[TW_in_BC]

I've been having a hard time starting my TW lately. Cold or hot, it didn't make much difference, she was just really tough to start.

Then, I remembered something that I noticed a few weeks back when I replaced my stator coil. When I crank her over, there doesn't seem to be much spark while cranking, but as soon as I let go of the switch, she sparks nicely!

So, rather than crank and crank and crank, I just give her a brief little "blip" of the starter, and away she goes now...Hot or cold!



While I don't mind this new method, I have to wonder why it is that the spark doesn't show up until AFTER I've released the starter button. She WILL start if I crank her repeatedly, but it takes a while. By giving her a quick blip, she starts almost instantly.



- New spark plug

- fairly new battery < 6months

- good gas (with Seafoam treatment)

- anybody who's replaced their stator knows that it can only go in ONE WAY...



Anybody got any ideas? What's up with the spark thing; shouldn't it make sparks WHILE I'M CRANKING, instead of after I release the button?

When she's going, she runs like a top with no hesitation or sputtering at all, even at high RPMS.

 

[bluedevilfootballman]

when you crank the motor your battery is using most of it's juice on to turn the starter rather than to send fire to the plug. i'd say holding the starter for a shorter amount of time uses less battery then laying on it which causes it to send more juice to the cdi and throw a better spark. if your bike is equipped with a kickstarter i'd bet kicking it would make it fireup even faster.

 

[TW_in_BC]

Thing is, I used to be able to crank it over a few times and have it fire right up. Now, it doesn't seem to want to fire until I stop cranking...strange!



Unfortunately I don't have a kick-start or I would be using that exclusively!

 

[jbfla]

TW_in_BC,



I wish I had an answer. My TW (2005) is in pretty good shape maintenance and mechanical wise.



It acts like yours. Crank and crank and it eventually starts. Tap the starter button and it fires up right away.



When I remove the spark plug, ground it to the engine, and crank there is a pretty weak looking spark. Not a strong, bright blue one, like on my other bikes.



I seem to remember it used to start up quickly when holding down the starter button.



Hopefully someone more knowledgeable in electrics will have an answer.



jb

 

[peruano]

My 2 cents worth would ride with Tanner. If the starter is drawing down the battery, there is less voltage for the bike's spark. The cause could be a weakened battery or a starter that is sufficiently worn to draw more current than it did in its previously pristine condition. I know my TW starts hard if I try to do it while in gear but with the clutch lever compressed than it does if I am in neutral (clutch lever either position). I'm guess that my motor is just that much harder to turn over when only disengaged with the clutch than with bike in neutral, but whether this is affecting spark or just turnover rpms I can't speak to.

The easiest thing would be to check the voltage on your batteries. If its lower than optimal, thats probably your problem. Smarter people than me could check the amp draw on your starter (with a multimeter) and probably diagnosis or eliminate potential starter deficiencies. Good luck. Tom

 

[lizrdbrth]

Very likely this is caused by the starter relay, rather than the starter itself.



Those of you with older bikes can diagnose this fairly simply. If the bike will start quickly when you kick it, but not when you use the button, this is one of the possible culprits. Another tipoff is if the headlight dims to an orange glow when you crank the starter. The majority of your battery's power is being used to form that arc inside the relay. The longer yer on the button, the bigger the arc.



The points wear and oxidize, and the coils break down over time and if you were to check your starter's amperage draw you would get a false reading and blame the starter, when in fact the relay is arcing.



Pre-'01 bikes had far better relays than later bikes, and almost any other relay from any other bike made is better than the ones our bikes come with. If the relay turns out to be your problem, get the one for the older bike or one from a bigger bike. I run a KLR650 relay in mine.



As Peruano said, a bad cell in a battery could cause a similar problem, as well as loose or corroded cables at either the battery, starter or solenoid. If you're absolutely sure these items are ok you should look at the relay.

 

[arrowsmith]

I can not tell you why it starts that way but the only thing the battery has to do with starting is to turn the engine. The ignition is a separate system and will work without a battery if you can turn over the engine fast enough.

