HARD START

[Maxified]

Re: Very hard starting today

::017::

 

[Tippo]

Re: Very hard starting today

The hard start problem hit me again this year. After storing my '12 ST in a warm garage for 5 months (don't feel sorry for me, I was skiing) with a Battery Tender installed it turned over but refused to start. Smelled flooded. WOT did not work so I pulled the fuel injection fuse and ran the starter until it made a few pops. I replaced the fuse and ran the starter several times until it started. It popped and coughed a bit but I kept running the starter until it really was running. Last year it did the same thing. Never had a starting problem except after long storage. I would have been screwed without my charger. Last year I had a stock ECU. This year a reflashed ECU (ECU Unleashed).

Jeff

 

[Kenack]

Re: Very hard starting today

I had a non start issue today only 1 week since I started it several times for a short time after replacing my rear tire. My buddy has had the same issue when he started it and didn't warm it up before shutting down. I tried the WOT but it didn't work. Tried it several times 1/2 hour apart, nothing. Then pulled the fuse to fuel pump, cranked it for 30 seconds, nothing so shut off. Waited 10 minutes, put fuse back in, cranked it with no throttle and it tried to start so I gave it a little gas and it fired up. I let it warm up and shut it down after temp got to 170.

Next time it happens, if it does, I will pull the fuse, crank it 30 seconds to clear out fuel and wait 10 minutes, put fuse in try again.

Ken

 

[autoteach]

Re: Very hard starting today

What is the 10 minutes wait for? Magic pixies?

 

[Koinz]

Re: Very hard starting today

I'm not sure what thread I posted in, but I had mention that when I put new plugs in that I would gap them a little wider than what they came as. Since then, I've had a few miss starts but the bike fired right up after the missed startup. I'm not saying a slightly wider gap fixed the issue, but I will continue to monitor and report if I do encounter a hard start. My valves were adjusted and air filter replaced as well from an engine maintenance perspective.
My theory is that with a wider gap, the plugs won't foul as easily because the coils need to overcome a slightly larger gap so they have to build up more of a charge. Ymmv.

 

[Karson]

Re: Very hard starting today

Does anyone else think this should be stickied? I mean other than the headlight harness, we really run out of stuff to talk about. ::001::

 

[MrTwisty]

Re: Very hard starting today

Does anyone else think this should be stickied? I mean other than the headlight harness, we really run out of stuff to talk about. ::001::

Naw man, it's a figment of your imagination. Nothing here to see, move along.

All joking aside. I've actually learned that if I ever start the beast up when cold, I'd better let it run until it warms up a little before shutting it down or it may not start the next time. Yes, it's a problem, but some here think it's an operator problem and not a problem with the motorcycle. I tend to disagree.

 

[autoteach]

Re: Very hard starting today

Just because people wont listen to best practices and detailed explanations doesn't mean that it is a problem. Kind of like the over torquing/stripping of bolts/break of bolts that has occurred. Now, some people believe that those bolt issues are user error, but we all know that Yamaha has a problem with their bolts. Maybe we should have a sticky for poor bolt quality when torquing 4 times past manufacturer spec.

 

[markjenn]

Re: Very hard starting today

Just because people wont listen to best practices and detailed explanations doesn't mean that it is a problem. Kind of like the over torquing/stripping of bolts/break of bolts that has occurred. Now, some people believe that those bolt issues are user error, but we all know that Yamaha has a problem with their bolts. Maybe we should have a sticky for poor bolt quality when torquing 4 times past manufacturer spec.

Now you're just being silly. Someone starting a motorcycle exactly as the manual says to and not having it start because they didnt follow some arcane internet forum rule about warmup time in the previous start cycle has nothing in common with torquing a bolt 4x over spec.

- Mark

 

[Maxified]

Re: Very hard starting today

What's the data on those with a reflash, have any of these motorcycles had a hard start since redone?

 

[Koinz]

Re: Very hard starting today

What's the data on those with a reflash, have any of these motorcycles had a hard start since redone?

Forgot to mention a few posts up from this one. I have had the AC flash as well. Don't know if it has anything to do for or against a hard start condition. Again, no hard starts since adjusting valves, new plugs, air filter and flash. Maybe I'm not a good test case now, but will continue to monitor.

 

[EricV]

Re: Very hard starting today

Now you're just being silly. Someone starting a motorcycle exactly as the manual says to and not having it start because they didnt follow some arcane internet forum rule about warmup time in the previous start cycle has nothing in common with torquing a bolt 4x over spec.

Mark, you need to read your posts before you click on reply. Then stop and think about them in the context of reality. Then, sometimes, delete them w/o clicking on reply.

