TOPIC:

Hi, I just bought a 78 KZ 650. Overall in great shape. It doesn't have a owners manual. I noticed that the fuel valve does not have a shutoff position. It had RES, PRI, and MAIN. My garage has a strong smell of fuel and the bike would not start till I pulled and dried the plugs and cleared the cylinders. Then it started great and did after till it sat overnight again. Am I not setting the valve right or do I need a new one??

P.S. I don't find any fuel on the ground.

Thanks

Post edited by: Cow_Man, at: 2007/11/25 09:00

You probably need to rebuild the petcock or go to a different one. You could just install a shut off valve in the fuel supply line in the meantime. Also check to be sure your float valves are working properly.

Post edited by: KZErider, at: 2007/11/25 09:09

Yeah I thought it might be the petcock I have never had a bike without a shutoff before. I need to pull the tank and fix a dent this winter so a new petcock with a shutoff is in order I think. I just joined today and have been browsing the forums and found a thread on petcocks. I am amazed at the quality of technical advice here.

Thanks.

The 3 positions are REServe, PRIme, and MAIN. Keep the petcock normally on MAIN. When the engine starts a vacuum will pull open a rubber diaphragm in the petcock allowing fuel to flow. When you shut off the engine the diaphragm shuts off the gas, in theory.

Reserve is for when you run out of the MAIN tank, and PRIME will bypass the vacuum shutoff feature allowing gas to flow directly into the carbs. This is handy if you have let the bike sit for weeks, or have a totally dry tank and just filled up.

Check Z1Enterprises on the right hand side of the screen and read the page about rebuilding petcocks.

Double check the oil level too, fuel has a way of getting into the crankcase. Open the oil cap and see if the oil smells like gas. If it does then you need to change the oil.

What model 650 do you have? I have a link to a 78 B2 model for the owners manual....even if you have a C or D model it should still work for you.

Let me know.

Also check out the link in my signature for more 650 stuff.

Kent

I have a 78 650 b2.
Thanks for the info I will check it out. I am very impressed with the response and quality of technical expertise in this forum. Makes me a little misty thanks guys.

Here is the manual link.

tinyurl.com/2cp7k3

Got it OKC_Kent. Thanks a bunch. It has a lot more info than the new ones.

Welcome to KZr Cow_Man.

If you're planning on sticking with OEM parts and are going for a resto, be aware that the OEM petcock (51023-1023) for the '78~ KZ650 is no longer available.
In fact, the original part number has superceded 4 times (51023-1370, 51023-1011, 51023-1013, 51023-1005) over the years, and all of them now are no longer available.

When I replaced the petcock on my '78 KZ650-B2, I just checked what other current model Kaws used the same oval o-ring (51039-013) that mounts it to the tank, and then researched which petcock was still available.

The Kawi '05 KZ1000-P24 (last production year of the Police bike) just happens to use that same o-ring, and since it's newer than my '78, parts are still (for now) avaialble.
The petcock for the Police bike is a 51023-1375.
And aside from the obvious part number diff, the only things diff are the direction the fuel and vacuum fittings face coming off the back of it.
IIRC, when I bought that same petcock 3 years ago, it ran me around $85 +tax.

Of course you can always follow Kents suggestion in checking with Z1 Enterprises, which I believe is a less costly sollution. I've heard the Suzi petcock is comparable to the Kawi and a lot cheaper.

Post edited by: RetroRiceRocketRider, at: 2007/11/25 10:35

Love the pingel petcocks

Post edited by: kwakagoose, at: 2007/11/25 12:36

I just pulled the tank and drained it into a gas can. I put a hose on the vacuum and sucked on it to control the valve, it seemed to work properly. I think I will put on a valve with a shutoff anyway just because that is what I am used to. Thanks for all your helpful info.

And another thing! I you smelled gas strong,,, it could be that it drained into the float bowl and then into a cylinder and past the rings to dilute your oil. Check your oil for the smell of gas. If you smell gas, change your oil because it has been thinned by the gas. Dont want you spinning a bearing on a creampuff. Joe