I have another one for you.

My 03 will not start in neutral with the kickstand down but will run in neutral with the stand down.

 

[lizrdbrth]

I can not tell you why it starts that way but the only thing the battery has to do with starting is to turn the engine. The ignition is a separate system and will work without a battery if you can turn over the engine fast enough.

This will only occur when using the starter.



If you don't buy that, try jumping your solenoid across the two large terminals. This simulates a heathy solenoid, and you'll get a normal, fat spark.

 

[arrowsmith]

This will only occur when using the starter.



If you don't buy that, try jumping your solenoid across the two large terminals. This simulates a heathy solenoid, and you'll get a normal, fat spark.

Sorry but your starter and solenoid are not in any way connected to your spark execpt they turn the flywheel which has magnets that passes the coils for the ignition. The only reason you would get a fater spark would be if the motor turns faster.



I have a 91 with a kick starter and no battery and it startes fine.

A TW ignition does not need a battery.

 

[qwerty]

An old, weak battery will crank and crank, but not spin the crank fast enough for the ignition to develop a hot spark. A weak battery can causing starting problems even though there is no electrical connection between the battery and ignition.

 

[lizrdbrth]

I need to quit posting on 2 hours' sleep, I reckon.



Regardless of cause, the net effect is a slower cranking rpm, even if it isn't audible.



In which case your leg will generate more initial crank speed than the starter. All the stars only need to line up once for your bike to start.

 

[owtcast]

I'm with Arrowsmith on this one. If the battery has enough juice to crank the engine over and over for periods of time, it's spinning fast enough to generate spark on the first few rounds. I'd be checking grounds and terminals for corrosion and secure connections. Then if none of those pan out, I'd be looking at the coil and cdi. It is possible to have a brand new one be faulty. If you look on page 7-5 in the Yamaha service manual you will see ALL the components in the ignition circuit. 1. CDI magneto, 2. CDI unit, 3. Ignition coil , 4. Sparkplug, 5.Battery 6. Fuse, 7. Main switch, 8.Neutral switch, 9. Ignition circuit cut-off relay, 10. Sidestand switch, 11. "Engine stop" switch

Out of those, ONLY THE CDI, COIL, MAGNETO, and SPARKPLUG with their adjacent wiring are required for ANY engine to produce ignition spark. The rest of that is safety add ons or for charging the battery.

You really need a SERVICE manual (not owner's manual) to do this troubleshooting for all the resistance values for the components. Electrical troublshooting can be a headache but, it can be done. The manual will really be an asset in breaking down the steps. Without the bike, I'm not sure there's much more I can do. Remember, you can do a lot of troubleshooting WITHOUT spending money.



I gotta ask though since this is sort of odd symptoms. Are you sure the spark is weak? What makes you say so? And, if it's firing up with just a little blip, why would you want to keep cranking on it? And if you are continuing to crank on it, are you sure that you aren't keeping it from starting by dragging it down with the starter? Could it be that you were accustomed to having to crank repetitively with the old CDI and now that it's a new one, it's firing up with the first blip?

Please don't take my questions as an insult. But without knowing you, I have no way of knowing your mechanical abilities. Keep us posted on how it goes. Good luck.

 

[lizrdbrth]

CDI at lower-than optimum cranking speeds is like filling a bathtub with the drain open.



You'll fill the tub eventually, but only if the flow of the faucet is greater than the amount going down the drain.



The reason your spark increases when you let go of the button is because your crank trigger can't operate at such a low speed, which allows some buildup until it can.



Think I'll go start an oil thread.

 

[PJungnitsch]

The standard spark on these is pretty weak, I know I've tried to test spark strength with a gap tool and found it impossible to see in daylight.



