Grey wire mod linked to engine smoking???

[steve lemley]

I have a 99 WR400. The carb has had the stopper ground down to YZ specs, the exhaust cam has been turned one tooth forward to the YZ specs and the stock exhaust has all the baffling removed and a large end cap inserted. Here is my problem. Since i baught the bike it has ran absolutely perfect in all altitudes. The only mod I could see that wasent done was the "Grey wire" mod. So I did it and ever since it runs good after warm up but now is smoking very white out of the tail pipe until warm and hard to start in the morning. This last weekend was the worst. I had to use the hot start in the morning to get it to fire and it took probley 20 or so kicks. It usually takes 2 or 3 at most. My big question is can the "grey wire" mod effect the way the bike is jetted or what the heck is going on that smoke scares me when its warming up in the morning??? Thanks in advanve to the gods!!! ??

P.S. giving my bikes mods, can someone recommend a good jetting setting... Thanks...

[eldrapo]

Is your coolant low? is der nofreeze going out the exhaust?

[Numskull]

From my research, the grey wire changes the ignition timing to that of a yz. Some people have said that its in conjunction with the throttle stop mod, but I disagree with that. I believe the grey wire mod to be timing related(it will advance the ignition timing) to coincide with the cam timing being advanced to the yz specs.

That being said, I would not think it should cause white smoke. White smoke is cause from water burning(steam). I would say you have a blown motor, or it could be that the jet stream is down in the gulf of Mexico making it colder than **** out side, thus causing condensation in the exhaust. If it quits smoking after it warms up, that is most likely what is happening.

[steve lemley]

come to think of it. It was abnormally cold and damp that morning. It had snowed and rained that night which doesent happen very often in So. Cal. Maybe its just picky on the weather and it was just condensation in the cylinder that formed overnight? It runs so good I hate to think anything could be wrong. Any other ideas guys... Thanks.

[dbailey223]

Numskull, from what I have read here, I don't think your conclusions about the grey wire are accurate, but I could be wrong. I'm just going off of what I recall reading. Most say here that doing the grey wire goes along with doing the throttle stop screw, and that it is not tied in with the cam timing.

[clark4131]

Bailey is correct. The grey wire has little to do with changing the exhaust cam for "YZ Timing". The grey wire mod changes the ignition mapping to that of the YZ which is then able to handle the increased fuel delivery due to the shortened throttle stop. With the WR throttle stop, the main jet is barely engaged, thereby eliminating the need for the YZ mapping. Once things are "free modded" the bike needs the YZ mapping to function properly due to the increased fuel and air the bike is getting. Replacing the WR exhaust cam with a YZ version does also need the Grey Wire mod, but by the time you're there, you've already shortened the throttle stop or else you are bass-ackward and should be riding a quad instead. It's a muliti-level process:

Level 1: Stock WR = EPA dog

Level 2: Throttle Stop & Grey Wire = Proper WR

Level 3: Throttle Stop, Grey Wire, YZ Cam = E-Start, 5-Speed YZ Conversion

Level 4: Sell the WR and just buy the damn YZ 'cuz that's what you really wanted anyway ?

Clear as mud now?...SC

[steve lemley]

Back to the original question, Is the smoke and rough starts related guys??? if not, what could start causing this condition?

[bg10459]

White smoke sure sounds like a blown head gasket, although if it gets better as it warms up, it could also be something cracked (as the metal heats and expands, it seals the crack). I doubt it's from condensation burning off. Check your coolant level and do a compression test / leakdown test.

[Numskull]

Let us know how its running now that it warmed up outside. Jetting is critical on these bikes according to temperature, just look at indys chart that is stickied at the top of this forum. 10 degrees makes a difference. Your hard starting and white smoke could have been caused by the cold temperatures.

Now to argue with with BG and Clark ? First off about the condensation. You start up any motor when its under 35 degrees out and it smokes white. If you have a blown head gasket or cracked head, it will not seal itself up after warming up, it will get worse. ?

About timing. Ignition timing has nothing to do with fuel mixture or how far the throttle is opened. Ignition timing tells the spark plug when to fire. They have a solid state cdi ignition that advances automatically as the rpms increase. It is the rpm's of the motor that controls the timing advance, not the throttle position. The more rpm's that the motor turns, the more the timing advances BFTDC. It is this way so that preignition and detonation dont blow a hole in your piston. Now that we understand what ignition timing is, lets talk alittle about cam timing. The wr comes out with cam timing slightly retarded for more controllable power. So in essence the intake valve opens a little later, and the exhaust valve closes a little later. After advancing the cam timing to yz specs, it would only make sense to adjust the ignition timing(cut Grey wire) to yz specs.

Of course these are my opinions and in no way will I bet $100 that im right, but It will take some convincing for me to change my opinion

[steve lemley]

Thanks for the breakdown numskull. By the way, it was about 29 degrees that morning and even with the decomp. lever puled in, when I kicked it over probley 20 times to clear it out, it was blowing white rings (of condinsation) it seems. Theres no way that there was that much "smoke" left in the cylinder after 20 kicks solid with the decomp. lever in. It's all starting to make cents now. Thanks everybody...

[bg10459]

OK Numskull, Steve, Please read the following info in regard to the grey wire. While you're at it, read the rest of the FAQ in the WR250 forum as it generally applies to the 450's as well. It's a wealth of knowledge that all WR owners should read.

http://www.thumperfaq.com/gray_wire.htm

Now, if your bike is blowing white smoke for more than 10 seconds, I'll bet it's not condensation. How much condensation do you think is in the cylinder? Condensation will only form when you have big temperature swings. The warmer the air, the more moisture it will retain, so if the air in your cylinder is cooled, moisture will be released in the form of condensation. If the temp hasn't changed, the air is still capable of holding the same amount of moisture and you will get no condensation.

