Red glow of headpipe YFZ450

[RJ450]

Hey everyone,

I was wondering if it's common that after 2 to 3 minutes of running engine of the YFZ the head pipe glows RED, Very Very Hot. Is it normal or is a setting maybe wrong?

I drove a friends honda 450 and its not as hot and red as mine.

I have full slip on curtis sparks on mine.

[the Z Man]

You may want to check your jetting, sounds a little lean.

[H_W]

Originally posted by RJ450
Hey everyone,

I was wondering if it's common that after 2 to 3 minutes of running engine of the YFZ the head pipe glows RED, Very Very Hot. Is it normal or is a setting maybe wrong?

I drove a friends honda 450 and its not as hot and red as mine.

I have full slip on curtis sparks on mine.

Mine did this when I put my Curtis Sparks pipe on, also. I put a bigger pilot jet in the carb and it fixed it. Just wondering, how can you have a "full slip on"? You would either have a full exhaust or a slip on, not both.

[RJ450]

Yeah I Jet it to stage one as described but the red glow and heat appeared even before when I had the original exhaust on, that's why I was wondering if ya'll does the same.

(Full slip on I meant to say complete curtis sparks exhaust)

[Black R/T]

still sounds like you are lean, check your jetting. does it glow from just idling or does it glow when you are riding it?

[f4istunna]

pretty common on the yfz it seems, my raptor was like this also until i bought the controller. My yfz did it stock, then i took the lid off and baffle out fattened up the jetting and never noticed it again.

[atvrider23054]

Originally posted by f4istunna
pretty common on the yfz it seems, my raptor was like this also until i bought the controller. My yfz did it stock, then i took the lid off and baffle out fattened up the jetting and never noticed it again.

I dont think it's too common after 2-3 mintues...;)

[f4istunna]

they come borderline lean out of the box. 2-3 minutes is a little sudden but just sitting there idling it will glow quick. You cant notice as much during the day but at night you'll notice it.

Ive seeen dozens of stock yfz's glowing at idle.

[atvrider23054]

My yfz was lean from the factory too, but I've never seen it turn red from idleing, even at night.

[f4istunna]

consider yourself a lucky one :D

I never noticed it on my raptor until after a few months i dunno why that was the plug always seemed to be a nice tan color but pipes still glowed.

Another thing to check if your jetting is on is air or no circulating in the cooling system. The last time i rebuilt the raptor i forgot to burp the coolant and it would glow red after like 30 seconds i couldnt figure it out at first finally bled the cooling and all was fine.

[RJ450]

Yeah at idle it starts glowing red after 2-3 minutes, as I know you don't get it much on the raptors or the 450r.. it sucks though..

[f4istunna]

ya alot of the 700's do it from the factory. Once you start modding and add a fuel controller it seems to go away

[Jason Hall]

I believe alot of the problem with glowing pipes Is people don't have their carbs tuned correctly, because the throttle slide height Is set to high causeing the engine to run lean at a Idle. The biggest pain with the FCR carb Is the fuel screw Is hard to adjust. Alot of people don't even adjust the fuel screw, they just turn the Idle up. When you do this, you raise the slide. The pilot jet Is a set size, the fuel screw Is how you fine tune the amount of fuel that gets mixed with air and passes under the slide to make the Idle mixture correct. So like I said before, when you turn the Idle up without opening the fuel screw you just let more air Into the engine without giving It more fuel (self Inflicted lean condition). That will make your pipe very red. An aftermarket pipe will most definatly require the fuel screw to be opened up some. Or might require a bigger pilot jet.

I would suggest buying an aftermarket Fuel screw with a easy to adjusted knob on the end. The fuel screw Is accessed from the bottom of the carb In front of the bowl. Turning the screw In (right) will give less fuel, Turning the screw out (left) will give more fuel.

[miken]

If it's glowing at idle it may be that the pilot jet is too small now that you have opened up the exhaust. Sometimes (as said above) you can overcome this by opening the fuel screw and adding more gas, but opening the fuel screw will affect all the circuits, pilot, jet needle position, main jet. Unless it's glowing red at all throttle openings I would avoid opening it much. I think your FCR also has a PAS (pilot air screw)? Similar to fuel screw but controls air. Maybe try to increase the fuel and close the PAS a bit? You may need to up the pilot jet to really fix?
Mike -


http://img.photobucket.com/albums/v211/miken/Jetting.jpg

[Ryan Plaugher]

Ok first off, all the 450 and possibly other quads header glows to a certain point. Just as long the header doesnt turn red within the firs min and the glowing doesnt go past the water pump you will be fine. You can do some fine tuning to get your jetting right on.

[RJ450]

JASON HALL,

Yeah I bought the R&D quickshot pump but it leaks so I took it off.

Aruba is flat no hill higher than 600 feet and I have jet 132 in at the moment it performed well expect in high RPM it loses power. Do you think I need to go bigger? I got 142, 144 and higher.

Also the pilot screw or fuel screw, how many turn back do you recommend.

[Jason Hall]

I can't really tell ya where you should be on you main, because I have no idea what the temp/altitude Is. I run a 175 main with no airbox lid, and a stock 07 450r pipe with the baffle removed, I live In Michigan. 132 sound VERY lean on the main.

If I were jetting your carb, I would jump the main up quite alot. I would then reccommend you back your Idle screw down until It lowers your idle some. Then adjust your fuel screw until you get good Idle speed and good response when you first throttle In. If you turn the fuel screw In to far, It will want to shut off, back It out until you get good Idle and throttle response just off Idle. On my bike I had a problem when first hitting the throttle It would go puttt and shut off Instantly. I slowly richened up my fuel screw until the problem was gone. I have never changed anything to do with the accelerator pump or the air jet. I just tuned mine with the fuel screw and the needle. I have a 02 crf carb on mine though. Yours might be different.