was often a Comet parked under one of the buildings so whether that was owned by someone in your family only you can tell us. I was also a regular attender at the Brighton section of the VOC and Bill Lawless was a personal friend. As an aside he is still alive but not as well as could be wished. Therefore at some time we might have known each other at those VOC club nights. The section is now known as the Sussex Section and very ably run by Dick Sherwin who was also a member in those days. Another person you would have known is Roy Robertson, who until recently raced an Egli while in those days he had a Norvin. Good Club this, isn't it?
 

Cyborg

Well Known and Active Website User
VOC Member
First off, my humble apologies to Oldhaven for the page long highjack.

The Comet didn't belong to anyone in our clan. At the time only my older brother had a Vincent (C Twin). There is a good chance you met my father. Although he was there doing research in microbiology, he had a keen interest in astronomy and its unlikely he would have missed a seminar had it been available to him. One of my regrets in life is the fact that he offered me his telescope (complete with motor drive etc.) once he couldn't drag it out to the countryside anymore. I was in the middle of a move at the time and in a moment of weakness decided to pass and he donated it to the local observatory.
I don't recall how many VOC meetings we went to, but a good few, certainly enough to get to know Bill. He went out of his way to make us feel welcome, plus he helped line me up with another mongrel.. a mid 30's OHC Norton and although it changed hands through the family over the years, it is safely tucked away in the corner of my garage waiting for its turn at some TLC. A few years later I was back over there and he helped me with..yet another mongrel, an Inter motor stuffed into a wideline featherbed. Long story short, it was sold many years ago and split up. Somehow the engine and frame ended up back in my garage as well.
The name Roy Robertson has had me scratching my head a few times wondering why it sounded familiar. Maybe something to do with Bill cursing Roy because he had talked him into yet another clapped out Shadow?
Not too long ago, I tried to find Bill, but had no luck. If you could message me his contact info, it would be greatly appreciated.... and yes it is quite likely we would have met.

Bill also helped me find bits and pieces for a 650 Triumph that I was turning into one of those dreaded cafe racers. He took me to this place and negotiated a reasonable price on an alloy tank and seat.
Tank:Seat.jpg
 

Cyborg

Well Known and Active Website User
VOC Member
BTW, yes the plan is to use the second plug so hence the inquiry about the software. I purchased the appropriate coil with that in mind and want to reap the benefits of the second plug... assuming there are any.
The duel plug conversion was one of my first real projects on the mill, so I'm damn well going to use it. I just have to come up with some of that sky hook engineering and sort out the linkage for the stock decompressor. Real estate around the lifter rod is limited to the point where a normal length ET168 likely won't fit.
 
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Cyborg

Well Known and Active Website User
VOC Member
I think I need to clarify what I wrote above a bit. I can see that it can be confusing. The way this ignition works is that during installation it is timed to TDC with an LED and degree wheel in the normal manner (or at least normal for an electronic ignition). After that when the engine has been put into what you want for a starting position you turn on the ignition and and kick . It will fire at 0*/TDC when it sees it for the first time. After that it goes to its programmed settings as shown in the chart above. I think 12* would be a bit too advanced for that first firing, but it should not kick back at 0*. The ignition will reset to the initial resting state if it sees no motion of the encoder, (if it does not start) and the starting sequence firing at 0* TDC will be re-enabled. I do notice that Pazon and some other starting curves are lower than 12 (about 5*) at starting and low idle and flat up to about 500RPM, so I was curious what your experiences have been.
I vaguely remember a conversation with that fellow from Power Arc regarding the firing at 0*. It was in reference to one he installed on a rather large version of a HD engine. He claimed he could hand crank it into life without difficulty.
So I guess my first question is... can you reprogram that initial 0* ?
I know you can reprogram everything else in the way of curves, rev limiter, on time...
A quick look around for info on ignition settings while cranking is all over the map. One reference says most engines are happy at 0* but some require 20. All of them are auto related, so cranking at higher speeds that you'll get with your right foot. Robert is the only fellow I know who can kick a motorcycle over at those sorts of speed.
 

Oldhaven

Well Known and Active Website User
VOC Member
My Rapide is still buried in a snow bound garage up north right now. I am thinking about trying the attached curve profile on mine when I get to see it again next month. With triple sparks on starting the first spark is a single spark at 0* when it sees the TDC slot for the first time.
It has to be this way since the ignition needs this initial information to set itself. The next spark event with the current default program is three sparks at 12*, 5* and 0* BTDC if the kick is a good one and still rolling. With three sparks I cannot program that subsequent spark at 4* or 5* BTDC
as is recommended for Vincents in general since there
must be 5* between sparks for the coil to recover. With 2 sparks the
starting curves after the 0* initial spark could be at 5* and 0* BTDC.
It is possible to get two sequential spark events on a kick with a good long stroke.
This could be even more useful to those with a starter onboard. If the
encoder comes to rest between kicks because the bike does not start, the program resets itself immediately to its initial state to protect against reverse rotation causing problems with the encoder slot
count. If I put a manual switch into the sensor wire not used for the VOES I
could switch on a starting curve like this then switch back to triple
sparks after starting. It's worth an experiment to see if starting becomes more positive. I am also going to change the default curves to set the first triple spark at 10* rather than 12*
I think this "programming your own ignition" thing could be fun.

vincent 5 degree 2 sparks.jpg
 

Cyborg

Well Known and Active Website User
VOC Member
Hmm, maybe I shouldn't mention that I flow test my main jets[*] If nothing else, these examples show you can take the physicist out of the lab, but you can't take the lab out of the physicist. Or something like that.

