air leaks.

So what ive done so far is: new carb holder/mounts, new air box rubbers, new z1 type hoods for the vacuum ports on carbs, cleaned carbs, new clamps for the carb holders, tightened everything up good. but still seems like there are a slight leak somewhere.. idle is all over the place, either 1500, 2500, 2000.. slow to come down to idle, and hangs.. and dies sometimes. might hang up at 2500 then come down to 1500, maybe 1000 and the die..different idle every time i come to a stoplight. could this just be carb sync or do i still have a leak somewhere? the hose going to the tap seems tight enough? could this be it?

everybod likes pictures, so i added a random one.

When was the last time the valves were adjusted? Do routine maintenance first before going to the carbs.
Steve

With engine running, could try spraying WD40 over possible air leaks sources and watching for exhaust smoke due to ingested WD40 (and perhaps also a change in rpm).

Varying idle rpm might also be due to a mechanical issue with the throttle cable, anywhere from the handlebar twist mechanism to the connection at the carb bell crank, or a slack adjustment might be needed, or maybe the interion cable is frayed, or throttle cable needs lubing, etc.





Good Fortune!

Carb slides could be sticking. Had it been sitting?
Steve

Are you sure it's an air leak? Have you set the idle mixtures? Did you use any sealant when installing the new carb holders? If so, did you let it cure for the amount of time specified in the instructions before starting the motor? Did you torque the bolts on them to spec?

As swest hinted at, too tight intake valves can cause lean-condition-like symptoms when the bike warms up.

thanks for the tips!

Havent done a valve adjustment, was thinking that i should sort the carbs first, since that was something i could do on my own right now and didnt have to use a shop. The bike have been sitting for aprox 7 years so i guess i have to try lubing the gas wire and checking if the slides are sticking. i did not use sealant on the carb holders just put them on dry as i was told to do.. the old ones did not have a gasket or sealant either. torqued the bolts to spec. pilot screws set at 2 turns out as specified in the FSM

better go get my WD40

If you happen to be one of those unlucky blokes who has a head with intake valves that are slightly leaking, because the valves not been adjusted properly, it will spit exhaust or mixture compression from cylinders right back in the carburetors and Jack up anything you're trying to do with the carburetors....

It is folly to go straight to the carbs when normal maintenance hasn't been done. It is common for new owners to avoid doing them due to the time, work and money involved. Once done, they can last as long as 3000 miles. You might be able to get it to run but it will never run right and possibly quit running until a major valve job is done. Cheap insurance.
Steve