- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
It sounds as if a throttle cable or choke cable is either sticking or badly routed . Most bikes rev high at cold start then the revs should decrease as the engine warms up. I would check the throttle and choke cables first make sure they lubricated and operate smoothly and especially with the throttle cable if you open it slowly does it return immediately you take your hand away. It should almost snap shut. I would also check out the pilot air screw in the carb these get clogged with debris from the petrol over time. Before you take the pilot air screw out turn it clockwise into the carb and note how many turns it takes until it stops (do not over tighten this screw) be very gentle when you do this. Check your user manual to see if the turns in you found match the turns out in the manual. Also make sure the tick over (idle) adjuster screw is set correctly your bike should idle at approx 1,200 to 1,300 RPM when hot. My Yamaha 125 is 1,300 RPM my Suzy 650 about the same.
I would start with the easy less expensive stuff first.
Check/Replace your spark plugs. Carbon fouled, sooty plugs don't like to idle.
Clean/Change your airfilter. Dirty air filters choke the motor. choked motors either stall or rev high.
Carburetor idle screw needs set.
that is adjusted after the bike is warmed up to operating temperature, then set idle.
If that doesn't have you cleared up then you'll need to have your carbs cleaned.
Sounds like the idle circuit in the carb is restricted. The engine is running on the choke only. When the engine reaches a certain temp the fuelthat does get is more readily burned allowing you to back off the choke. The choke probsbly can't be completely opened? right? Fuel quality is also something to consider Oil content in fuel affects combustion temps and volatility. _good luck_Ned_
Could be one of two things
1. The carbs are gummed up. Modern fuel will break down after only a few months. The idle jets are quite small and will easily become blocked. Strip and clean the carbs.
2. The throttle cable is sticky. Less likely, but possible. Make sure it opens and snaps shut easily.
What do you mean when you say you tried more air?
Sounds like the carbs were not properly cleaned or set up. Choke should cause the cold start rpms to be higher than what you are experiencing. Application of choke to a warmed up engine will usually cause the engine to stall.
Depending on the type of intake system, if it's a normally carburettored bike, there is an air mixture screw on your carby(s). Set this screw at one and one half turns out from being screwed to stop. Run bike till it is warm and set IDLE screw or throttle stop at optimum idle revs. Without using choke or throttle, turn the air mixture screw slowly in or out till revs build to highest level. Reset idle screw or throttle stop to set revs back down to optimum level as before. If this does not cure your problem, depending on if it's a 2 or four stroke, single or multi cylinder engine your problem may be one of many from fuel ratio, valve rocker clearance, ignition, plug range etc....specify make/model for proper info.
100% the issue is too much air. get your carb checked, reduce air intake.
open the air intake on the carb about 4 full turns then start the bike. if it does not want to start open the idle bring it up at least 5 turns. when it start at a very high rev, start closing the air intake slowly until you feel and hear you have hit the right spot. adjust your idle in the process.
My 'wing won't run unless it has been warmed up some. I would suggest that you r&r your carbs to make sure the jets in the bottom are working correctly. They tend to get plugged up, especially after sitting & the aluminum flaking off inside... Rick