Molotov256
Member
Hey all, and thanks again for your help with my last post, "Hi Rev Bog Down". This is kind of a follow up post to that thread which is located here:
http://www.motoredbikes.com/showthread.php?t=20936
I'd been having trouble with the engine bogging at high RPM, and Enflamed pointed out the notches on the carb needle and how moving the e clip could change the mixture. He suggested leaning out the mixture by moving it to a higher setting. I did that, and at first, it made a world of difference, but after taking it for a good 15 mile ride, it started bogging again.
Eventually, it started revving really high when I pulled in the clutch. When I pedaled to get moving again and engaged the clutch, it strained and sputtered at really low rpm and barely propelled me along. I tried to do a field adjustment on the clutch, but no problem there. I killed the engine and pedaled the rest of the way home.
Anyhow, I messed with the e clip a bit, and got the bike running again at a richer setting, but I'm back at square one with the bogging at high RPM. I've read in other posts that the position of the needle will only effect the mixture at 0%-70% throttle, but the really high end throttle depends on the main jet. According to a knowledgeable coworker, he says it sounds like the bike is running lean at high revs.
That being said, if it is running lean at high RPM, I'd need to widen the main jet, right? I read a great post about making the jet SMALLER here, but nobody seems to be interested in making it bigger. Am I on the right track, or am I being insanely stupid about this? I'm a bit gunshy about drilling the main jet until I know what I'm up against.
Here's a pic of my spark plug - it's light grey and dull, which leads me to believe it's running lean as well.
<a href="http://s6.photobucket.com/albums/y208/Molotov256/?action=view¤t=Plug.jpg" target="_blank"><img src="http://i6.photobucket.com/albums/y208/Molotov256/th_Plug.jpg" border="0" alt="Lean Plug Jun 09" ></a>
Thanks in advance for any advice!
http://www.motoredbikes.com/showthread.php?t=20936
I'd been having trouble with the engine bogging at high RPM, and Enflamed pointed out the notches on the carb needle and how moving the e clip could change the mixture. He suggested leaning out the mixture by moving it to a higher setting. I did that, and at first, it made a world of difference, but after taking it for a good 15 mile ride, it started bogging again.
Eventually, it started revving really high when I pulled in the clutch. When I pedaled to get moving again and engaged the clutch, it strained and sputtered at really low rpm and barely propelled me along. I tried to do a field adjustment on the clutch, but no problem there. I killed the engine and pedaled the rest of the way home.
Anyhow, I messed with the e clip a bit, and got the bike running again at a richer setting, but I'm back at square one with the bogging at high RPM. I've read in other posts that the position of the needle will only effect the mixture at 0%-70% throttle, but the really high end throttle depends on the main jet. According to a knowledgeable coworker, he says it sounds like the bike is running lean at high revs.
That being said, if it is running lean at high RPM, I'd need to widen the main jet, right? I read a great post about making the jet SMALLER here, but nobody seems to be interested in making it bigger. Am I on the right track, or am I being insanely stupid about this? I'm a bit gunshy about drilling the main jet until I know what I'm up against.
Here's a pic of my spark plug - it's light grey and dull, which leads me to believe it's running lean as well.
<a href="http://s6.photobucket.com/albums/y208/Molotov256/?action=view¤t=Plug.jpg" target="_blank"><img src="http://i6.photobucket.com/albums/y208/Molotov256/th_Plug.jpg" border="0" alt="Lean Plug Jun 09" ></a>
Thanks in advance for any advice!