Not that we all can't benefit from that sometimes.

On topic - you act like every bike you ever owned just started when you followed the manual. You know better than that. : Pre-EFI bikes, you always had to learn what routine of choke, throttle, etc that particular bike liked, to start easy. Never mind really old bikes with manual advance timing and kick start. This is no different. Know thy bike. Yamaha EFI products, (products, because this is common with their sleds too), don't like to be shut down prior to full warm up. Often resulting in the hard start syndrome.

Karson - Sticky or not, some people will experience this, while others never will. Mostly the people that wash their bikes and then fire them up to ride into the garage will have this issue early on in their ownership.

 

[Don in Lodi]

Re: Very hard starting today

I agree. This is a FI bike and this is a fault that needs to be acknowledged and fixed by Yamaha. Could you imagine the outcry if Toyota, Chevy or Chrysler released a car that did this? Why does WOT affect a FI engine anyway? It shouldn't matter what you do with the throttle on fuel injection.

The thought being that wide open throttle lets in the maximum amount of air into the system allowing the highy evaporative fuel to be... evaporated. And my understanding is that with the throttle full against the stop, without the engine running to begin with, the ecm shuts off the pulse to the injectors. Wrong parameters for start up, shut off injectors.

 

[markjenn]

Re: Very hard starting today

The previous post has it right. It's been discussed before on this forum.... modern FI systems typically have clear-flood mode where WOT at startup is interpreted by the ECU as a flooded-start situation. It goes into a special mode where the the throttle plates are opened to purge the cylinders of fuel and the injectors are shut down to avoid introducing additional fuel. This mirrors the procedure applicable to older carb'ed engines which were much more prone to flooding. (The number of folks who know about engine flooding is gradually declining as fewer and fewer drivers have ever dealt with anything other than the virtually flawless fueling of modern FI engines - that's one reason why the WOT workaround we talk about is not as widely known as you'd think.)

Whether our S10's actually have this a clear-flood mode is not definitively known, but WOT typically works. We do have some folks who haven't been able to get it to work and have been able to use the fuel pump fuse trick. But there may be confounding variables - when you start pulling fuses, you likely are giving the system extra time to resolve on its own and many folks are also timid in applying the WOT technique - they don't crank long enough at WOT or they confuse the situation by alternating between WOT and throttle off. One would presume that the clear-flood mode requires the throttle to be held fully WO for the entire time until the flooding is corrected, the A/F ratio comes down into the combustible range, and the engine fires - back out of it even momentarily and you're back to adding more ultra-rich startup fuel to an already flooded engine.

Here's a cursory explanation:

http://autorepair.about.com/library/a/1/bl468.htm

One other thing.... I'm sure many of us are ignoring the 12K spark plug replacement interval as the bike generally runs fine well beyond this interval and if you check the plugs at 12K, they look great. But this might be the straw the breaks the camel's back in some cases - slightly worn plugs that are much more prone to gas fouling.

- Mark

 

[EricV]

Re: Very hard starting today

Very nice post Mark. ::008::

 

[ec90t]

Re: Very hard starting today

I haven't read all 43 pages of posts here, not even close, but has anyone addressed this issue as to whether the hard start issue comes about if you are one to pull the clutch in when starting a bike. Those of you that rode Suzuki's are use to pulling the clutch in for the starter to engage.

My take is that since the mapping is different when you pull the clutch in, it is also making the engine hard to start.

Maybe this has already been covered? If it is, just disregard my ramblings.

 

[autoteach]

Re: Very hard starting today

Now you're just being silly. Someone starting a motorcycle exactly as the manual says to and not having it start because they didnt follow some arcane internet forum rule about warmup time in the previous start cycle has nothing in common with torquing a bolt 4x over spec.

- Mark

I agree. This is a FI bike and this is a fault that needs to be acknowledged and fixed by Yamaha. Could you imagine the outcry if Toyota, Chevy or Chrysler released a car that did this? Why does WOT affect a FI engine anyway? It shouldn't matter what you do with the throttle on fuel injection.

Well, not exactly. You may think I am being silly, but I think everyone complaining about a hard start is a total idiot. The fact of the matter is that I have had 1 single start that required throttle application on my super, which I applied after the 3rd or 4th revolution without stopping the cranking cycle and it fired immediately. I have owned a Chevy Blazer, and now own a Subaru Forester. Both have had "hard starts". The blazer left me stranded many times because of it, the Subaru has not. I feel that the distributor played a role in the blazer's problems and the inability to resolve them. Now, how does WOT affect an engine:

It has been talked about many times, but I will cover it again in depth.

