Aftermarket Full Exhaust Bluing

tknj99 · 11-24-2020, 06:51 AM

Hi all
Recently installed the Stonemen Full Exhaust on my Brozz 250 and its running great and a nice bump in power. However ive noticed that the header pipe section went from stainless color to golden color and now has started bluing mostly before and after the bulge section. Is this normal?
Ive read it could indicate high temps due to running lean but ive already added 1 washer to the needle jet and raised the main from 105 to 115 and power wise have no issues from idle to full throttle.. I'm hesitant to add another washer to the needle or increase the main especially if it makes it too rich and robs power.
If its expected then that's fine and I'm looking into reusing the stock heat shield to clamp onto the header section to make it look better.
Thanks for any help

**JerryHawk250** · 11-24-2020, 07:39 AM

It's perfectly normal for them to change color. If the bike is running good i wouldn't mess with it. A 115 is just about right.

TxTaoRider · 11-24-2020, 07:52 AM

I think if you go to hmf exhaust website they have information on this. Basically, blue is fine on a single wall aftermarket stainless exhaust. Some people freak out and say it's a sign of being lean... I use a wideband on my bikes and they are all slightly rich, and they all have blue pipes.

Wild Dog · 11-24-2020, 08:03 AM

That's heat discoloration, it's normal.
The only way to really avoid it is not using the motorcycle or if they made a double walled exhaust, but that would increase the weight.

And before someone says something like "ohh the chinese being cheap again".

These are from BMW (found on bmw forums).

Name: Stainless.JPG
Views: 295
Size: 143.7 KB

Name: Stainless.JPG
Views: 295
Size: 143.7 KB

Name: unnamed.jpg
Views: 277
Size: 68.0 KB

tknj99 · 11-24-2020, 08:38 AM

Thanks guys! Appreciate the feedback. In that case I plan to re-use the stock heat shield to clamp on over the exhaust header bulge section with some pipe clamps i have on order. That should clean it up a bit. I will post pics when completed.

tknj99 · 11-25-2020, 02:15 PM

I added the heat shield today with some pipe clamps to clean things up

Megadan · 11-26-2020, 05:07 AM

Right off the head, especially on a curved or bent pipe that close to the port, the pipes are more prone to bluing due to the concentration of heat that builds up at high pressure areas. When you need to really worry is if they blue, and then go back to "white" again.

11-24-2020, 06:51 AM	#1
tknj99 Join Date: Oct 2020 Location: Central VA Posts: 1,259	Aftermarket Full Exhaust Bluing Hi all Recently installed the Stonemen Full Exhaust on my Brozz 250 and its running great and a nice bump in power. However ive noticed that the header pipe section went from stainless color to golden color and now has started bluing mostly before and after the bulge section. Is this normal? Ive read it could indicate high temps due to running lean but ive already added 1 washer to the needle jet and raised the main from 105 to 115 and power wise have no issues from idle to full throttle.. I'm hesitant to add another washer to the needle or increase the main especially if it makes it too rich and robs power. If its expected then that's fine and I'm looking into reusing the stock heat shield to clamp onto the header section to make it look better. Thanks for any help __________________ 2024 Zuma Storm 150 DLX 2019 Beta 430 RRS 2018 VStrom 1000 XT Former China Bikes: Tao DBX1, Brozz 250, CSC RX4, Titan DLX, Templar X
	0

11-24-2020, 07:39 AM	#2
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,593	It's perfectly normal for them to change color. If the bike is running good i wouldn't mess with it. A 115 is just about right. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	1

11-24-2020, 07:52 AM	#3
TxTaoRider Join Date: Oct 2020 Location: Flower Mound Texas Posts: 904	I think if you go to hmf exhaust website they have information on this. Basically, blue is fine on a single wall aftermarket stainless exhaust. Some people freak out and say it's a sign of being lean... I use a wideband on my bikes and they are all slightly rich, and they all have blue pipes. __________________ 2021 Tao Tbr7 - "Lucille" Mods so far- Brozz swingarm, 21" front rim (Bridgestone Tw302 rear/Dunlop D606 front tires), Digital gauge cluster, pz30b pumper carb, after market hand guards, aftermarket brake and clutch levers, round fold away mirrors, Fly handlebars shortened slightly, 13t front sprocket 2009 Q-link Legacy 250 1982 Suzuki GS1100ES - "Jolene"
	2

11-24-2020, 08:38 AM	#5
tknj99 Join Date: Oct 2020 Location: Central VA Posts: 1,259	Thanks guys! Appreciate the feedback. In that case I plan to re-use the stock heat shield to clamp on over the exhaust header bulge section with some pipe clamps i have on order. That should clean it up a bit. I will post pics when completed. __________________ 2024 Zuma Storm 150 DLX 2019 Beta 430 RRS 2018 VStrom 1000 XT Former China Bikes: Tao DBX1, Brozz 250, CSC RX4, Titan DLX, Templar X
	1

11-26-2020, 05:07 AM	#7
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 8,065	Right off the head, especially on a curved or bent pipe that close to the port, the pipes are more prone to bluing due to the concentration of heat that builds up at high pressure areas. When you need to really worry is if they blue, and then go back to "white" again. __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	1

11-24-2020, 08:03 AM	#4
Wild Dog Join Date: Dec 2016 Location: Argentina Posts: 756	That's heat discoloration, it's normal. The only way to really avoid it is not using the motorcycle or if they made a double walled exhaust, but that would increase the weight. And before someone says something like "ohh the chinese being cheap again". These are from BMW (found on bmw forums).
	3