I agree, something is causing it to get HOT in there. Look at this spark plug I just pulled out...
The ground strap is burned pretty far back, indicating a too hot condition.
I am using 93 ethanol free fuel since thats the only ethanol free in my area, but that shouldn't cause an issue right? (keep in mind im in the USA so we use RON fuel ratings! It depends on the state but most states use: 87/regular 89/midgrade 93/premium)
What I don't understand is how this could be happening. Y'all know from my other thread what all ive done to this bike-
The carb has been completely dissembled, sonic cleaned, and rebuilt reusing the factory jets that came out of it but all new rubbers. I even dropped the jets in the sonic cleaner to be extra sure.
The petcock has an inline filter on it going to the carb
The tank has been cleaned (tho its got a little rust build up again)
It doesnt seem to be a fuel issue.
It doesnt sound like its a oil issue.
what else could it be???
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To recap, and im sorry for the novel, ill put a TLDR at the bottom here but, the muffler has always been that blue, that was the previous owners doing and I found a spark plug 2 stages hotter had been installed. I also found the mixture screw on the carb was 7 turns out and had no spring or o-ring on it.
After the carb was cleaned and rebuilt the header started to change color as I was dialing in the pilot screw. I figured it was just that the pilot screw wasn't set correctly yet and I had things too lean. But no matter if I was 1 turn out or 4 turns out I didn't hear any rpm change or popping of the exhaust or any indication of what was correct.
I ended up setting the pilot screw about 2 turns out and running it. The header started to blue more at this point. I tried 3.5 turns out. Still it continued to change color. I figured it was from me riding at higher rpms for extended periods of time and the way the pipe was made, but if its a pipe in a pipe then it shouldn't do this!
I keep pulling the plug and thinking it was too lean. We shimmed the needle past its factory setting to get it one notch higher/richer, but I rode home and pulled the plug and thought it was still lean (looking back now I think it was probably fine, but that bluing exhaust and white plug insulator had me thinking too lean).
So I go for broke and put that 118 main jet I had laying around in it. Then it was so rich the spark plug was black and fowled out within 30 min of riding. Rather than throwing the stock 110 main back in I decided to pull that baffle out of the header pipe thinking maybe it was causing a problem.
Now it doesnt fowl out the spark plug. Pulled the plug after about 100 miles of riding and the ground strap was clean hallway back, indicating proper temp rang, the insulator was still white, but the ring around the base of the threads was a little black. After reading some online forums on spark plug reading, I concluded that even though the insulator was still white the base was indicating a slightly rich condition. Not enough to really be a problem, but I figured rather rich than lean.
So I planned to get a K&N filter and a new exhaust and get some of the 120 and 17.5 jets to accompany that per the "successful carb tuning" thread ive read on here. Figured the 118 main would be good enough for now with just the baffle removed and the plug seems to agree with that.
So I really don't understand what could be causing this hot condition of the engine and bluing of the exhaust pipes. The only other thing I can think would be either I have a cooling issue- like oil circulation, but I would hear things clacking if that were the case, or perhaps its just from running it at such high rpms for so long. Now im not great at hearing the rpms, im used to having a tach but I know im not winding it all the way out. the top speed on this thing is 75 ive found and im usually running 60-65 at most.
TLDR: mufflers always been like that, baffle in header removed, main jet increased to 118, needles been shimmed richer one notch beyond factory adjustability, spark plug looks good-perhaps a hair rich actually, the exhaust doesn't appear to continue to blue, but the blue might be spreading, hard to tell, when its warm and been ridden it looks very blue and like its spreading, when its cool it looks fine. No idea why its running hot. TEMPS are 250-280F at cylinder head middle, 310-330F at the exhaust flange, 150F and below as we move to the middle of the header and beyond to the muffler- which doesn't seem that hot on the exhaust and weird since its blueing more towards the muffler where its colder, especially now that that restrictor pipe is removed. its all very odd.
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Now, the last two days ive had a new problem develop that im about to start a new thread talking about, but basically, on my commute home- 32 mile trip with 55-65mph speeds most of the way- I got about two blocks from my house and the thing started misfiring like crazy. Like I thought I was running out of gas and flipped to reserve but that didn't help. Luckily I was right by the house. It died when I slowed down to enter the driveway but fired right back up like everything was fine.
I got home and checked and I still had half a tank of fuel.
I pulled the plug thinking it was running too rich... but it looked fine, a little rich like I was saying, but not fowled out.
The next morning, I ran the bike and it acted completely fine. I thought well maybe it was some bad gas (unheard of around here, but I tested multiple components and everything was checking out fine). The next day (today) I rode it 32 miles to work to meet the guys to go to the local car show, no problems, ride to the car show, then to lunch, then a few miles to my grandparents house to visit, then head home, all in all about 2.5 hours of ride time. And once again, I get about two blocks form the house, almost the same exact spot and it starts doing it again! Misfires, stutters, dies coming in the driveway, fires back up like nothing ever happened. I check again, got fuel, pull the spark plug and it looks fine although now it looks hotter than before, but we sat in traffic a while getting into the car show (to the point we turned the bikes off). But I can't figure it out. I jiggled the ignition switch around and the kill switch too thinking maybe its a bad connection there, I pulled the kill switch apart, solders look good, its all clean, passed the multimeter test too. Though maybe its a kick stand switch, I check and it doesnt even have a kick stand switch.
One thing I did notice lately is the Neutral light wouldn't come on leaving my grandparents house today and it refused to start unless the clutch lever was pulled (obviously). But that shouldn't kill it suddenly when going down the road at 60mph.
So im thinking maybe my ignition coil is failing or the glass fuses are vibrating loose or a bad ground perhaps, or the metal spark plug cap is arcing to the head to ground since its a little rich. I really don't know what's going on with this thing....
Idk why it would be running so hot and now randomly misfires and dying.
Topic: Exhaust turning blue? (Read 4374 times)