Hard start has me thinking

[Donk]

I had an 04 FJR that would occasionally give me a hard start, which is part of the reason I got rid of it. It would usually happen after sitting for a few weeks, even on a battery tender. My S10 gave me one hard start after the one and only time I filled it with high octane gas. I burn regular now, with out any problems. One time when it was really hot outside, it acted liked it wouldn't start, but I went WFO and it fired. When its hot out this is my starting procedure. Kill switch off, turn key on, flip kill switch to run and immediately hit the starter button. When I do this, it turns over a couple more times than usual before firing, but when the injectors fire, the engine is already turning and will fire before they have a chance to flood the cylinders.

All of this could be BS thinking on my part, maybe a few of the more knowledgeable readers will chime in.

Interestingly enough on one of my hard start occasions I was scared the bike was going to strand me. It would start but certainly not easily. After filling the bike with premium the hard start went away and never returned. This is what lead me to believe the hard start was caused by "bad gas" the previous tank full.

 

[Koinz]

Our Yamaha dealer on the island is very bad. HOWEVER, I mentioned the "hard start" to their tech one day, and he told me that he's heard of it discussed before during dealer conferences, and it's caused by a mixture rich condition caused by a bug in the ECU. He claims the fix that Yamaha has asked dealers to suggest for it to get it to start right away is the following:

(1) Identify hard start and stop cranking
(2) Turn kill switch to "kill" position
(3) Turn off key
(4) Wait 5 seconds
(5) Turn on key
(6) Turn kill switch to "run" and IMMEDIATELY start cranking
(7) Bike starts

The two times I've experienced the hard start the above has given me an immediate start, almost like a normal start!

I haven't had a hard start in a long time, but this would not surprise me. If it is a bug, shouldn't Yamaha come up with a software flash to fix it? I wonder if there's a service bulletin on this somewhere.

 

[arjayes]

While I don't disagree with your list, most owners are not going to be able to easily provide a data point for everything you have listed. It might be more constructive for the forum members if you trimmed that down to a simple list of questions, and where necessary, an explanation of what data you were looking for, if there is a serious attempt to gather data from multiple hard start events. Starting a Sticky for just that data gathering might help too.

As to the wankers that programmed this originally... Don't forget human nature. They didn't start with a blank slate, they took 90% of what "they always do" and tweaked that to get the end results. Their process is likely part of the problem, which is why this issue crosses platforms.

I don't expect the limited amount of data to provide a true answer. I do expect that the commonalities will start to become apparent at some point, which may help people to understand and avoid the problem more. No issue experienced by so many people is truly random.

I'll continue to beat the drum that the ECU should keep detailed data logs. The ECU is a computer that runs software, and that software makes decisions based on data inputs. There are M sensor input and N control outputs. If all M input and all N outputs are recorded continuously while the bike is running along with a timestamp for each data record then it becomes easy to post-analyze what happened. It would shock me if the engineers at Yamaha did not build in a mechanism like this to support their internal software development and debug.

I realize that I'm talking about the way things should be vs. the way they apparently are. Not much help to people who are experiencing this problem. But for those of you who have factory contacts (fredz43?), maybe drop a card in the suggestion box?

That idea that any owner would maintain detailed records of everything that affects the EFI on the bike in anticipation of a hard start is pretty silly. Nobody is going to do that preemptively, and you never know when a hard start is going to happen. Certainly no mortal could reconstruct the data from memory after it happens. The only sensible way to attack this kind of problem is for the computer to record the data. Then when a hard start occurs all the data that led up to it is available and the whiz kids at Yamaha should be able to figure it out.

 

[scott123007]

I think if we were all out riding our bicycles or doing jumping jacks instead of sitting on our asses typing out wish list of solutions, we could just push start our bikes when this happens and that would be the end of it. ;D

 

[autoteach]

I'll continue to beat the drum that the ECU should keep detailed data logs. The ECU is a computer that runs software, and that software makes decisions based on data inputs. There are M sensor input and N control outputs. If all M input and all N outputs are recorded continuously while the bike is running along with a timestamp for each data record then it becomes easy to post-analyze what happened. It would shock me if the engineers at Yamaha did not build in a mechanism like this to support their internal software development and debug.

I realize that I'm talking about the way things should be vs. the way they apparently are. Not much help to people who are experiencing this problem. But for those of you who have factory contacts (fredz43?), maybe drop a card in the suggestion box?

That idea that any owner would maintain detailed records of everything that affects the EFI on the bike in anticipation of a hard start is pretty silly. Nobody is going to do that preemptively, and you never know when a hard start is going to happen. Certainly no mortal could reconstruct the data from memory after it happens. The only sensible way to attack this kind of problem is for the computer to record the data. Then when a hard start occurs all the data that led up to it is available and the whiz kids at Yamaha should be able to figure it out.

As I shouldn't know about it and shouldn't have seen it, I wont say the brand that has it, but I will say that this exists (and most likely with all brands) but for this particular brand you must have a "dongle" to unlock the feature and then it takes a very skilled professional (i.e. not your above average mechanic, try factory level calibration engineer) to manage the data and make corrections.


As for being able to push start it, probably just easier to twist the throttle to WOT when it doesnt start in the first 5 seconds.

 

[Donk]

I posted this elsewhere but I think its important to note. Ok Guys FWIW My Explorer has always started on first touch of the starter button. Only thing it does better than my S10! Today not so fast. Had to crank it 2-3 times before it fired. This happened several times during the day. Bike just did not want to start today. So maybe they all do it. You get the wrong combination of fuel, atmosphere, and events and the FI or ECU gets out of whack? I don't know but I now know that Yamaha isn't alone.

 

[samstoterau]

How have you been addressing a "hard start" to date? My observation is that if the flooding condition is recognized early, it is fairly easy to solve, but if you persist in trying to do a closed-throttle start for very long, you can get it in a pretty deep hole that's very hard to climb out of, especially with a bike that has a less-than-fresh battery and/or worn plugs. I've had four occurrences in three years and my protocol is that if the bike doesn't start normally within five seconds of closed throttle cranking, I immediately go WOT where it always starts within another 5-10 seconds of cranking.

If you can't find a workaround, I would be moving on too. If you truly require a "conclusive solution", I think you'll be selling as this is something that has been going on for three years with a lot of people looking at it with no solution or definitive answer on the horizon. Yamaha hasn't even acknowledged the problem exists. The dealers are generally clueless.

- Mark

Totally forgot about the WOT technique, really helped me out this am. Thanks

 

[MattR]

I had this yesterday. Temp 0c started bike normally then realised I hadn’t unlocked top box and had to switch it off again. When I tried to restart it stumbled and farted and felt like the world stopped spinning. Stank of petrol so I tried wot and it started


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[lund]

I had this yesterday. Temp 0c started bike normally then realised I hadn’t unlocked top box and had to switch it off again. When I tried to restart it stumbled and farted and felt like the world stopped spinning. Stank of petrol so I tried wot and it started


Sent from my iPhone using Tapatalk

Fuel injection can flood and is more prone to it if you do what you did.
When your motor is cold the ecu goes into rich mode and will run the bike in that mode till a set temperature is reached. If you started the bike and then a few minutes later shut it off as you did, then restart, it is typical to get too much fueling happening and a possibility of flooding.
Yes WOT will clear it out. No cure other then letting it reach operating temp.