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simicrintz

Exhaust packing-2007 CRF450

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My nephew just picked up an '07 CRF450 and the pipe gets red hot as it exits the engine very quickly.  We are going over some stuff and pulled the muffler cap and do not see any exhaust packing, just the spark arrestor cone.  Not sure that has anything to do with the heat issue and can't find anything online so thought I would ask if anyone here has any input.

Thanks!

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My last couple 450’s (Yamaha and Suzuki) both had the glowing pipe even when brand new. 
They don’t like to sit and idle for long. 

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So you think this is normal, Ken?  Do you think an exhaust wrap would be a good thing or a bad thing?

I know pipes get hot but this happens so fast that I was concerned.  He does notice it at idle and in the technical stuff so maybe it is the "not moving" stuff that is causing it like you suggest.

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A lot of the high performance four strokes have a single wall / thin  head pipe and they run pretty hot at all times, especially at idle.  Glowing headpipes are not an issue.  I'm not a big fan of the exhaust wrap but there are times where it makes sense to run it (I have some on a part of my Husky exhaust that runs near the air box....it causes melting issues).  

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Thanks, Tom!  He wrapped the pipe and I just want to make sure it doesn't do more harm than good, like holding the heat in.  Knowing that this is normal like you and Ken mentioned makes me feel better; that thing was glowing!

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Why wrap it. Honda doesn't wrap it. They know a bit about it. All head pipes on four stroke race bikes get extremely hot, extremely fast. Just leave it as it was designed and ride it.

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58 minutes ago, Oracle said:

Why wrap it. Honda doesn't wrap it. They know a bit about it. All head pipes on four stroke race bikes get extremely hot, extremely fast. Just leave it as it was designed and ride it.

yep...

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They don't wrap it because they are saving money.  Then you burn yourself.  Next the valves fail due to excessive heat.  You try and buy a pipe from an aftermarket company that Honda has an interest in, therefore making more money.  A dealership that Honda owns does all the repair work and they make yet more money.  It is a conspiracy!!!

I'll tell him it is normal and to just ride the bike.

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22 hours ago, simicrintz said:

We are going over some stuff and pulled the muffler cap and do not see any exhaust packing, just the spark arrestor cone. 

Ya,  What about that?  Someone has been lazy and noising up the place.     🤷‍♂️

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Get it ceramic coated inside and out did this on 990 where it got so hot the gas boiled in the tank

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On 12/15/2019 at 7:42 AM, simicrintz said:

Holy crap!  Boiled always or just when sitting for a while?

When running in the desert about 100deg or on single track.

Pretty typical, will do it while lane splitting if not moving fast enough, these bikes are notorious for this kind of thing, that why i did the ceramic coat on the headers in addition to the insulation on the inside of the tanks behind the pipes.

Depending on the material some pipes when wrapped actually get accelerating aging due to the thermal cycling and become brittle. That happened on a few of the early 950's I know of which is why I did not wrap mine and got it coated inside and out instead.

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I’ve boiled fuel on 500exc. Long nasty climb up Malcolm Smith trail the hard way in 100 degree heat. 

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He took it to the shop today to have it looked at; he's pretty concerned.  I wondered if the wrap would hold the heat in as well.

I don't like the sound of boiling fuel, that makes for one hot engine!

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The shop probably put new packing in, but if you want to have more on hand, a new package of packing was left here for give away by a traveling rider. Yours if ya want it. PM me.

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Very cool of you, Ken!  I will check with him and see where he's at with this and PM you if he needs it.  Thank you again; very cool!

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