High idle or hanging idle when warmed up. and 2nd carb from left backfires or coughs.

Nevr evr change parts til u know issue. Probly just needs a throttlbody cleanin. TPS may hav problm..its on the body. Idleair control dirty or faild workn. Du a scan to rule out these items. A partstore can show how to clean.

check your float height? sounds like its high and runs normal when cold like the choke is on but when warm its getting too much fuel.

Sounds like a blown intake gasket. The expansion and contraction of metal from heat would cause the high idle cold and power loss when warm. Use Carb cleaner and spray along edges of intake to see if rpms change. Take your time. Sometimes, unplugging the idle air control will help you find the leak.

The carbs are probably out of sync. Set the carbs so that both slides crack open at exactly the same moment. Next, balance the carbs by disconnecting one spark plug then turning the throttle screw on the runing carb to a slower and slower rpm until the bike stops idling on one cylinder. Now reconnect that plug and disconnect the other. Do the same thing to the point the engine dies trying to run on one cylinder. Now start the bike up with both sparkplugs in place. The idle speed will be high, but now the carbs are in balance. Turn each throttle screw down in equal portions until proper idle speed is attained. It would be a good idea to set the valve lash also. If the backfire continues, chances are the valves need to be re-seated. Re-sync and balance the carbs after the valve re-seating. Please rate my answer. Thanks.

All most positive it is in your carb take the bowl off it as you take it off there is a small tube that hangs down that all most reaches the bottom of the bowl need to take a small wire and push through it it is blocked .symptoms backfiring no idle coughing and sputtering if it does start

This sounds like an air leak is making the fuel/air mixture too lean. Any air leaks between the carb and the head will lean the mixture. Old, hard and cracked rubber manifold parts are the usual culprits. Old gaskets and "O" ring seals can leak air also. A bad head gasket seal happens at times also, as does an exhaust valve not fully seating. Air leaks are the idle speed problem.

A different problem is likely present in the carbs and that is what is causing the rich fuel smell. The carbs must be balanced. Example > If three of four carbs are perfectly balanced and one carb is not, then the 3 are "driving" the 4th carb. This will cause gas to spit into the air cleaner from the "bad" carb and can cause a backfire or two. Special vacuum gauges are needed to balance the carbs. Also be aware the carbs must be scycronizsed as well. The slides on all four carbs must lift at exactly the same time when the throttle is cracked.

Go to the site below where you can see a parts diagram for your specific bike. You will select the actual brand, year, model, etc., once you go to the site. Part numbers and prices are also shown. You can order parts from this site. In the event no price is shown on a particular part, the part is not in stock. www.babbittsonline.com/pages/parts/viewbybrandand/parts.aspx

I don't get paid for my answers but I do take pride in them, and I am only trying to help. So if you will, > > A “very helpful” rating for these answers? Thanks!