Hot pipes...
04-29-2010, 05:18 AM
#1
Member
Squid
Thread Starter
Join Date: Oct 2008
Location: Baltimore, MD
Posts: 43
Hot pipes...
So I'm curious about this.
I was checking my front air pressure the other pre-dawn morning and noticed that my front exhaust was glowing dull red.
Bike was warmed up, choke on half, idling around 1200, had been running for about 5 minutes.
Bike runs fine, choke off idle is about 9-1100...
Dull red on uncovered pipes means about 800-1000 F.
It's only down to about halfway to the turn aft from the head, maybe 10" of pipe total.
Gonna put an IR thermometer on it to confirm.
Never seen this before in other bikes, but I think chrome would prevent it (glows hotter). So I have no idea how hot the pipe should be.
Any thoughts? Non issue?
Thanks.
M
I was checking my front air pressure the other pre-dawn morning and noticed that my front exhaust was glowing dull red.
Bike was warmed up, choke on half, idling around 1200, had been running for about 5 minutes.
Bike runs fine, choke off idle is about 9-1100...
Dull red on uncovered pipes means about 800-1000 F.
It's only down to about halfway to the turn aft from the head, maybe 10" of pipe total.
Gonna put an IR thermometer on it to confirm.
Never seen this before in other bikes, but I think chrome would prevent it (glows hotter). So I have no idea how hot the pipe should be.
Any thoughts? Non issue?
Thanks.
M
04-29-2010, 05:48 AM
#4
Senior Member
SuperSport
Join Date: Jul 2008
Location: Twin Cities
Posts: 505
I've noticed this a time or two on my SH. It happens nearly anytime I let my 450 idle for more than a few minutes (rev it and it goes away). I see it on MX bikes all the time. I think that has to do with the fact that many have titanium headers. Anyway, I've never worried about it on any bike.
04-29-2010, 07:21 AM
#5
Senior Member
Superstock
Join Date: Jan 2009
Posts: 267
I've noticed this a time or two on my SH. It happens nearly anytime I let my 450 idle for more than a few minutes (rev it and it goes away). I see it on MX bikes all the time. I think that has to do with the fact that many have titanium headers. Anyway, I've never worried about it on any bike.
04-29-2010, 09:17 AM
#7
Senior Member
MotoGP
Join Date: May 2008
Location: San Clemente, CA
Posts: 3,451
You're leaving the choke on too long. Honda says over 30 seconds of choke could cause engine damage. The rich mixture is causing elevated levels of hydrocarbons to exit in the exhaust. And especially if you have the PAIR, it then burns in the exhaust. And set your idle up to 1300 or 1400 rpm warm. That should help your warm-up with the choke off after 30 seconds. You may need to hold the throttle for a minute, but that's better than washing the oil off your cylinder walls.
On carbureted cars I've seen catalytic converters glowing cherry red when the choke was not "kicked down" after starting a cold engine. This would happen after about 5 minutes while running at fast idle.
On carbureted cars I've seen catalytic converters glowing cherry red when the choke was not "kicked down" after starting a cold engine. This would happen after about 5 minutes while running at fast idle.
04-29-2010, 11:00 AM
#8
Senior Member
Back Marker
Join Date: Apr 2010
Location: Upstate NY
Posts: 115
^+1
I just got my Haynes manual and it said something to that effect as well. The times I've started mine up it needed about 10 seconds of choke and then ran beautifully. 5 min of choke is quite a long time...for anything.
I just got my Haynes manual and it said something to that effect as well. The times I've started mine up it needed about 10 seconds of choke and then ran beautifully. 5 min of choke is quite a long time...for anything.
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