The Prime position and the vacum hose

Okay, another two part question for the seasoned and wise:

1980 KZ550c. On the petcock, there is a "Prime" position. When putting the lever on both reserve and normal "on," the petcock seems to work fine. When switching it over to the "Prime" position, gas starts pouring out of carbs #1 & #3 overflow tubes. Carbs #2 & #4 seem unaffected. Is this normal, or am I missing something here?

Second question: Does the vacum line have to be connected for the bike to run? And I mean in the short term. I do intend on re-installing the line, but I am just trying to get the bike running first to make sure it is going to go before I do a full button-up job.

KB02 wrote:

Okay, another two part question for the seasoned and wise:

1980 KZ550c. On the petcock, there is a "Prime" position. When putting the lever on both reserve and normal "on," the petcock seems to work fine. When switching it over to the "Prime" position, gas starts pouring out of carbs #1 & #3 overflow tubes. Carbs #2 & #4 seem unaffected. Is this normal, or am I missing something here?

No, the petcock is working correctly, but your floats or needle valve in #1 & #3 need to be set/cleaned/ or changed.

Second question: Does the vacum line have to be connected for the bike to run? And I mean in the short term. I do intend on re-installing the line, but I am just trying to get the bike running first to make sure it is going to go before I do a full button-up job.

No it doesn't, but you will have to use the PRIME position, and plug the vacuum hose end until you are done and ready to hook it all back up.

Post edited by: OKC_Kent, at: 2006/04/17 12:24

Thanks!

Darn it. I didn't want to have to take those carbs off again. Oh well.

Well, it's tough but you don't have to remove them. I was able to adjust my float levels with the carbs on the bike. Tight fit if you have big hamhock size hands, but it helped when I used allen head screws on the bowls. I used a bent paperclip to pop out the float pins, and I caught the needle in my hand as it fell out.
Maybe a bit of dirt is in the float needle seat, see if you can spray some carb cleaner and try to direct the spray from the red hose up into the needle jet. May as well since the float is out getting adjusted.