Picked up a YFZ450R today!

[DohcBikes]

Crap, I forgot nearly everything is EFI. But, it still wouldn't hurt to tune it. The fuel map can be set on the lean side for emission purposes as well. I haven't messed with any of the EFI quads, but, a good fuel tuner should be able to correct some of that and give you a little performance gain as well.

Correct what? No, I think yamaha knows what they are doing big dog. I thought atv's were "gravy" for you.... but you forgot they are fuel injected now so I understand.

! watched a 400 pound man rip wheelies on one today. It runs good.

[6speedthumper]

Correct what? No, I think yamaha knows what they are doing big dog. I thought atv's were "gravy" for you.... but you forgot they are fuel injected now so I understand.

! watched a 400 pound man rip wheelies on one today. It runs good.

I'm not saying that Yamaha doesn't know what they are doing. HOWEVER, many ATV manufactures calibrate their machines to run a hair lean to meet emissions standards.

And, what? I'm not allowed to forget things? Please, jog my memory, where have I said atv's are "gravy" for me? Don't be a douche about it, man, I'm getting damn tired of arguing with you over petty crap. I'm not here to argue with people. Of the 3 sites I frequent, this is the only site I have had ANY personality conflicts with, and frankly, I don't really want to be a member of this site if I'm going to be getting into confrontations with people everyday. I'm here to learn anything I don't know, reinforce what I do know, make friends/riding buddies, and be apart of the 3 wheeler community.

I have not had to work on any fuel injected quads or bikes. Where I live, it's mostly older machines, and many people still take their newer machines to the dealer. I also don't take on too many machines because it's hard to fit them into the schedule when we have so many cars to work on. And, once again, another thread is being derailed.

[6speedthumper]

Fox, how's the clutch feel on that orange bullet? I've not gotten to ride one yet.

[Fox250R]

Fox, how's the clutch feel on that orange bullet? I've not gotten to ride one yet.

Well, When you let the clutch out IT GOES!! LOL! Best way I can explain it... I've been dealing with this so called bog that these 450Rs have and dealing with the glowing header also.. You can't let the Clutch out low @ rpms or the bike dies!! You have to really rap on the throttle when you take off in 1st or 2nd gear just to get it going..The dealership I got it from says its normal but Yamaha says its not and they should fix it...

[BOB MARLIN]

I had the bog problem with mine also. But mine is a '09 and has a carb. I would've thought the bog would be a non issue with the fuel injection. Anyhow, one thing with these quads is that they are really plugged up on the intake and exhaust from the factory. Look at the way the air box seals against the seat. I don't know how it gets any air in there. And then look at the diameter of the exhaust where it exits the tail pipe, its about as big as my little finger (at least on the '09 model). I re-jetted and re-jetted to try to fix the bog and the hot pipe and nothing worked. Everyone kept telling me to "unplug this thing", but it is a wife bike and I didn't want to modify it. Finally I broke down and took the air box lid off and cut the little "pea shooter" restriction out of the pipe. It completely got rid of the bog and I swear it added at least 5 H.P. And maybe brought the temps down a little, but it still gets very hot. The quad does not need any throttle feathering to get it going, in fact if your not careful when you take off it will dump you on your butt. One other thing, these things are a pain in the to change a plug. Do your self a favor and switch to an iridium plug and be done with it. They are about $8 but will last for years.

[6speedthumper]

Hahaha I bet it does! I remember seeing the exploded view of that clutch and liked what I saw. Although, for the average rider it may be overkill. Either way, it's a nice "jump" for the production atvs.

I did do some reading on the glowing header, and it seems that even the older models are prone for extreme exhaust temps. Didn't see so much about the header glowing, though. Most people have used header wrap to make it more tolerable. That just sounds like too much heat, especially enough that the header glows all the time (I'm assuming it does?). Best way to find out if "all is well" would be to put it on a chassis dyno, and run a datastream to make sure everything is dialed in and working properly. It could very well be that it is fine, but, if not, the PCM/ECM/ECU can be reflashed. Not like this doesn't happen to automobiles. There have been millions of cars that had drivability problems due to PCM issues, and need reflashing within a year's time of leaving the dealer.