Found here that CDI ignition is not considered a good starting type, its strengths are high rpm operation:



As we'll see, CDI is a different animal. Here the voltage rise time is a short 6 microseconds, but the spark duration is shortened considerably also. The quick charge time is an advantage in high RPM settings but the short spark length is a disadvantage for starting and other high rpm compression/ratio fuel/mix situations. Because of this, the longer duration of inductive discharge systems is sometimes preferred over CDI.



http://www.jetav8r.com/Vision/Ignition/CDI.html



Learn something new everyday.

 

[qwerty]

Remove the battery from the bike. Hook jumper cables from a car or truck to the battery cables on the bike. If that solves the problem, the problem is the battery.



Do not hook jumper cables form a car to a motorcycle battery. A car battery can dump so many amps so fast it could cause the bike battery to boil over or explode. The bike does not care how much overkill a battery is, but a bike battery does.

 

[owtcast]

Some of the responses here crack me up.

 

[jbfla]

...I gotta ask though since this is sort of odd symptoms. Are you sure the spark is weak? What makes you say so? ...

Owtcast, I appreciate any help I can get.



I have the same symptoms as TW-in-BC. I can't speak for him, but my spark "appears" to be weak, as I don't have any way to measure it.



As mentioned, I removed the the spark plug, grounded it to the engine, and cranked. The spark was barely visible.



When I do this on my other bikes, I see a strong, bright blue spark across the plug gap.



The condition isn't a problem because the TW still starts and runs good. I was curious, as I suspect TW_in_BC is, if this is a sign of future ignition problems.



My AGM battery is coming up on being 4 years old, so I will try Qwerty's suggestion.



And as much as I hate to, I will also RTFM.

I was hoping someone had run into this problem before.



Thanks for your, and others, responses.



jb

 

[qwerty]

I just switched to an AGM battery because Tdub would crank and crank and not start. Problem solved.

 

[TW_in_BC]

"I gotta ask though since this is sort of odd symptoms. Are you sure the spark is weak? What makes you say so? And, if it's firing up with just a little blip, why would you want to keep cranking on it? And if you are continuing to crank on it, are you sure that you aren't keeping it from starting by dragging it down with the starter? Could it be that you were accustomed to having to crank repetitively with the old CDI and now that it's a new one, it's firing up with the first blip? Please don't take my questions as an insult. But without knowing you, I have no way of knowing your mechanical abilities. Keep us posted on how it goes. Good luck."



OK, after reading some of the responses, I think I'll just repeat a few points:

The battery was purchased this summer, so it is less than 6 months old; she has enough power in her to crank the engine over for more than 30 seconds, so I think it's safe to assume that there's enough "juice" to create a spark, or to turn the magneto fast enough to create one.

The spark appears "weak" because if I ground the plug to the engine, the spark is barely visible WHILE CRANKING, but appears nice and strong as soon as I release the starter button.



Why do I keep cranking on it? Well, I don't anymore, now that I've discovered that I can start it with just a blip. I didn't replace the CDI, just the stator coil assembly.

When the original problem first showed up (complete lack of spark) I followed the Manual's troubleshooting guide and found the culprit to be the source coil. I've taken resistance readings off of pretty well every strand of wire on the bike and the source coil was the only problem at the time. Thanks to all for the suggestions, this continues to be a strange problem...she runs like a top once she's going!

 

[heyduke]

This may be a little late in the game but I was reading this post and realized another post might provide some insight to this post that might be worth keeping in mind for future reference.



There is a post about sputtering on wash board. The problem there rests with the volatge required by the ignittion system processor through the safety switches particularly the clutch safety switch. If the brain does not sense exactly the right voltage then it cuts out and wont allow the engine to run. While running on washboard the vibrations cause intermittent contact through the clutch safety switch resulting in decreased voltage and the engine sputters or stops.



I'm wondering if while cranking with a slightly weak battery there also is not enough voltage supplied to the system but at the instant the starter is disengaged the volatage spikes and it fires.



I to had a weak battery and was haveing trouble with starting by the starter but it fired right up when kick started not a big deal if you have a kick starter but if you don't it would be a pain. a new battery solved the problem and this may offer some insight as to why.