[*] In a test of a dozen '500' jets, 25% of them were as much as 3-1/2 sizes too large or too small.

The photo shows that I had three "blankets" sewn with Velcro to accommodate being wrapped around pipes of a wide range of diameters. One is upside down so you can see the mating strip of (white) Velcro that's on the back side of all of them. The additional small patch of material goes around the sensor's cable to seal that opening. Also shown sitting on one of the blankets is the Innovate "sniffer" that I modified by attaching a piece of brass to keep the inlet from sitting flush against the wall where the air flow is minimum. I probably got the material from McMaster-Carr but it was over a decade ago so I can't be sure. As I mentioned in a previous post, as far as that sniffer goes up the exhaust pipe, it doesn't go far enough to escape the air sucked back up the pipe when the engine is running.

View attachment 26750
Sorry if I sound a little thick, but I'm assuming the blanket just extends the exhaust pipe so there is no oneway valve effect and you chose a blanket as opposed to pipe so it could be used on a variety of exhausts yes/no?

I ordered some bits for my rear sets from McMaster-Carr. I live north of the 49th, but got them shipped to a place in WA state (about 5 minutes from here) to simplify things. When they figured out the order was eventually going to Canada, they had some sort of meltdown and would have cancelled the order if they had caught it in time. They seemed to be worried about it causing some sort of international trade infraction.

I started a separate thread on A/F gauges https://www.vincentownersclub.co.uk/threads/air-fuel-gauge-02-sensor-lambda-sensor.11481/ so if you have the patience to reply, you could do it in that thread if you wish.

Thank you for your post about jets and contraction coefficient. I knew it was a factor (although I didn't call it that) and was wondering what these Chinese jets will be like. Highly unlikely that they have folks sitting at jet calibrating instruments.
 

Cyborg

Well Known and Active Website User
VOC Member
I think this "programming your own ignition" thing could be fun.
Well you have fun... hopefully I can extract the results from you in exchange for beer or eternal gratitude.
I'm still recovering from figuring out the indexing plates on the dividing head. The combination of attention deficit disorder and the Machinery's Handbook is all the fun I can take.
 

Magnetoman

Well Known and Active Website User
VOC Member
I'm assuming the blanket just extends the exhaust pipe so there is no oneway valve effect and you chose a blanket as opposed to pipe so it could be used on a variety of exhausts yes/no?
Yes, sort of. The blanket extends the exhaust, just as an added section of pipe would, but unlike a pipe it collapses on itself to become a one-way valve if the flow tries to reverse. It's provides a "universal" solution, i.e. it's OK but not ideal. I have three Gold Stars so the header to which I welded a bung is an ideal solution for them.
They seemed to be worried about it causing some sort of international trade infraction.
I suspect the law they fear violating is ITAR - International Traffic in Arms Regulations. You may not think bolts for rear sets are weapons, but the regulations are a, well, minefield. Leaving the U.S. with a variety of widely-available commercial software on our laptops is considered illegal trafficking in arms.
 

ClassicBiker

Well Known and Active Website User
VOC Member
I ordered some bits for my rear sets from McMaster-Carr. I live north of the 49th, but got them shipped to a place in WA state (about 5 minutes from here) to simplify things. When they figured out the order was eventually going to Canada, they had some sort of meltdown and would have cancelled the order if they had caught it in time. They seemed to be worried about it causing some sort of international trade infraction.
Magnetoman beat me to the punch on M-C's problem. What is funny is Canada is one of if not the only country that has successfully petitioned and received ITAR exemption, based on the 1963 Defense Development Sharing Agreement.
Steven
 

Cyborg

Well Known and Active Website User
VOC Member
Magnetoman beat me to the punch on M-C's problem. What is funny is Canada is one of if not the only country that has successfully petitioned and received ITAR exemption, based on the 1963 Defense Development Sharing Agreement.
Steven
Wonder if we could apply that to steel and aluminum? Sorry.. me bad... wrong forum.
 

Cyborg

Well Known and Active Website User
VOC Member
Yes, sort of. The blanket extends the exhaust, just as an added section of pipe would, but unlike a pipe it collapses on itself to become a one-way valve if the flow tries to reverse. It's provides a "universal" solution, i.e. it's OK but not ideal. I have three Gold Stars so the header to which I welded a bung is an ideal solution for them.
I suspect the law they fear violating is ITAR - International Traffic in Arms Regulations. You may not think bolts for rear sets are weapons, but the regulations are a, well, minefield. Leaving the U.S. with a variety of widely-available commercial software on our laptops is considered illegal trafficking in arms.
I wonder if a set of small doors similar to the ones used on the front of a doodlebug engine would work or if they would create enough back pressure to alter things.


I checked the letter from McMaster and they just referred to Export Administration Regulations (EAR), but I assume ITAR is buried somewhere in there. They said I could go to the site and read the regs, but I think I'll stick with the Machinery's Handbook, It's probably a little lighter going.
 

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