new 80cc engine dies on idle

[Zach]

Hey all, I just signed up to this forum, but during my build I found this site INVALUABLE in helping me build my bike! My only problem as of day 3 is that my bike can't idle at all. I've messed with the idle screw many times. There was a black sooty liquid leaking from my exhaust and I couldn't put the choke on at all without the engine dying. So I guessed the mixture might be rich? Got on the forum and learned how to move the e clip up on the needle. (put it second from the top) The engine performed A LOT better and almost was going to idle, but no matter what I did the thing would just die! So is this just because of a new engine? Or is there something screwed up with my carb? Or am I, in my newbiness, missing something? Thanks! Btw, running a 16:1 oil ratio. Using walmart oil.

[borntofli]

Too much oil, go to 20-24:1.......They run crappy till you get a couple gallons thru it....

Check for intake leaks and put some miles on it.......

[crassius]

if it is a bgf kit, you'll want to go to the top of the needle with your clip - their mains are way too rich these days

[borntofli]

I have 3 bgf engines have all 3 w/ a 66 jet...Stock is 70....

I'm at sea level so inlanders would need to go to maybe a 63-4........


Lean them out and they run great.......

[Zach]

Alright I'll lean the oil out. Yeah, it is a bgf engine, thanks for the tip crassius. Hey borntofli could you point me to a thread that talks about changing jets? My elevation is 1400 ft. Also where do you buy them?

[borntofli]

You want the 5mm jets from sick bike parts..... They are hard to screw in cause they have different threads but they work and its your only option.......

[Zach]

Sweet. Thanks man. Did you ever have to mess with your floats or does the jet change and high needle clip setting about do it?

[Trevorsking]

What kind of carb do you have? If its an NT, I screw the idle screw all the way in and then back it out 3 1/2 turns , this has always worked for my NT carbs, you might have to make a very slight adjustment from that starting point but very little. Let us know if it works for you. If you don't have an NT, I have no clue, cuz I don't have anything but NT, someone else here can give you a good tip on those type carbs

Ron

[Trevorsking]

Zach,

Just to be clear, when I say turns I mean 1 full revolution (360 degrees).

[BikeBerryKelci]

Originally Posted by Zach

Hey all, I just signed up to this forum, but during my build I found this site INVALUABLE in helping me build my bike! My only problem as of day 3 is that my bike can't idle at all. I've messed with the idle screw many times. There was a black sooty liquid leaking from my exhaust and I couldn't put the choke on at all without the engine dying. So I guessed the mixture might be rich? Got on the forum and learned how to move the e clip up on the needle. (put it second from the top) The engine performed A LOT better and almost was going to idle, but no matter what I did the thing would just die! So is this just because of a new engine? Or is there something screwed up with my carb? Or am I, in my newbiness, missing something? Thanks! Btw, running a 16:1 oil ratio. Using walmart oil.

You have black soot just a couple things to try, check your oil to fuel ratio you might be running it a little too rich. Also you might want to clean out your exhaust pipe. For your carb tuning make sure your adjusting the jet needle inside the carb, for above sea level try working top to bottom and for sea level or below work from the bottom up. Each time you set it at a new notch turn you adjustment screw all the way in and let it out about a 1/2 turn to 1 complete turn. Make sure each turn you are trying to start the engine, but Not full throttle it will flood out your engine. Hope that maybe some of these tips will help!