how to get the engine to start faster

[MANIAC998]

This mod has definately got my attention. I'm running an '06, and time willing, I'll try this mod tomorrow. I'll warm the engine up first, and then do a normal start with the wire connected. Then step two will be minutes later with the wire removed. Then, just as a control, I'll re-attach the wire and do a third start. And after rereading this thread, I think I'll try a fourth test also. The fourth test will be with the wire connected and the spark plug removed. If it makes two revolutions before sparking, then there will be a fifth test. Fifth being with the wire disconnected. I will report my findings as soon as I get the test done.

Maniac

Edited January 21, 2011 by MANIAC998
Addition

[MANIAC998]

Alright, I got a chance to try this mod out yesterday, and here are my findings.

Test 1- Wire connected. Result: Approximately two revolutions before engine fired.

Test 2- Wire disconnected. Result: Nearly instantaneous start of engine

Test 3- Reattached wire. Result: Approximately two revolutions before engine fired.

These results led me to try another test, where I try to find out if there is actually a so-called "Dead Spark" on the first two revolutions of engine turn-over using the electric start button with the wire connected. Here is how I tested for this.

I left the sparkplug in the engine and just removed the plugcap. Then I installed a spare plug into the cap. This way, the engine still builds compression, taxing the starter system, as per a normal engine start. Here are my results.

Test 4- Wire connected. Results: Engine makes approximately two revolutions before sparking.

Test 5- Wire disconnected. Results: Spark occurs almost instantly.

These results actually surprised me! So much so, that I felt that too many people would try to discredit my results, so I videotaped the last two tests (Test 4 & Test 5). I don't know how to post a video, so if it's needed, someone will have to tell me how. Hope this helps encourage others to try this mod. Just not anyone racing in Montana!!! Maniac

[BigBanger]

The question is why is it that the CDI only fires on the third stroke with the button? Why did yamaha desighn it like that? there must be a reason for this ?

Anyone with info?

I'm sure its to allow the motor to spin up before introducting a spark (ok its my guess) I have done this mod and love it but on one occasion I hit the start button and the motor briefly turned before locking up a bit like a hydraulic lock

I relased the start button and tried again and it fired instantly. This could also be due to the fact I have a smaller battery and it was a cold start but it never happened before I did the mod.

[William1]

Sorry it took so long for me to get back to you Guy. Being my WR always starts instantaneously (except when it is colder than a thing) and the Sky Blue wire made no difference to me, I was skeptical, as my previous posts oozed of.

Well, I got off my butt... again, and went and did the mod to my WR250. It does seem to start faster. I traced the wiring diagrams as you told me to Guy and I understand the interface. I also discovered that is the pin touches ground, the starter motor will spin!

So I apologize for my previous bald faced lies!

Next question (at least for me) is why did/would Yamaha do this? Is it to give the engine a chance to suck some fuel in the carb passages ways before attempting to fire off? This seems plausible until you wonder if that is the goal, then why even bother to kill the spark, just let the engine crank until the gods of good fuel mixture give their blessing and go. Is there a perceived issue of backfiring? Is there a desire for the engine to have some momentum until the spark potentially kicks back?

Here is a picture of the plug and the wire removed and sealed. You will notice it was right next to the infamous Gray wire (mine is on a switch, that is why the wire is still there) on my wr250. I have a few extra blank plugs for the socket so I put one here the wire was and used a second one to cap off the other end of the shrink wrap.

.

[William1]

..............So much so, that I felt that too many people would try to discredit my results, so I videotaped the last two tests (Test 4 & Test 5). I don't know how to post a video, so if it's needed, someone will have to tell me how. Hope this helps encourage others to try this mod. Just not anyone racing in Montana!!! Maniac

If you post the video on YouTube and give me the URL in a post, I'll fix it so it shows here.

[the_smoo]

i have also been watching this thread, and from the evidence given it does look like it works..

but as an Engineer, I am more interested in why it would have been designed this way.. also what are the implications of leaving it disconnected long term?

I know earlier in the post someone mentioned it made no difference to their bike after a few years of having it removed.

going to dig out the wiring diagram..

[the_smoo]

kind of hard to work out exactly what is going on with the starting circuit from the diagram alone..

the blue wire with the white line is listed as L/W according to yamaha wiring codes.

http://www.weeksmotorcycle.com/yamaha-wiring-diagram.html

This changes to L/B which is blue with a black tracer and goes back to connect below the starter relay diode, starting circuit cut-off relay and the base of the starter relay.

If I had to guess, I would say that the starting circuit cut-off relay is introducing the delay which in turn is sensed by the CDI. Reason I say that, is because there is a small resistor across the coil of this relay which would cause a delay in the contact connected to the battery from opening. This wire from this relay goes straight to the CDI via the wire in question.

So in short.. not exactly sure how the circuit works, but fairly certain it wont cause any damage if left disconnected, as I cant see how it impacts anything accept the starting circuit..

(08 model)

Edited January 22, 2011 by the_smoo
including year model.

