ChinaRiders Forums - View Single Post - BD125-8 ZS190 swap and EFI conversion

glavey · 04-08-2019, 03:19 PM

A few things happened; good and bad. Problems; good and bad, were mostly sorted out.

1. I realized that the injector and/or the throttle body were poorly made (mostly the part where the injector in seated) and the spray from the injector (if it is even spraying and not dribbling) is hitting the walls of the TB and running past the throttle vane and right out to the air filter. After seeing that for the first time, I took the whole intake/TB assy. off and felt the bottom of the intake - bone dry. If there is fuel getting into the engine (there must be to get a BANG out of it), it is dribbling off of the walls into the intake port in no controlled manner. To remedy this, I will need to buy a new throttle body without a injector seat glued to it as well as have a hole in the intake manifold precision drilled and honed for the injector to sit in, so it can spray fuel directly on to the back of the intake valve. Both of those will take a considerable amount of time and some money as well.

2. I under-estimated the NEED to go out and ride in warm weather. This is my first motorcycle, I bought it last year around July. This was my first winter project and this will be my first spring where I have something to look forward to when the weather gets nice, instead of doing yard work and getting bitten by mosquitoes.

3. This is my first attempt at an EFI conversion and attempt at non-oem EFI in general. I should have started with something that had FI to begin with, then I would hopefully be able to focus on tuning (which is what attracted me to EFI in the first place - tuning, not circuit diagnostics and parts compatibility) instead of troubleshooting.

4. You all have seen how many things I have had to order for this project. I am very near the limit of what I want to spend on this project, this year

5. I am working on something that I love to use. When I get frustrated with something in the EFI system, I want to be able to go out and have a good ride to clear my head; I can't do that if the EFI system is ON by only bike. Having the bike be unrideable for large portions of time while waiting for parts to arrive is no good.

6. (a bit emotional) This thread, while I have thoroughly enjoyed sharing my findings, discoveries, and insights, has caused me some anxiety; I feel like I have to do something so I have something to post about and I have to post about what I have been doing. I know I don't really have to, no one has a gun to my head, but I started this thread and if I stop posting to it, I'll feel like I let people who browse this forum down. I realize this is all in my head and isn't correct, but I am mentally unable to let go of those feelings.

It is for these reasons that I am suspending, NOT CANCELLING the EFI portion of this project. To get the EFI system into good working order as described in #1 above, I need to either buy all of the things that will allow me to drill a precise hole in the intake manifold for the injector AND buy another TB (or remove the injector seat and patch the massive hole that is left in its place) without a injector seat AND wait around 1-2 weeks for everything to arrive AND then spend time installing everything. That is no fun when there are roads out there waiting to be torn up and sunshine waiting to make me feel nice and warm while giving me skin cancer.

Luckily, I made the EFI wiring harness in such a way that I can and have removed it from the bike along with most of the supporting parts in an evening (~4 hours) and installed the carb and CDI back on. Since it only took about 4 hours to take off, it should only take 8 hours to re-install, now that I know where everything needs to go and all the connectors are already there in the correct location.

I will still probably keep an eye on this thread (for things specific to this bike) and on the forum in general (for everything else) and answer questions and post my usual lengthy review/walk-through/write-up on things that I am doing or have done to my bike. I still have a few more somewhat inexpensive things I want to do like re-pack the exhaust with a quality packing material, not the wafer-thin sheet of fiberglass that they have in them from the factory, the $15 grom shock mod, and replace the rear-shock-shaped-object with an oem honda grom one.

bogieboy; I am using wasted spark on this engine. There is only a single tooth on the flywheel/magneto that triggers once per 360 degrees, so the ECU and CDI can only fire the spark plug once per 360 degrees (at the end of the compression stroke and the end of the exhaust stroke), not once per 720 degrees, as would be needed for non-wasted spark. Also, I have had the engine spinning using the starter motor and have synced the timing that the ECU says it should be and what it is on the engine. 10 degrees BTDC on the engine matches the ECU's 10 degree base timing.

Those aftermarket CDI boxes for automotive engines probably have a tachometer output wire that can give a signal to the ECU and they probably don't mess with potentially shared signals like crank speed by grounding one of the leads. The 190's CDI could be used with the microsquirt if I could build a small circuit that could duplicate the crank VR sensor's signal into two separate, isolated outputs. But, I don't have the skills to do that; I already have difficulty with arduinos, making something that is used to assist in the control of an engine is way beyond me.

Also, those ignition boxes will probably accept a 5v square wave input from an ECU or sensor; our motorcycle CDIs need a signal that goes high, crosses 0 volts, and goes negative (again something that I could build, but my lack of skills are stopping me). The microsquirt only has logic-level outputs for sparks; you cannot directly drive a coil from it without hardware modifications.

Sorry to stop progress on this so abruptly, but I must ride, be it with injectors or carbs.

If anyone has any questions that they wanted answered with regards to anything I did or said I was going to do with my bike, please go ahead and ask.

EDIT: Just had the bike started up for the first time. Loud even with the silencer in. Vibrates like a harley at idle. Big-ass smile on my face. I'm gonna miss the counterbalancing the 125 had. I'm letting it cool down so I can do an oil change and then take the new engine for its first inaugural ride. I'm keeping the wideband controller installed on the bike; once I get/make a gauge that will display the AFR, I'll add the sensor back into the exhaust to aid my tuning. I'll try (no promises) to take a short video showing how the bike sounds.

