Diagnosing carb problems on 1993 Yamaha XT225 Serow with a Mikuni CV

My bike broke down while on a riding weekend out in the mountains of PA. Turns out a vacuum line hose which had been plugged fell off allowing the bike to run lean.

[@kevinmithnick9993]

Sometimes I run it without the rubber that goes between the carb and the air filter. You can see the behavior of curtain when accelerating, if I notice no rising when opening throttle then I carefully lift the curtain to see what happens.

[@BarryGrumbine]

I think only 1993 XT225C sold in California used the vacuum port. My non-CA bike's port is capped.

[@briansilveira1195]

I got the same bike this helped alot thanks

[@jackstrawfromwitchita5978]

If you want to see if there is a vacuum leak , spay some ether or starting spray around the carb while the bike is running. If there is a leak your RPMs will raise momentarily.