Fuel pump/vapor lock?

[CP241]

Just drove it about 15 miles straight. 3x longer than I've ever driven it at once before and no issues! Not loading up on fuel when I go down a hill, and I didnt have to choke it at all on first cold start this morning either, another first

Does anyone know if this plastic seat is replaceable? If I can remove that little burr the carb is otherwise perfect. But you can blow it into the hole so it goes away, and I thought I had cleaned it out. But the fuel pushes it back in, it's like a piece of flashing from when/how that plastic piece was tooled.

[aghead]

I thought you were running out of gas. You had stated that the gas lines and filter were empty. Wouldn't the lines still have gas in them if the carb was flooding?

Edit..., I see your explanation:
...."I'm thinking thr needle was leaking, and not allowing the fuel lines to prime and pressurize (even though it's only 1-2 psi). Becauae of this, it was allowing air to seep back into the lines and cause the vapor lock."

[CP241]

Yeah, I think what was happening is because it never would be able to keep up, it never could build "pressure".because the needle.valve never closed, basically forcing it to lose prime and eventually stop pumping all together.

That's my theory anyway. Either way, swapping my.csrb with the spare seems to have resolved it. Now I just gotta.see if that seat is replaceable. If so I'll buy a new one and save this carb for my spare engine. If not ill have to be creative and figure out a.way to clean that out without damaging the seat, because its definitely.attached inside there somewhere or all the air I blew through it would have blown it out.

[KRAZYMATT]

Good, I know how frustrating it can be I was having same symptoms for
Months, even with multiple carbs. Hopefully that was it. Wonder where the plastic is breaking down and getting in there from..

[CP241]

It's the exact same color as the seat so I'm positive its flashing from the mold, and probably been there since this carb was new.

The motor was manufactured in 10/2013 and we know it's not at all uncommon for them to sit on a shelf for a year.or two before being sold and installed into a cart. I doubt it was actually used for more than a year or two, and I'm wondering if it wasnt a basket case and that's why they ended up dumping it because they couldn't figure out what was wrong with the new engine (and bought by a member here who swapped a vanguard in the cart).

[CP241]

Also I can confirm it was the carb :doh:

Runa great with the other one. This thing flies! And FYI the plaatic seat is not really replaceable. Stupid design if you ask me. My other carb has cast holders for the float bowl and a brass seat. This one was all plastic. I got it out (though not in one piece) and sure enough it was a straggler piece of plastic dangling around in there. No way I was gonna get this carb "right" without raning it out for sure had to cut it off.

The fuel.pump problems I was having are 100% caused by the float valve not sealing.

[Fairtax4me]

Looks to me more like the inlet was being blocked off by the piece of junk and would build pressure in the lines and force the pump to stop. Remember these pumps only produce about 1.5psi, so any Pressure in the lines will prevent it from pumping.

The needle seat is a press-in design that is not removable. It's basically glued in at the time of manufacture. I have had zero trouble with the plastic needles or seats on the old keihin carbs I have.

Can you post some pictures of the body of that carb? I have to wonder if that's a knock-off. The white plastic is too clean for that to be a very old carb. That stuff turns yellow/brown after a few years sitting in gas all the time.

[CP241]

Originally Posted by Fairtax4me

Looks to me more like the inlet was being blocked off by the piece of junk and would build pressure in the lines and force the pump to stop. Remember these pumps only produce about 1.5psi, so any Pressure in the lines will prevent it from pumping.

The needle seat is a press-in design that is not removable. It's basically glued in at the time of manufacture. I have had zero trouble with the plastic needles or seats on the old keihin carbs I have.

Can you post some pictures of the body of that carb? I have to wonder if that's a knock-off. The white plastic is too clean for that to be a very old carb. That stuff turns yellow/brown after a few years sitting in gas all the time.

It wasn't seating. I could hold the float up compressing the needle spring and still blow air through the fuel lnlet. Though it's still possible it was restricting flow as well.

As for everything being white and shiny and new looking, the carb is the one that came with the motor. Manufacture date on the motor is 10/2013, and it's not uncommon for those motors to sit on the shelf for a year or two after Kawasaki builds them before someone purchases it and installs it into a cart. The cart it was removed from was a 2008 so it was purchased as a replacement motor for that cart at some point. I doubt this engine has more than a couple years use on it. Heck, my carryall is a 2002 and out of curiosity I looked at the stamp on the motor and mfg date is 1998 I don't know 100% for sure that's the original motor that CAME in the cart, but judging by the condition of the cart when I bought it I can only assume that is the case.

I did get the seat out of the carb, but broke one of the tabs off that hold on the float bowl. It's held in with an O-ring but very, very tight. Had I known now what I knew then I would have gone about it a bit differently... but it "CAN" come out. It's just not very happy about it

I'll get a couple pictures of the carb body. It does say Keihin on the side and has the Keihin star, looks OEM Keihin to me. And if it's not, they did a GREAT job of faking it, better than any other fake carb I've ever seen before!

[CP241]

Heres a couple pics of the carb body. :)

[buggyAl]

CP - did you ever find a source for the plastic float yoke/seat? I have a carb in the exact situation as your photos. It got knocked off the bench and broke. Not a bad thing though I discovered that the "O" ring was defective.