Trying to start bike (Kawasaki EX-250), no luck

[EWflyer]

Spent all afternoon trying to get my Kawasaki EX-250 started for the first time on it's new Microsquirt.

Here's where I stand: I can only get it to fire up by holding the throttle open about 20 to 25%. The bike starts immediately then swings between idle speed and around 3,000 RPM. If I let go of the throttle it dies, and if I hold onto the throttle at the 20 to 25% opening it dies anyway after a few swings between idle speed and about 3,000 RPM. No backfires.

Where do I go from here? I don't have any experience tuning an engine so I don't know what it needs. My VE table is probably crap but I wouldn't know any better. Also, like a lot of small engines this little EX-250 doesn't seem to be pulling much vacuum so I may be headed for an Alpha-N solution.

I'd certainly appreciate any help, knowledge, or tips from any of you who've "been there, and done that"

[24c]

At least it starts, but you could post a datalog or msq, and then others could look at it for you, and you could check for other issues.

As it starts with the throttle open, your fuelling must be out. I can't remember where, but I think it was Peter Florence who mentions if you're starting with the throttle open, the engine is ???? It was in one of the manuals, getting started etc.

As I am a newbie at running up my bike too, I would be putting a flat advance curve in my table...ie 10 degrees across everything up to 4000 rpm. Then any variations on MAP will not affect the running once it's warm. Then adjust the required fuel, and or VE Table values around your idle speed, until it will start on the button from hot.

Later you can explore Alpha N

PS Just out of curiosity, what MAP readings do you see on your gauges?

[EWflyer]

Lots of questions for you, please bear with me. I listen and can be taught!

I would be putting a flat advance curve in my table...ie 10 degrees across everything up to 4000 rpm.

I guess I should have mentioned that my EX-250 project it "Fuel only" so I don't have the added complexity of ignition to deal with right now. I've left the bike's original, and very simple, ignition system in place.

but you could post a datalog or msq, and then others could look at it for you, and you could check for other issues

Yes, I need to learn about this. I've mostly ignored this area of the Microsquirt world up till now. Help me out here, a datalog file ends in ".msl" right? And these .msl datalog files are read using MegaLogViewer?

Do I need MegaLogViewer? Or is there some other development that people are using to analyze their datalogs?

And the "msq" is file type for the "MegaTune Settings File" that applies to your project, right? Until just now I didn't realize that .msq was the file type name (damn, do have I got a lot to learn!) So the .msq is the file that you load right after you open up MegaTune.

So, when someone wants to look at my .msq file, they would just run MegaTune and open up my .msq file. Is that correct? And how do you go about attaching the .msq and .msl files in a forum post?

Do I need MegaLogViewer? Or is there some other development that people are using to analyze their datalogs?

Then adjust the required fuel, and or VE Table values around your idle speed, until it will start on the button from hot.

I think I might have to adjust some VE Table values (right now) just to achieve a stable idle. My VE table is probably a disaster. I'm realizing that my VE table is ridiculously optomistic about MAP. My map bins are set from 100 down to 30 which I'm pretty sure I'll never see on this bike, but I didn't know any better until I began trying to start it yesterday.

At my bike's usual idle speed, around 1300 to 1500 RPM, with a MAP somewhere in the mid to high 80's, I've got VE numbers like 66, 70, 69, and 73 in the table. That's very wrong, isn't it? Way down below these numbers, at MAP values I'll never see, are numbers like 29, 37, 32, 39 which I understand are more normal for idle.

[24c]

Yep, get MegaLogViewer, it's a free download, with a paid option as well, it'll really help in solving /seeing problems, specially when you grab a log.

Yes, if you post a msq they can be read by others, and msq are read by MegaTune and TunerStudio. Have a look at TunerStudio, you might find it more intuitive, but it might take a little getting used too.

Back to your bike, as you're are running ignition only, you'll be taking a feed off the coil side perhaps to generate a Tach signal? this can be prone to interference, so this might be affecting your start up too. The ignition advance on your bike, does it have a vacuum pipe or TPS connection? If it does have the first one, you could just block it off, so variations in inlet pressure don't affect the advance, whilst you get some of your fuelling sorted.

[EWflyer]

I was editing my prior post, putting in more questions for you. So if you would re-read it to see those items, I'd appreciate it.

My project is "fuel only", no ignition.

The ignition advance on your bike, does it have a vacuum pipe or TPS connection?

When I said that this little Kawasaki was simple, I meant very, very, simple! The ignition advance is pre-programed into the ignitor box on the bike. Regardless of engine load condition it just starts at 13 degrees BTDC at idle speed and graduates to 42 degrees BTDC at 4,500 RPM, then it remains there at 42 degrees all the way to the 13,500 RPM redline.

So no vacuum pipe or TPS. There's not even a drawing in the owner's manual of the curve they used to get from the idle advance to the 4,500 RPM setting.

[24c]

OK, I reread some of your edited posts, what values do you see in the kPa, I only ask because I see weird stuff on my bike, and I have configured it correctly. What I saw when looking at the VE tables was the kPa staying in one place, but the gauge on TunerStudio showing a higher value...the issue was the VE table didn't go high enough.

Once I reset my bins (values in the columns) it made more sense, and I was able to tune my VE, plus where the req'd fuel was calculated at a value of 8 msec, but the VE table was so far out, such that the required fuel to get a stable idle with the default VE table values was actually 2.3msecs.

Understand re your ignition advance, obviously advance variations in your stock ignition curve will affect your attempts to resolve your fuelling issues, but you need to get closer to an idle rpm on starting.

Hope this helps.