When you can't adjust a variable venturi carb easily, it is almost always a case of the tapered needle being worn and needing replacement. The taper is supposed to be continuous, but it will wear the most near the bottom, causing the mixture to be way too lean if you try to set the idle mixture right. The needles are only a few bucks.
This is indeed a neat gadget. But I did not see the actual circuit, which would have been quite interesting. Also a few more dtails in the photos would have been very welcome. My next bike will be a chopper, but I don't know what kind of engine it will have just yet. My last bike was OK to start, but the fuel mix settings were a screaming pain. When set for best power it would not start, when set for good starting it would not make power. Sold. Oh Well.
How about electronic fuel injection of a bike? Are the automotive injectors rugged enough for bike use?
I had a '67 BSA Thunderbolt w/ kick start. Nasty to start but always started on the last kick I had in me. After a couple of weeks I analized the process. I sat on the seat instead of standing on the starter, slowly rolled it and it started on the first time. Repeated from then on out. It was just playing with me.
Interesting design challenge to sync up with the motor within a single revolution.
Note that the actual timing requirements of the engine vary widely. Not only does it vary dependent on engine RPM but even more so by cylinder pressure and also by fuel mixture. Higher pressures burn faster and lower burn slower. Lean mixtures burn slower too. By way of example a classic Chevy V8 needs no more than 16* advance during cranking, 36* at full power/RPM, and 52* cruising. Due to the low cylinder pressure and lean mixture at idle optimum advance is up in the 40's but many mechanical setups cannot get there. An electronic mapping system with both RPM and MAP inputs can go a long way to optimizing the operation and efficiency of an engine.
Airplane ignitions have long had starting retard systems and so have some motorcycles.
Anyone interested in an extreme gadget here should investigate the Mega Squirt EFI system. An entire system build to facilitate expirementation and learning of how these things work.
Awesome idea and design! I'm going to build this ignition in a nose cone mounted variety for the Evolution motor. Maybe this will alleviate some of the hard starting issues with a high compression motor. The MSD brand single fire ignition that is installed now, is a big dissappointment. (Single fire refers to each cylinder spark firing individually. The factory ignition in an evolution motor fires both plugs at the same time, known as dual fire or wasted spark). The problem I am having is when the initial static timing is set for the best starting, the total advance, though adjustable to some degree, is too far advanced and causes pinging on most premium fuels. The range of adjustment isn't wide enough to keep the total advance manageable. The MSD ignition allows the use of a VOES (Vacuum Operated Electronic Switch) to control the ignition advance switching point using manifold vacuum. These switches are inherently finicky. When they work, they work good, when they don't work... The circuit as designed will allow me to control the advance without this switch. I should be able to tailor the ignition "map" to my motor's needs. Now all I need is an ICU with a USB port to be able to edit the ignition timing while running...
@Edward - This is simply a great project, I love this machine. It's nice to see we have ways of modifying this monster.
"I know a lot of Panhead owners who swear their motor starts on the first kick, which is probably true for the most part. But they will also tell you everything must be just right for it to come off on the first kick. I've also watched a few guys kick until they were blue in the face when things weren't just right."
Ohh yes not everyone knows the art of riding a Harley. As you said the rider need to know the correct technique and respect, this comes through experience.
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