In the kit I found a small red, round gasket. The instructions were lame and did not mention it or even where to use it, so I used that between the carb and intake tube. THAT was a mistake! When I took the carb off to address the idle issue, the little red gasket was missing. It had been sucked into the intake. Fortunately, it didn't make it into the engine. I took the intake tube off and got it out. I used that as a rough template to make the new gasket from the gasket material I had. It fits in the carb very snug, so I don't think it will get sucked in. But I know somewhere I have an assortment box of rubber O-rings so I'll swap one in.
Yes, by erratic I mean that the engine speed goes up and down on it's own. Not by huge a amount though. Couple hundred RPM up and down. What is normal idle speed? Right now I have it set pretty high IMO. But if I lower it too much more it will die. I've watched alot of youtube vids and at this point I can't get mine to idle that smoothly.
ok, first of all, gasoline will destroy a rubber o-ring. BUT, you can try a rubber o-ring temporarily just to see if it solves the problem.
you need to go to sick bike parts and order some of their o-rings specifically for this. They are made of fuel resistant Viton.
here's a link for the o-rings.
http://www.sickbikeparts.com/catalo...ducts_id=51&osCsid=01eg3n4lovo147vqjd0cvknf75
i suspect that you may have a float adjustment issue which could be causing the erratic idle. if the float level is set too low, your carb could be getting close to running out of gas, which will cause a lean condition, and make the rpms go up. Then the float bowl re-fills which will richen the mixture, causing the rpms to go back down. whenever an engine runs out of gas (float bowl empty, gas tank empty) the engine rpms will increase on their own right before the carb runs out of gas completely. this is making it run lean (too much air, not enough fuel).
either that or you have a tiny air leak either at the carb-intake tube connection, at the intake tube - engine gasket or at the carb cap. the carb cap shoudl be hand tight only, but they can still leak because the machining . casting isn't the best.
someone had this problem and they put a small gasket under the carb cap and it cured it. I'm not sure what they made the gasket out of tho. I think they just used a fiber washer....I can't remember.
go get yourself a can of starting fluid.
With the engine running LIGHTLY spray the starting fluid around the connection between the carb and intake tube, the intake tube and engine gasket and the carb cap. if the rpms go way up when you spray one of these areas, you've found your air leak. do one area at a time and let the engine run for a few seconds between sprays so you know which area the leak is coming from. if you spray the whole carb at once and you do have a leak, you'll never know where it's coming from.
second of all, your idle should be smooth and it should never vary in rpm...just like your car. your engine should sit there and idle smooth..mine will idle all day long and never change. what is the correct idle speed? well, that's all personal preferance, there is no "right" idle speed. as long as it's not racing really high, and able to stay running when you let off the throttle with the clutch in. that's all that really matters. you juyst want a nice, smooth "pop-pop-pop-pop" idle
for example, here's a video of one of my engines sitting at an idle. I do rev it on occasion but i was trying to show the sound of my custom exhaust.
http://www.youtube.com/watch?v=Ry-Sjb_HQao