2005 EX-250 FI project bike cold startup test.

[greg737]

Now that winter has arrived I'm working on tuning my Fuel Injection project bike for cold weather startup.

To do this I've been tweaking the "fuel vs. temperature curves" in all of the fueling tables that apply to cold start-ups. This includes the following tables: Priming pulse table, Cranking pulse table, After-Start-Enrichment table, After-Start-Enrichment taper-off table, and Warm-Up-Enrichment table.

It's a balancing act between getting it rich enough to light off well in the cold without flooding it.

Link to original page on YouTube.

[cbdallas]

What a fantastic mod for a 250. Would LOVE to have this added to mine. Would be so nice to crank it & let it do it's thing without fiddling with the choke.

Don't feel bad about the tach....mine does the exact same thing. My 1994 & 2007 didn't do it, but my '05 does.

[greg737]

Don't feel bad about the tach....mine does the exact same thing. My 1994 & 2007 didn't do it, but my '05 does.

Thanks. I'd wondered if that tach behavior was something specifically wrong with my bike or whether it happened to others.

It always pops up when I rev the engine and it works fine afterwards. I know it's accurate because it agrees with the tachometer readout on my laptop computer when I've got it hooked up for tuning the FI system.

I guess there's just something in the tach's electronic components that needs a good kick in the butt before it will recognize the incoming tach pulses from the left ignition coil.

[choneofakind]

Mine does that too when it's cold. Seems to be a fairly common issue with pre-gens. Good to hear that it's accurate though.

[BigByrd47119]

Ignorant question here so please excuse me, but this an Ecotrons EFI system is it not? If so I'm trying to reconcile in my mind why your messing with it if it possess close-loop capabilities.

Thanks!

[Jiggles]

Originally Posted by BigByrd47119

Ignorant question here so please excuse me, but this an Ecotrons EFI system is it not? If so I'm trying to reconcile in my mind why your messing with it if it possess close-loop capabilities.

Thanks!

I believe it is not an Ecotrons system

[greg737]

Jiggles is correct. My system is a do-it-yourself configuration and I'm using a Microsquirt ECU.

Just like the Ecotrons ECU the Microsquirt is also capable of closed-loop tuning (i.e. rewriting/improving its own basic fueling table based on O2 sensor feedback). But to set it up for cold starts you have to manually configure and test the various small enrichment tables that augment the basic fueling table.

The Microsquirt uses four of these small "enrichment" tables to tailor startup fueling based on temperature: Priming Pulse table, Cranking Pulse table, Afterstart Enrichment table, and Warmup Enrichment table.

Acutally, it's been fun doing the fine tuning of these tables to give the bike "one press" startup in any temperature.

[cbdallas]

"give the bike "one press" startup in any temperature"

This is what made it most difficult to step back down to a 250 from a 650. Not fiddling with the choke would be a dream come true.

[choneofakind]

one press would be cool, but I've never had an issue with the choke on startup...

The main thing that draws me to EFI is being able to tune it to what I want and then leaving it, no matter where I take the bike, and the throttle response/smoothness. Plus, having to pull a vacuum on the petcock with a spare piece of hose every time that I de-winterize the bike or play with jets or run out of gas gets annoying. Start-up isn't really that bit of a sticking point with me tbh

[cbdallas]

Originally Posted by choneofakind

...having to pull a vacuum on the petcock with a spare piece of hose every time that I de-winterize the bike or play with jets or run out of gas gets annoying.

One of my older bikes (think it was the Yamaha XV920 or the Virago) had a "Prime" setting on the petcock....a glaring oversight on the Ninja. Very handy for synching carbs too.

I don't have any trouble getting the 250 started, but it has an annoying habit of speeding up after 10-20 seconds of running where I want it (somewhere between 2000-2500). During a 5-minute warmup, it speeds up 3-4 times. I come back out to the garage to find it screaming away at 3500-4000. I know...that speed is nothing to that engine...it's just loud and annoying in my garage. I miss the ability to push the start button and walk away.

[choneofakind]

Once mine starts speeding up like that, it will usually idle on its own just fine. Plus, I follow the theory of letting the bike warm up completely and evenly as quickly as possible by being all ready to ride when I start it, and just taking off (and then keeping it under 6k). The bike warms up to steady idle temp within a mile, and when it starts trying to bog at low rpms (usually at about a mile down the road as well), I know that the carbs are telling me it's time to turn off the choke.

[n4mwd]

Looks good Greg. I love those "one press starts".

Regarding the tach, its probably just a lubrication issue with the analog meter. At a low RPM, the meter gets a very low current which isn't strong enough to break it free. Once you rev up, it gets a stronger current that breaks it free and then it works fine. I'm not sure if its possible to add lubrication to it. I've never had mine apart, but analog meters are usually sealed. Just curious, but does this happen more when its colder or all the time?

[iluvwhite250r]

Originally Posted by greg737

Jiggles is correct. My system is a do-it-yourself configuration and I'm using a Microsquirt ECU.

Just like the Ecotrons ECU the Microsquirt is also capable of closed-loop tuning (i.e. rewriting/improving its own basic fueling table based on O2 sensor feedback). But to set it up for cold starts you have to manually configure and test the various small enrichment tables that augment the basic fueling table.

The Microsquirt uses four of these small "enrichment" tables to tailor startup fueling based on temperature: Priming Pulse table, Cranking Pulse table, Afterstart Enrichment table, and Warmup Enrichment table.

Acutally, it's been fun doing the fine tuning of these tables to give the bike "one press" startup in any temperature.

more info about your system and any links

[greg737]

Originally Posted by iluvwhite250r

more info about your system and any links

If you've got 15 minutes to burn watch this:

Link to original page on YouTube.

[greg737]

Originally Posted by n4mwd

Looks good Greg. I love those "one press starts".

Regarding the tach, its probably just a lubrication issue with the analog meter. At a low RPM, the meter gets a very low current which isn't strong enough to break it free. Once you rev up, it gets a stronger current that breaks it free and then it works fine. I'm not sure if its possible to add lubrication to it. I've never had mine apart, but analog meters are usually sealed. Just curious, but does this happen more when its colder or all the time?

I wondered if it isn't something just like you've described. As you say, low RPMs probably equals low current in the Tach signal, or not enough Tach signal pulses coming rapidly enough to wake up the guage. And yes, it does seem to happen more in cold weather.

I've actually got a spare EX-250 instrument panel on hand so I might take it apart to see if there's anything I could do to fix the situation or just learn about how it's put together.

[iluvwhite250r]

Thanks

[n4mwd]

Originally Posted by greg737

I wondered if it isn't something just like you've described. As you say, low RPMs probably equals low current in the Tach signal, or not enough Tach signal pulses coming rapidly enough to wake up the guage. And yes, it does seem to happen more in cold weather.

I've actually got a spare EX-250 instrument panel on hand so I might take it apart to see if there's anything I could do to fix the situation or just learn about how it's put together.

There is a little electronic circuit in there that converts the ignition pulses to an analog current for the meter. I've seen some bikes that make the analog meter redline for a split second on powerup. I'm wondering if its to avoid the situation like you describe.

But if you have a spare meter, maybe swap it out if you have time and see if it works better.

This morning I went out and it gave me a fit trying to get it started cold. Cold here = 70F. I was thinking about your FI bike the whole time. Hopefully when I get the EFI kit it will solve more problems than it creates.