[the_smoo]

circuit diagram for ref highlighting the wire in question

http://img703.imageshack.us/img703/3446/001mod.jpg

http://img822.imageshack.us/img822/5732/002hq.jpg

[the_smoo]

curiousity got the better of me.. pulled the cover off, removed the wire and sure enough... it starts quicker without a doubt.

and its about 30F out!

[MANIAC998]

My guess as to why Yamaha did this, would be to point out the troubles they incurred on there first electric start model back in 2003. They were having all kinds of troubles with the machine shearing keys on the flywheel, among other things. So I believe they installed this to help lessen the possibility of it happening on any electric start model that they produced. That's my guess, and I'm sticking to it!!! Maniac

[William1]

My guess as to why Yamaha did this, would be to point out the troubles they incurred on there first electric start model back in 2003. They were having all kinds of troubles with the machine shearing keys on the flywheel, among other things. So I believe they installed this to help lessen the possibility of it happening on any electric start model that they produced. That's my guess, and I'm sticking to it!!! Maniac

I was suspecting the same, they got gun shy. A few extra cranking revs was no skin off their back!

[123BigcoopDawg576]

Lol funny how everyone tried this over the weekend ?

I did as well and sure as crap it dang near starts just looking at the button. I did notice that if the piston wasnt at the ideal position it would some time need a few extra spins to start.

I also noticed the bike some times likes a hair of throttle...but then again, it always has with the e-start.

Either way, Im happy with this mod!?

[MANIAC998]

Yeah, thanks to Climax for starting this thread, and also to TribalBC for pointing us in the right direction! But lets try and keep this a secret from anyone racing in Montana, alright?! Maniac:thumbsup:

[climaxx dirtbikes]

Thanks for the credit but I have yet to try this on my bike. Great find TTer's

[climaxx dirtbikes]

Did the wire mod tonight and it does start faster! Although I am having some other issues with the bike.

[travertt]

My guess as to why Yamaha did this, would be to point out the troubles they incurred on there first electric start model back in 2003. They were having all kinds of troubles with the machine shearing keys on the flywheel, among other things. So I believe they installed this to help lessen the possibility of it happening on any electric start model that they produced. That's my guess, and I'm sticking to it!!! Maniac

If your theory of why Yamaha put a firing delay on the e-start is because of the troubles they had on the '03 model year (this does make a certain amount of sense)..maybe someone with an '03 can check out their bike to see if it has the aformentioned "blue/white wire" on it......and if it does, what happens when it is disconnected.

If there is no "blue/white" wire on the '03, then it certainly looks like the theory is correct....that the wire was introduced in '04 to correct the starter problems. There is however one problem with this theory...if the "blue/white" wire was introduced to correct this serious problem...are we not all putting our bikes at risk of having this same serious problem if we disconnect the wire??

If there is a "blue/white" wire on the '03, then it appears that is not the reason and it would be interesting to see what happens when the wire is disconnected....ie will an '03 be quicker on the e-start with the wire disconnected just like the newer models.

Just a thought.

[grayracer513]

Whether the delay was built into the '03 or not, the purpose is to reduce the likelihood of the engine kicking back against the starter by preventing it from starting on the first (and perhaps second) compression stroke that occurs. This assures that the crank will have a minimum of two full revolutions to build inertia before it fires.

The starter clutch also includes a torque limiter which slips if the built-in maximum load is exceeded, and that, I believe, was what was added to the '03 starter.

[travertt]

Whether the delay was built into the '03 or not, the purpose is to reduce the likelihood of the engine kicking back against the starter by preventing it from starting on the first (and perhaps second) compression stroke that occurs.

Yes I'm sure the above is true...the issue I was trying to raise is the following....

If the solution to the "03 problem was the introduction of the "blue/white wire" circuit in order to delay ignition for the first compression stroke or two (which appears to be the case)....are we then putting our bikes at risk of

re-introducing the potentially catastrophic '03 problem if we disconnect that circuit??

I have an '04 WR450 and ride with two friends, one with an '06 KTM400 EXC and the other with an '09 Husky 450. Both their bikes start much quicker with the e-start than mine does regardless of weather or whether the engine is hot, warm, cool or cold.

I would love to have my old WR "spring to life" like their bikes but not at the cost of being at risk of the well documented "03 problem. Just wondering if there was a way to determine whether or not I (we) would become "at risk" by implementing this mod or not.

I figured that if we could determine that the '03 did not have the blue/white wire...but that all subsequent bikes do have it...then it would tend to prove that the blue/white wire was Yamaha's "fix" for the problem and therefore that perhaps its a bit risky to disable it.

[grayracer513]

According to the service manual for the '03 model, the CDI wiring is identical to the subsequent years, and does include the blue/white lead at the CDI connector that ties to the starter relay circuit.

[travertt]

Sorry

I guess this wasn't the world's smartest question/concern. If I'd thought about it a little longer I could have figured out for myself by looking at the appropriate diagrams that the '03 wiring showed the same circuitry. ?

On the other hand I guess this indicates that the ignition delay associated with the e-start and the blue/white wire was not just a Yamaha response to the problems with the '03 but are likely just inherent in Yamaha's engineering approach to this product. Still makes you wonder why no other manufacturer seems to feel the need for this approach.

On the up side....I can now safely make my bike start better (hopefully).