As far as a crack sealing itself with an increase in temperature, if it's small enough it may, at least to the point of reducing the visible amount of steam.

[99wr400]

I have a 99 WR400. The carb has had the stopper ground down to YZ specs, the exhaust cam has been turned one tooth forward to the YZ specs and the stock exhaust has all the baffling removed and a large end cap inserted. Here is my problem. Since i baught the bike it has ran absolutely perfect in all altitudes. The only mod I could see that wasent done was the "Grey wire" mod. So I did it and ever since it runs good after warm up but now is smoking very white out of the tail pipe until warm and hard to start in the morning. This last weekend was the worst. I had to use the hot start in the morning to get it to fire and it took probley 20 or so kicks. It usually takes 2 or 3 at most. My big question is can the "grey wire" mod effect the way the bike is jetted or what the heck is going on that smoke scares me when its warming up in the morning??? Thanks in advanve to the gods!!! ??

P.S. giving my bikes mods, can someone recommend a good jetting setting... Thanks...

The exhaust cam is supposed to be RETARDED 1 tooth, not advanced, for YZF timing. You may have worn valve guides and seals if the problem persists. go ride 3-5 more hours, if the bike continues smoking, you're seals/guides are worn out. You may also have a blown head gasket, but it's very unlikely, because steam evaporates very quickly, and wouldn't go much more than 3-4 feet out of the exhaust, smoke tends to stay airborne.

[99wr400]

Let us know how its running now that it warmed up outside. Jetting is critical on these bikes according to temperature, just look at indys chart that is stickied at the top of this forum. 10 degrees makes a difference. Your hard starting and white smoke could have been caused by the cold temperatures.

Now to argue with with BG and Clark ? First off about the condensation. You start up any motor when its under 35 degrees out and it smokes white. If you have a blown head gasket or cracked head, it will not seal itself up after warming up, it will get worse. ?

About timing. Ignition timing has nothing to do with fuel mixture or how far the throttle is opened. Ignition timing tells the spark plug when to fire. They have a solid state cdi ignition that advances automatically as the rpms increase. It is the rpm's of the motor that controls the timing advance, not the throttle position. The more rpm's that the motor turns, the more the timing advances BFTDC. It is this way so that preignition and detonation dont blow a hole in your piston. Now that we understand what ignition timing is, lets talk alittle about cam timing. The wr comes out with cam timing slightly retarded for more controllable power. So in essence the intake valve opens a little later, and the exhaust valve closes a little later. After advancing the cam timing to yz specs, it would only make sense to adjust the ignition timing(cut Grey wire) to yz specs.

Of course these are my opinions and in no way will I bet $100 that im right, but It will take some convincing for me to change my opinion

I've found that the YZF cam timing actually makes the power smoother. With the WR timing, the bike has an abrupt increase in power from idle to 1/3 throttle, with YZF timing, the bike still has bottom end power, but it is a lot smoother, and pulls harder on top.

[Numskull]

The exhaust cam is supposed to be RETARDED 1 tooth, not advanced, for YZF timing. You may have worn valve guides and seals if the problem persists. go ride 3-5 more hours, if the bike continues smoking, you're seals/guides are worn out. You may also have a blown head gasket, but it's very unlikely, because steam evaporates very quickly, and wouldn't go much more than 3-4 feet out of the exhaust, smoke tends to stay airborne.

Thanks for the correction on retardation of the cam ?

[Numskull]

I've found that the YZF cam timing actually makes the power smoother. With the WR timing, the bike has an abrupt increase in power from idle to 1/3 throttle, with YZF timing, the bike still has bottom end power, but it is a lot smoother, and pulls harder on top.

Hey thanks for the info wr400, I dont have any riding time on my wr426, but the little I do have has been nothing but abrupt power. ? I wasnt gonna give it the yz timing cause this baby already has some serious snap. ?

[Numskull]

Hey steve, let us know how your bike is running. But I think its unanimous here that the grey wire isnt causing it to smoke. You either have a mechanical failure or it smokes white like my chevy did this morning.

And BG10459, I did look at your link and read alot of info there. I did find out that along with RPM'S of a motor, the cdi does take imput from the throttle position. But I would like to say the throttle position has a very minamal effect, has to do with vacum of the motor, compared to the RPM's of the motor. I also found out that the cam timing is more influential on what you would want for ignition timing than vacum timimg. But this thread was for steve so im not gonna post the engineers reports here.

[steve lemley]

Thanks guys, Ill keep you posted I ride every weekend and it should be at least 15 to 30 degrees warmer on Sat. morning. Ill let you know how the dinosaurs temper is in the morning. Thanks again... ?

[steve lemley]

Maybe time for a big bore kit if shes getting worn out ???????

[txaggie929]

I hate to break it to all y'all, but the grey wire mod DOES NOTHING TO THE PERFORMANCE OF THE BIKE! I work at a Yamaha dealership, and we have checked into this. All it changes is the bikes ability to rev in NEUTRAL= no performance gain. Just thought I'd throw it in while we're at it.

[WheelsUp]

I hate to break it to all y'all, but the grey wire mod DOES NOTHING TO THE PERFORMANCE OF THE BIKE! I work at a Yamaha dealership, and we have checked into this. All it changes is the bikes ability to rev in NEUTRAL= no performance gain. Just thought I'd throw it in while we're at it.

???

That's the BLUE wire mod.

The grey wire does indeed affect the ignition (not cam) timing.

With it connected, the ignition timing is retarded by about 30 degrees above 6000rpm.

I agree, the blue wire mod is a waste, especially on the WR which then requires that the clutch safety be bypassed for the e-start to work.