04-08-2019, 03:19 PM	#81
glavey Join Date: Oct 2018 Posts: 74	A few things happened; good and bad. Problems; good and bad, were mostly sorted out. 1. I realized that the injector and/or the throttle body were poorly made (mostly the part where the injector in seated) and the spray from the injector (if it is even spraying and not dribbling) is hitting the walls of the TB and running past the throttle vane and right out to the air filter. After seeing that for the first time, I took the whole intake/TB assy. off and felt the bottom of the intake - bone dry. If there is fuel getting into the engine (there must be to get a BANG out of it), it is dribbling off of the walls into the intake port in no controlled manner. To remedy this, I will need to buy a new throttle body without a injector seat glued to it as well as have a hole in the intake manifold precision drilled and honed for the injector to sit in, so it can spray fuel directly on to the back of the intake valve. Both of those will take a considerable amount of time and some money as well. 2. I under-estimated the NEED to go out and ride in warm weather. This is my first motorcycle, I bought it last year around July. This was my first winter project and this will be my first spring where I have something to look forward to when the weather gets nice, instead of doing yard work and getting bitten by mosquitoes. 3. This is my first attempt at an EFI conversion and attempt at non-oem EFI in general. I should have started with something that had FI to begin with, then I would hopefully be able to focus on tuning (which is what attracted me to EFI in the first place - tuning, not circuit diagnostics and parts compatibility) instead of troubleshooting. 4. You all have seen how many things I have had to order for this project. I am very near the limit of what I want to spend on this project, this year 5. I am working on something that I love to use. When I get frustrated with something in the EFI system, I want to be able to go out and have a good ride to clear my head; I can't do that if the EFI system is ON by only bike. Having the bike be unrideable for large portions of time while waiting for parts to arrive is no good. 6. (a bit emotional) This thread, while I have thoroughly enjoyed sharing my findings, discoveries, and insights, has caused me some anxiety; I feel like I have to do something so I have something to post about and I have to post about what I have been doing. I know I don't really have to, no one has a gun to my head, but I started this thread and if I stop posting to it, I'll feel like I let people who browse this forum down. I realize this is all in my head and isn't correct, but I am mentally unable to let go of those feelings. It is for these reasons that I am suspending, NOT CANCELLING the EFI portion of this project. To get the EFI system into good working order as described in #1 above, I need to either buy all of the things that will allow me to drill a precise hole in the intake manifold for the injector AND buy another TB (or remove the injector seat and patch the massive hole that is left in its place) without a injector seat AND wait around 1-2 weeks for everything to arrive AND then spend time installing everything. That is no fun when there are roads out there waiting to be torn up and sunshine waiting to make me feel nice and warm while giving me skin cancer. Luckily, I made the EFI wiring harness in such a way that I can and have removed it from the bike along with most of the supporting parts in an evening (~4 hours) and installed the carb and CDI back on. Since it only took about 4 hours to take off, it should only take 8 hours to re-install, now that I know where everything needs to go and all the connectors are already there in the correct location. I will still probably keep an eye on this thread (for things specific to this bike) and on the forum in general (for everything else) and answer questions and post my usual lengthy review/walk-through/write-up on things that I am doing or have done to my bike. I still have a few more somewhat inexpensive things I want to do like re-pack the exhaust with a quality packing material, not the wafer-thin sheet of fiberglass that they have in them from the factory, the $15 grom shock mod, and replace the rear-shock-shaped-object with an oem honda grom one. bogieboy; I am using wasted spark on this engine. There is only a single tooth on the flywheel/magneto that triggers once per 360 degrees, so the ECU and CDI can only fire the spark plug once per 360 degrees (at the end of the compression stroke and the end of the exhaust stroke), not once per 720 degrees, as would be needed for non-wasted spark. Also, I have had the engine spinning using the starter motor and have synced the timing that the ECU says it should be and what it is on the engine. 10 degrees BTDC on the engine matches the ECU's 10 degree base timing. Those aftermarket CDI boxes for automotive engines probably have a tachometer output wire that can give a signal to the ECU and they probably don't mess with potentially shared signals like crank speed by grounding one of the leads. The 190's CDI could be used with the microsquirt if I could build a small circuit that could duplicate the crank VR sensor's signal into two separate, isolated outputs. But, I don't have the skills to do that; I already have difficulty with arduinos, making something that is used to assist in the control of an engine is way beyond me. Also, those ignition boxes will probably accept a 5v square wave input from an ECU or sensor; our motorcycle CDIs need a signal that goes high, crosses 0 volts, and goes negative (again something that I could build, but my lack of skills are stopping me). The microsquirt only has logic-level outputs for sparks; you cannot directly drive a coil from it without hardware modifications. Sorry to stop progress on this so abruptly, but I must ride, be it with injectors or carbs. If anyone has any questions that they wanted answered with regards to anything I did or said I was going to do with my bike, please go ahead and ask. EDIT: Just had the bike started up for the first time. Loud even with the silencer in. Vibrates like a harley at idle. Big-ass smile on my face. I'm gonna miss the counterbalancing the 125 had. I'm letting it cool down so I can do an oil change and then take the new engine for its first inaugural ride. I'm keeping the wideband controller installed on the bike; once I get/make a gauge that will display the AFR, I'll add the sensor back into the exhaust to aid my tuning. I'll try (no promises) to take a short video showing how the bike sounds.
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