Bike runs on PRIME but dies on RES or ON...

Hi Everyone,

So I recently sold my other 78KZ650 SR and switch the carbs from my daily rider KZ650B2 to the one I sold (SR). I figured it's easier for me to tune the carbs on bike I use everyday than the one that sat for a while...so I thought. The SR carbs used the gravity feed petcock and the B2 uses the automatic petcock so I know the vacuum port has to be open so I removed the plug that was on it. The problem is the bike runs for a while on "res" or "on" position but will die after a while (after the bowls have been consumed, then if I put it on Prime it will start right up again. I don't think it's the fuel valve because it worked before switching the carbs. What am I missing here? Any input or feedback would be highly appreciated.

Thanks in advance.

Have you tried putting the vacuum line back on? :woohoo:

never mind - misread reply