Evening all,
The RGS500 build is nearly done (http://gstwins.com/gsboard/index.php?topic=56569.msg640202). I need to post some pics on my build thread.
Before we get started, I have looked at most of the Glowing Headers threads and still didn't see anything that helped. Even saw a Buddha post about glowing headers on a stock bike but no answer on what the problem was.
While I had the bike stripped I decided to tackle some issues I was having. When I purchased the bike, the :2guns:PO didn't strike me as being very mechanically inclined. The first clue was the oem muffler had been removed and he was running straight pipes to be like his HD comrades. The bike ran decent but not well.
So the first thing I did last fall was install a Jardine full exhaust and a K&N air cleaner. The bike still ran a bit lean so I rejetted. It still gave me issues so I parked for the winter and started working on it.
The things I have done so far:
1. Rejetted carbs.
2. Adjusted valve clearance.
3. Sync'd carbs
4. Installed new exhaust header gaskets
5. All the new fairings......
Due to work, I hadn't been working on it much. The last couple of weeks I've been getting busy working on it again. I pulled the bike out last night to start it and noticed the first couple inches of the headers were glowing a good orange color. IMMEDIATE SHUTOFF! The bike was running great, throttle response was crisp and no hang idle. I'm not feeling or seeing any exhaust leaks at the head/exhaust joint, or anywhere down stream. Bike took about 5 mins to warm up this evening but it still 86 degrees out and probably didn't start glowing until about 15-20 mins into tweaking carb syncs and idle adjustments. The heads weren't overly hot, i could still touch the fins on the intake side of the head for a few seconds.
Current setup:
Intake: K&N Drop-In Air filter
Exhaust: Jardine Full
Carbs: Pilot Jet: 40, Main Jet: 135, Needle Jet: 2 Washers, Pilot Screws: 2 1/2 turns (Factory Pro "Long Boy" screws)
Carb Sync: within 0.5-1 cm/Hg of one another
Valve Clearances: Intake 0.05mm both sides, Exhaust 0.13mm both sides per GSJacks instructions.
Throttle Cable slack: ~5mm
Hot Idle: ~1300 RPM.
Could I really be running that lean on the low end with 40 jets as to cause the headers to glow? I'll open the Pilot Screws up to 3-3.5turns and see what happens. Seems to be consensus on the Rejetting page that K&N Pods with Performance exhaust needs the pilots opened up more.
I didn't think any amount of glowing was acceptable. I've seen headers glow on turbocharged aircraft that I've flown at night. Never on a FI or NA engine though. We run the engines at very rich settings with lots of airflow over the engine during high power settings to keep it cool. I've only had to shut down once due to overheat (High Cylinder Head Temps) and that after 30 minutes of idling on the ground waiting for a string of commercial aircraft to takeoff.
Any suggestions?
Duane
Your jetting is too lean.You should be running at least a 142.5 and probably 145 mains.
running too rich on a motorcycle will cause the headers to glow. The unburnt fuel is burning inside the header causing it to get super hot. This is normal on bikes when you have the choke on for a few minutes. I really didn't notice it on my stock exhaust because it was black. Now with the stainless Jardine it showed pretty red.
I would take Ben2go's advice. You said it did it at idle? Did it have a fan blowing on the motor? Either way, more jetting is in your future.....
I don't know anything about the stock/Jardine exhaust, but usually stock headers are double walled to prevent bluing and heat transfer. Aftermarket headers are usually single walled for a higher flow rate and weight reductions. Maybe that helped to get the pipes to glow?
+2 on too lean
+1 on too rich
I agree that the Jardine headers are fairly thin walled.
Yes on idle is when it does it. I'll enrichen the Pilot screw by 1/2 turn and place a fan in front of motor tonight and see what happens. I didn't think the Main jets would have any effect on the idle mixture. Am I mistaken?
The absolute bare minimum affect. The only way you would notice the mains when at idle is if you had the main jets out of the carbs.
It idles like crap that way- ask me how I know......
Quote from: rdhill on August 02, 2011, 05:23:36 AM
+2 on too lean
+1 on too rich
I agree that the Jardine headers are fairly thin walled.
Yes on idle is when it does it. I'll enrichen the Pilot screw by 1/2 turn and place a fan in front of motor tonight and see what happens. I didn't think the Main jets would have any effect on the idle mixture. Am I mistaken?
The mains do contribute a small amount at idle.
Give this a read.It explains how to tune CV carbs like our bike has. http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html
Excellent read! Thank you very much.
You're welcome.