WOT on a carburetor engine decreases velocity through the carb's venturi, decreasing the vacuum that the air makes and thereby drawing less to no fuel in to the motor.

WOT on a FI engine is programming that has been put in the computer to provide a method of clearing a flood. this exists for the situation that everyone may encounter when short running a vehicle, or when parameters and situations have led to a hard start. Why can't the computer figure this out? Well, there are a few inputs that help the computer logic sort out exactly how much fuel to inject per cycle. Those include MAP, TPS, IAT, ECT, MAF (if the vehicle has it), BARO, CKPS, and O2S. The MAP sensor gives pressure of the intake, TPS the throttle position, IAT the intake temp, ECT the coolant temp, MAF the air flow in grams/s, BARO the barometric pressure (for relation to the MAP, to give delta), CKPS the crank speed, and the O2S the oxygen level in the exhaust. The only feedback is the O2S, and it can only read when properly heated. It also is a dumb sensor, like most of these they cannot see problems. For example, the oxygen level in the exhaust is rather high during a misfire or when cranking and not firing. this is because the oxygen is not consumed in the chemical reaction conversion of fuel. So, if it used this info what would it do? It would add more fuel to a situation that doesn't require it because the conditions that are present are a result of the occurrence and are not the occurrence itself. So, how do you program around this? You tell it to ignore O2 at cranking (and, it measures oxygen, not fuel, so it cannot measure afr anyway at startup), and you tell it to not do a full scale enrichment if the high oxygen levels coincide with a misfire that didn't have fuel trim out of specifications leading up to the misfire event. Are there conditions that are outside these conditions? Yes, you better believe it. But they do their very best to minimize that by testing in different areas with different conditions (Arizona vs Alaska, Florida vs Colorado).


As for how WOT affects both:
If you have ever done a compression test on a vehicle, you know that it is spec'd for WOT. This is because the pumping losses with the throttle closed is so high (no air to compress). Essentially, one of the benefits of starting with the throttle open is that you get more compression and big gulps of air. It is also one of the drawbacks, also noticed when kick starting large singles or twins or with bikes that have weak starting systems.


So, sticky this. It is the facts, and they are undeniable. It always works when applied correctly on a direct fire or coil-pack engine (dizzy's not so much) if there is no other problem besides a mildly flooded situation. Hope this explains what I already explained before, although it will likely be lost in posts that many are unwilling to read because they are convinced it is "an issue" and not just a convergence of conditions.

 

[markjenn]

Re: Very hard starting today

I haven't read all 43 pages of posts here, not even close, but has anyone addressed this issue as to whether the hard start issue comes about if you are one to pull the clutch in when starting a bike. Those of you that rode Suzuki's are use to pulling the clutch in for the starter to engage.

Since the S10 allows starting in neutral (unlike most Suzukis), that's the way the majority of us start the bikes. I think we can presume that most hard starts have been with the bike in neutral. (The 3x it has happened to me have all been with the bike in neutral.) Converse to your hypothesis, would clutching the bike during starting reduce the problem? I don't know, but I doubt it, especially given the large numbers of bikes with the CJM, some of which have had the hard-start problem.

There have been literally tens of hypothesizes proposed for owner-induced things that might be causing the problem (not waiting long enough between key-on and starting for the FI to initialize, wrong grade of fuel, use of kill switch rather than key during last shutdown, whether the bike has CJM or flash, use of aftermarket air filters, etc. etc. etc.) and nothing really has ever made technical sense or has panned out in the sketchy data we have. The only somewhat common denominator seems to be an owner who has interrupted the normal warmup cycle on the previous start, often when moving/washing the bike or sometimes fiddling with the ignition system while installing electrical farkles. But even this is not definitive..... no one has been able to reliably replicate the problem even when aggravating the bike with interrupted start cycles; conversely, several of us have had hard starts with no history of previously interrupted start cycles. The problem is devilishly and classically intermittent.

My theory is that the S10 is wrongly setup to be overly rich at startup (perhaps only in certain ranges of temperature, humidity, etc.) and 99% of the time, it's tolerated and the bike starts fine. But when all other factors break bad (slightly weak battery, slightly fouled plugs, just right weather conditions, etc.) the problem happens and once it does, things go rapidly downhill into a badly flooded condition.

- Mark

 

[autoteach]

Re: Very hard starting today

Thanks for the excellent information. I would hope that you don't normally start your teaching sessions by calling your students "idiots" though. I realise you didn't actually call me an idiot but rather that you think I'm an idiot.

Your opinion of my mental capacity aside, I still believe this is an issue that will eventually be corrected but it won't be if we consider it normal. If it is normal, Yamaha should add a note in the owner's manual so all owners can know the information and not just the relatively small percentage of riders who are members on this forum. My Honda CR125 two stroke certainly has a note in the manual that tells me to go to WOT if I flood it.

