Fuel petcock issue 1976 Kawasaki KZ-400-D3

Okay, so something like 99.9 percent of the parts on my '76 KZ-400 are almost 40 years old. Guess which one doesn't work? That's right, the NEW one.

Original petcock was leaky and corroded and you can't get rubber parts for it anymore. Honda sells one that is identical, but the outlets point down rather than horizontal. No biggie. I bought one, put it in, and it kinda worked. Annoyingly, it never did shut off completely.

Today I got around to troubleshooting why my right cylinder would start fine, then quit. Cause: Insufficient fuel feed. Pulled the lines and found no obstructions. The problem is, one of the two feed nipples only drips, while the other one puts forth a nice stream. WTF? I pull the cock apart, and find that while the casting would accommodate a dedicated feed from the bowl, they relied on a single hole, which feeds first one nipple, then the next. Problem is, the second nipple hardly gets any fuel.

Suggestions? I could drill out another passage or Y the lines together. Not sure the Y solution will solve the problem, since that's kind of what the manufacturer did. If I drill another passage, I'm not sure there's enough cast metal to tap and plug.

I'd fill the drip only outlet with something like JB Weld and use a T-joint between the carbs. KZ-400 can't drink that fast, can it?

I dunno. I found the original unit and test fit all the rubber parts. I think I can use the new part to rebuild the old part, which naturally has two discrete feed holes from the bowl, just like the new part SHOULD have. I'm soaking the thing in carb cleaner tonight. I'll put it together and test it out tomorrow.

Update: Well, it's back together, and it runs, and it does not leak. That's the good news. Bad news is, it still loses power above about 40 mph, which is where I was last fall. Ready to tear my hair out, well, what's left of it.

Are you sure it's the petcock? Even one working petcock should provide enough fuel to make it run at any RPM.

As much fun as it is, I would take a look at the carbs. Do you have one of these? Most of my carb issues were resolved with a little TLC, patience and one of these.

Dan

Okay question for you. Did you or someone "rebuild the carbs" were the float needles and seats replaced? If so were the proper units used? There's a number on the seat this number is a flow rate. gravity feed need the higher flow 2.0 or bigger. the 1.0-1.5 are for fuel pump equipped bikes if you use them in gravity at speed the bowls drain fast then they can fill.

44Dwarf wrote: Okay question for you. Did you or someone "rebuild the carbs" were the float needles and seats replaced? If so were the proper units used? There's a number on the seat this number is a flow rate. gravity feed need the higher flow 2.0 or bigger. the 1.0-1.5 are for fuel pump equipped bikes if you use them in gravity at speed the bowls drain fast then they can fill.

Yes! Absolutely rebuilt. Problem is, parts are a bit hard to find for these bikes today. The bike when purchased had no carbs. Two sets from ebay yielded enough good (now 40-year old) parts to assemble one good (decent?) set of carbs. The seats I believe are original to the carbs and in good shape. The float needles are in good shape, presumed correct, and the carbs do not leak. The original petcock is working great with the fresh parts.

I had the bike out today and rode to a bike shop to get state inspection, maybe 10 miles each way. Bike ran as well as it has in years. Still occasionally loses power right around 45 mph, but will get through it with more throttle.

Thinking I'm getting tired of an antique motorcycle. Looking at early 2000's Kawasaki Concours. Anybody got any experience with them? Seems like a budget alternative to a BMW, and I'm not interested in a cruiser or a crotch rocket.

You sir are on the right track. Concourse is a solid bike.

In reply to clutchsmoke:

Negative on the V-twin! Four in a row is the way to go!

http://en.wikipedia.org/wiki/Kawasaki_Concours

Great to here its running well again. Sudco and carb warehouse will have any parts you need. both are very good on knowing what came inside each model carb. Say away from e-bay kits and keyster junk that never 100% right stuff go OEM from Sudco.

Seems like the Connie 1000's vibrate a lot based on web comments; http://www.advrider.com/forums/showthread.php?t=298742

This seems like a common inline-four affliction. Otherwise they seem like excellent bikes but I don't know that I'd want to put up with the vibes.

pres589 wrote: Seems like the Connie 1000's vibrate a lot based on web comments; http://www.advrider.com/forums/showthread.php?t=298742 This seems like a common inline-four affliction. Otherwise they seem like excellent bikes but I don't know that I'd want to put up with the vibes.

Yeah, I had seen a bit on that previously. Hard to imagine it would be any worse than with a v-twin, given that inline fours are inherently better-balanced than a V-2.