[6speedthumper]

There is a little mod you can do to the accel pump on the carbed models that helps to eliminate some of the bog as well.

[BOB MARLIN]

Ya, its called the zip tie mod. It does very little. I tried it.

[6speedthumper]

Ya, its called the zip tie mod. It does very little. I tried it.

I can believe that. I did it to the FCR I put on my Warrior and I feel little to no difference. There are the Quick Shot adjustable pump covers to tune the accel pump. I have not tried one yet. Haven't tried the PowerBowl either.

[tripledog]

Fox, that is one sweet ride. Enjoy!

[Fox250R]

https://www.youtube.com/watch?v=iI5E...f4estDu2Qe3gKA

Made a quick vid of the Bog and Glowing pipe..

Sometimes when I start it cold the header will glow pink within like 45sec lol!

Its been at the dealership for 3 days now...Hope they figure it out! I bought a Power commander for it but still waiting for that to show up. Been told it will fix all my probs! We will see....

[6speedthumper]

I'm not an expert on the YFZ by any means. However, that to me, does not seam normal. Fuel injected or carbed, for a header to glow that bright shows a lean condition. Sure, a header may have a very faint glow even when the whole setup is properly dialed in. It all depends on the engine and it's level of tune. All engines and setups are different.

It sounds like the idle is a bit high, which can be a sign of a lean condition. The glowing header, heck red hot tamale of a header in your case, is another symptom of a lean condition. Also, that bog seams to be a lean bog. Sounds like it gets too big of a gulp of air, and once the fuel "catches up" it revs out fine. Have you checked for any unmetered air leaks? Made sure that all fasteners are tight?

Very curious to know what the dealer finds. Could be a few different possibilities.

[BOB MARLIN]

The glowing is more or less "normal". The head pipes are real thin so that adds to it. Every one that I have seen does it.

[6speedthumper]

The glowing is more or less "normal". The head pipes are real thin so that adds to it. Every one that I have seen does it.

Wouldn't surprise me that they are thin, to save weight and money. I read that many find an aftermarket exhaust helps to lessen that glow. Thicker wall pipe I'm sure. I just wouldn't be satisfied with it getting cherry red like it does on Fox's.

[Fox250R]

I'm not an expert on the YFZ by any means. However, that to me, does not seam normal. Fuel injected or carbed, for a header to glow that bright shows a lean condition. Sure, a header may have a very faint glow even when the whole setup is properly dialed in. It all depends on the engine and it's level of tune. All engines and setups are different.

It sounds like the idle is a bit high, which can be a sign of a lean condition. The glowing header, heck red hot tamale of a header in your case, is another symptom of a lean condition. Also, that bog seams to be a lean bog. Sounds like it gets too big of a gulp of air, and once the fuel "catches up" it revs out fine. Have you checked for any unmetered air leaks? Made sure that all fasteners are tight?

Very curious to know what the dealer finds. Could be a few different possibilities.

That's exactly what its doing lol!!!
Got it back from the dealer, they basically told me that due to Emissions on these bikes this is how it's going to run off the showroom floor! Rode it around the parking lot for 30sec it died twice.... I'm about ready to ask for my 3 year warranty that I paid $1300 bucks for and tell them to shove it! I just don't get it, Yamaha tells me it's not normal how this YFZ runs and to take it back to the dealer, but the dealer where I bought it from says it is normal WTF??

And to be honest, I'm not sure if I can get my money back for the Warranty.. I'm going to make some calls to Yamaha tomorrow and see what my options are.

Maybe is does just need to be broken in??? I don't even have an hour on it but it's not much to ride when it keeps dying everytime I let the clutch out.....