78 KZ 650 B2 Vacuum Petcock Problems

I've been having trouble with fuel getting into the vacuum line on the petcock due to a torn/worn diaphragm. I ordered the K&L rebuild kit, but the diaphragm in the kit ended up being completely different and I wasn't able to use it. I managed to find a quick fix, but now there's fuel seeping into the vac line again.

I'm looking at a couple replacement petcocks on ebay, but I'm afraid I'll keep having the same problem with the diaphragms disintegrating. Does anyone have any suggestions on what kind I can look into?

Thanks!

Zach D.

Check out these threads over on kz650.info

forums.kz650.info/index.php?topic=1221.0

forums.kz650.info/index.php?topic=8222.0

I'm running the Suzuki one, it works great but the fuel outlet comes out the wrong side so you need to run a longer fuel line.

Go manual.

I replaced the one on my 82 CSR with a manual one and never looked back.

I suggest you just rebuild it using the correct parts from Kawasaki rather than relying on an aftermarket kit. The diaphragm, gaskets, o-rings, and spring are all still "Active" parts so any online or local dealer can order them for you. The total cost at Partzilla.com is $20.41 for all 7 parts. Ed

Thanks for the help everyone.

I decided to order the parts online and go from there - I had to remind myself that I want to keep everything as stock as possible ha. Thank you Ed.

Having went the Z1/suzuki petcock route, AND cleaned my tank vent (Thanx again, 650Ed!!!) I thought I would weigh in on this one....Unless I run on "prime", I am still experiencing fuel starvation issues at 50 mph plus. May try to rebuld original. Might go for one of those snazzy non-vacuum "made in the midwest" versions...I DO like the sound of that....might just keep remembering to switch it when I get on/off...GOTTA get SOME reliable source of fuel to her..they bog at the wrong time, and it can make for a bad day! I suspect that it is probably not the petcock's fault...I am leaning toward a low vacuum signal due to low(ish) compression, not fully opening the diaphragm.Thoughts, experts?

Do you have a fuel filter that could be clogged up? It took me a month to figure out my bike wasn't getting enough fuel because the filter was bad :whistle:

Thanx, but brand new, (polaris type) in-line.