Hello all,
We are using the Microsquirt on a 49cc Yamaha Scooter engine. It is a four stroke engine, SOHC, three valve (two intake one exhaust), fuel injected, engine code XF50W. We are using this engine on a school project to compete in the Shell Eco Marathon Challenge. The deadline is coming up, and we are in desperate need to get it running, so any help is greatly appreciated.
Attached is a tune that we used that got the engine started once. Starting was not repeatable at all, and it took a while to catch. Any suggestions or changes are much appreciated.
Microsquirt on Yamaha Scooter Engine - Won't Work
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Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Microsquirt on Yamaha Scooter Engine - Won't Work
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- with passamaneck.msq
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Re: Microsquirt on Yamaha Scooter Engine - Won't Work
Need: Compression, Fuel, Spark
Assume compression exists.
Fuel: is plug wet? does MegaTune read 'cranking' when you are trying to start it.? A log file of the start attempt would be helpful.
Spark: Can you see timing light flash? Have you confirmed that timing occurs when expected?
Assume compression exists.
Fuel: is plug wet? does MegaTune read 'cranking' when you are trying to start it.? A log file of the start attempt would be helpful.
Spark: Can you see timing light flash? Have you confirmed that timing occurs when expected?
Re: Microsquirt on Yamaha Scooter Engine - Won't Work
After cranking for more than 10 seconds, the plug is wet with fuel. Megatune reads cranking when the engine is cranking. Attached is a log file we took of start up.
As for the timing, we are fairly sure it is correct. The engine has started several times, and idled for a minute or two before we killed it. It just won't start back up.
As for the timing, we are fairly sure it is correct. The engine has started several times, and idled for a minute or two before we killed it. It just won't start back up.
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- datalog200903281515.xls
- (32.23 KiB) Downloaded 66 times
Re: Microsquirt on Yamaha Scooter Engine - Won't Work
- the motor cranks at 770 rpm? wow, that seems like fast cranking, but i'm not familiar with that little motor.
- unless you are at some extraordinary elevation, the MAP before cranking seems super low. has that been calibrated?
- why does the battery voltage suddenly pop up from 9.5 to 12v toward the end of the log file?
- did you cut off some of the data? the trigger +- sits right at -73 the whole time, i'm just wondering the path... maybe trigger issues.
- CLT is at 80 but it wasn't running. are you in a really warm climate?
seems that an important data point is that you have had it running before. have you tried different cranking PWs? starter fluid can help determine if that is your problem? do you have a scope to see that your ignition signals are as expected?
- unless you are at some extraordinary elevation, the MAP before cranking seems super low. has that been calibrated?
- why does the battery voltage suddenly pop up from 9.5 to 12v toward the end of the log file?
- did you cut off some of the data? the trigger +- sits right at -73 the whole time, i'm just wondering the path... maybe trigger issues.
- CLT is at 80 but it wasn't running. are you in a really warm climate?
seems that an important data point is that you have had it running before. have you tried different cranking PWs? starter fluid can help determine if that is your problem? do you have a scope to see that your ignition signals are as expected?
Re: Microsquirt on Yamaha Scooter Engine - Won't Work
well, My 2cents....
double and tripple check your tach settings, these are SUPER important when being aplied to a low CYL. count engine. I have just started a 2cyl motorcycle install, and getting tach input criteria set correctly makes all the difference.
if you have a lab scope it will help a bunch to see where the crank trigger is in relation to the coil firing, if no just pull the plug and make sure its firing while cranking.
If the stock ignition system is still in place I would recommend hooking it back up, and then just tune the fuel till it does everything right, and concentrate on cranking and afterstart settings till it is perfect. Then start looking at spark control. At least that way you will have ruled out fueling.
On mine I had to set the skip pulses setting (for a toothed wheel) 1 tooth past where TDC (according to my lab scope, actually was (best guess based on scope readings of stock coil firing and VR sensor) to keep it from kicking back against the starter, no matter what i did up to that point it would never start good. Once I did that, fires up smoothly every time.
double and tripple check your tach settings, these are SUPER important when being aplied to a low CYL. count engine. I have just started a 2cyl motorcycle install, and getting tach input criteria set correctly makes all the difference.
if you have a lab scope it will help a bunch to see where the crank trigger is in relation to the coil firing, if no just pull the plug and make sure its firing while cranking.
If the stock ignition system is still in place I would recommend hooking it back up, and then just tune the fuel till it does everything right, and concentrate on cranking and afterstart settings till it is perfect. Then start looking at spark control. At least that way you will have ruled out fueling.
On mine I had to set the skip pulses setting (for a toothed wheel) 1 tooth past where TDC (according to my lab scope, actually was (best guess based on scope readings of stock coil firing and VR sensor) to keep it from kicking back against the starter, no matter what i did up to that point it would never start good. Once I did that, fires up smoothly every time.