Hey..

New to this forum and thought that I'd help the little brother out.. I ride a Honda but he just bought a brand new YFZ450 today and when he got it home began running it around his place to get it broken in a bit. After it got a little dark we notice that the header was getting RED hot. Realized that the fan wasn't running at all after we had run it for a while (really pretty easy) just going around the property running through the gears, etc. He and I are thinking that theres something wrong with it and wonder if this new engine got hot enough to damage it? Any one ever seen anything like this on the new YZF450's?

Don

 

If it were I, I sure wouldn't let them just fix the fan and call it good. I would at least do a comp check and check the valves. Is this the new fuel injected one? I realize the fan wasn't working but it sounds like it is running very lean to get a glow in the pipe. Don't let the dealer off easy, make them check the machine over good. I don't know that this is a common problem but there is always a chance that a new part is defective, that is what warrantee is for.
Let us know what they find out.

 

the header on the YFZ 450 will glow a little at night..The fan..May be bad,many people have said they have fan problems on both Raptors and YFZ's..Take it in and have the dealer check it..Also Yamaha's are known to run lean from the dealer check the plug..On both my YZ250 and 450F's the headers glowed like crazy at night..

 

Hey Guys.. Thanks for the reply's - Hotblooded, I'm not sure on the fuel injection, it's an 08 so? I'll let my bro know what you guys think and we will see what happens.. I'll let you know later.

 

08's are not FI..Might need to re-jet the carb, or atleast adjust the fuel-screw

 

I don't have a 450, but on my '07 Raptor 700, the pipe glows red at the engine at night. Maybe I need to rejet, too?

Now that I think about it, just about every 4 stroke I have ever owned made the exhaust glow red at night. I don't think there's any need to worry. As the sun goes down and the temperatures cool off, your machine is going to run a little more lean anyway.

 

The 07 Rappy 700r is fuel injected no carb to rejet [img]i/expressions/face-icon-small-smile.gif[/img] But you are correct in glowing headpipes..I have rode Yamaha four strokes all my life and the head pipe always glows at dusk..But the plug tells the story..here is a plug chart http://www.verrill.com/moto/se...ugs/plugcolorchart.htm If your plug is still way lean,Yamaha can adjust your computer a little..But what most do that ad mods is get a Fuel injection module..I'd say the best one out is the Power Commander 3,but others are fine also..http://www.powercommander.com/...?mk=15&mdl=120&yr=2008

 

<div class="FTQUOTE"><begin quote>Originally posted by: toddmh

The 07 Rappy 700r is fuel injected no carb to rejet [img][/img] [/L]</end quote></div>

Exactly! I'm glad you caught that out because if I have fuel injection, my fuel flow should always perfect in all temperatures and elevations, right? So if my fuel flow is always right and my pipes still glow, then it's normal for the pipes to glow.

 

450's are lean from factory, main jet should be bumped up at the least. fan rarely kicks on unless you are riding very hot. which is probably not the case since you are breaking it in. I would break it in quickly ASAP take is to stealership, let them service it, then ride it like hell and see if anything changes. You want to get it serviced at dealership or it is unlikely they will uphold your warranty since you couldn't prove that it was maintained to Yamaha's specs.
check out www.allthingsmoto.com and look at dogriders forums about jetting.

 

Giesdog and all others... Thanks for the feedback. What we found out is that the heat is normal and that includes the glow... He took it in and the dealer said it was fine, so we rode it and the fan finally did kick in after pulling some hills out at the dunes. We went out Monday and hes' been riding it every night to get it broken in. His think'n is like yours giesdog... Get it broken in and get it back for the tune up and then ride it like hell... Tell you what.. it's a nice ride! Still can't beat my 87 250r though! We raced "a little" and doesn't look like it's going to be as fast or faster. Wondering that it might though once it's broken in and all.