I already gave this lesson once, making it the second time. With so many people willing to not follow the lesson, and some of which refute it with conjecture and anecdotal idiocy, I will refer to those people as idiots.


Nothing will be done as it is normal. This bike behaves far better than a supercharged Kawasaki watercraft. Try short running one of those.

 

[Tremor38]

Re: Very hard starting today

Well, not exactly. You may think I am being silly, but I think everyone complaining about a hard start is a total idiot. The fact of the matter is that I have had 1 single start that required throttle application on my super, which I applied after the 3rd or 4th revolution without stopping the cranking cycle and it fired immediately. I have owned a Chevy Blazer, and now own a Subaru Forester. Both have had "hard starts". The blazer left me stranded many times because of it, the Subaru has not. I feel that the distributor played a role in the blazer's problems and the inability to resolve them. Now, how does WOT affect an engine:

It has been talked about many times, but I will cover it again in depth.

WOT on a carburetor engine decreases velocity through the carb's venturi, decreasing the vacuum that the air makes and thereby drawing less to no fuel in to the motor.

WOT on a FI engine is programming that has been put in the computer to provide a method of clearing a flood. this exists for the situation that everyone may encounter when short running a vehicle, or when parameters and situations have led to a hard start. Why can't the computer figure this out? Well, there are a few inputs that help the computer logic sort out exactly how much fuel to inject per cycle. Those include MAP, TPS, IAT, ECT, MAF (if the vehicle has it), BARO, CKPS, and O2S. The MAP sensor gives pressure of the intake, TPS the throttle position, IAT the intake temp, ECT the coolant temp, MAF the air flow in grams/s, BARO the barometric pressure (for relation to the MAP, to give delta), CKPS the crank speed, and the O2S the oxygen level in the exhaust. The only feedback is the O2S, and it can only read when properly heated. It also is a dumb sensor, like most of these they cannot see problems. For example, the oxygen level in the exhaust is rather high during a misfire or when cranking and not firing. this is because the oxygen is not consumed in the chemical reaction conversion of fuel. So, if it used this info what would it do? It would add more fuel to a situation that doesn't require it because the conditions that are present are a result of the occurrence and are not the occurrence itself. So, how do you program around this? You tell it to ignore O2 at cranking (and, it measures oxygen, not fuel, so it cannot measure afr anyway at startup), and you tell it to not do a full scale enrichment if the high oxygen levels coincide with a misfire that didn't have fuel trim out of specifications leading up to the misfire event. Are there conditions that are outside these conditions? Yes, you better believe it. But they do their very best to minimize that by testing in different areas with different conditions (Arizona vs Alaska, Florida vs Colorado).


As for how WOT affects both:
If you have ever done a compression test on a vehicle, you know that it is spec'd for WOT. This is because the pumping losses with the throttle closed is so high (no air to compress). Essentially, one of the benefits of starting with the throttle open is that you get more compression and big gulps of air. It is also one of the drawbacks, also noticed when kick starting large singles or twins or with bikes that have weak starting systems.


So, sticky this. It is the facts, and they are undeniable. It always works when applied correctly on a direct fire or coil-pack engine (dizzy's not so much) if there is no other problem besides a mildly flooded situation. Hope this explains what I already explained before, although it will likely be lost in posts that many are unwilling to read because they are convinced it is "an issue" and not just a convergence of conditions.

Well, since you have listed a myriad of conditions that leaves any motorcycle with unavoidable hard starts, Yamaha should just rest on its laurels, even though Honda manages to build bikes that are near-flawless at starting under normal conditions (a stalled, already warm engine being the possible exception). You continue in a condescending manner about how WOT is our savior, which is correct most of the time. Oh, by the way, at that crankshaft speed on this bike, your twist grip might be at the stop, but the TB is at less than 10 percent open...It does help the bike start, but technically it is not 'WOT.' While we are talking about servo-controlled throttle bodies and the virtues of increasing the throttle opening to help an overly-rich engine start, it seems like a straight forward algorithm to have the ECU crack the TB open if an engine speed increase above cranking RPM doesn't occur within a specified period. Once an acceleration occurs, the ECU can immediately close the TB. That's just one idea, and I'm sure Yamaha could come up with something better, but my guess is this comes down to $$ that they would rather not spend on an issue (yes, I said issue) that is not safety related.

Putting a simple note in the owners manual would be more cost effective I suppose. After all "idiots," whom I gather from you are people who are not engine fuel systems experts, don't have the inside of the visor to read on a motorcycle. ::008::