Kawasaki FD620D running poorly. Help?!

[JohnF]

The picture there isn't very good. If you've never seen a float and needle before then that thing is't helping you.

Hold yours upside down like in the picture and take a pic and post it. What I want to see is if you have the tab between the valve and its little keeper wire. If you have it on top of the wire then you effectively have your fuel shut off.

[gimmegreens336]

Nope, you're not to this yet. Once it's running well.

10 4!

[JohnF]

Nope, you're not to this yet. Once it's running well.

Stick with your instinct that you aren't getting enough fuel in the bowl. Might be that all of your parts are okay but you have a really bad adjusted float.
Review 2-13.

[gimmegreens336]

Haha! I see that!

I have def not done this... not sure I understand either. Does this have anything to do with my issues?

[JohnF]

Yeah, all FD620Ds and FD661Ds have the same carburetor. Uh, model... That's actually in my other post, hold on... wait, I'll link the file here too <going advanced>:

FD620D-FD661D jetting.jpg

Go and download the service manual.
It's a terrible picture but page 2-8 describes how the carburetor works.

The main jet is at the bottom of the fuel bowl and is supposed to always be under the fuel level in the bowl. what I meant by un-porting here was when the jet moves above the fuel level and air start moving through it.

[EDIT] Oh, too late, I was typing...

[gimmegreens336]

I hope you're not typing while I'm typing this.

A perfect explanation of the flow is in the service manual. I read this explanation a million times when I first started this thread but my understanding is much better now. I understand everything that needs to be un-obstructed. (I think.. lol)

Let me clean this one more time and re-install her and see what happens.

Will check back.

[gimmegreens336]

If the float was stuck closed then it wouldn't run at all. Yours is running at low idle.
If the float didn't open enough to allow a fuel rate enough for high idle then it would probably reach high idle and then surge. Unless it was really bad, then it would die.
The float level affects the "accelerator pump" function of the carburetor. This functions is accomplished via an immersion tube (huh, the parts blowup in the manual above calls it an Emarsion Tube???) that sits in a reservoir. When call for, the fuel is sucked out of this reservoir. As the level drops it un-ports air holes in the tube effectively increasing air. What is trying to happen here is when you open the throttle the air flow can accelerate faster than the fuel which is heavier so the carb meters a bunch more fuel at this change over. The important part (sigh) is that the reservoir level is the same as the float level. If the level is too low, then the air/fuel gets too lean and the engine dies. If this is the case, you should be able to creep slowly to high idle.

As a side note, the main jet is in the bottom of the float bowl. If the float is set too low the engine will run fine on the level but die when the jet un-ports. Probably pointed downhill or port side high. That's really a function of the float bowl geometry in the design but a too low float adjustment screws that up.

I'm still thinking bypass holes are plugged. Second guess is fuel pump or float valve not allowing enough fuel flow through.

And for draining I usually unplug the fuel pump and let the engine run it mostly dry.

Here we go, save the back peddling.

Edit: Is the carb the same for all these Conquests with FD620D? If so, what is the model? I wanna see where all the fuel travels through it... Or you could just explain it all :-D

Re-Edit: What do you mean, when the main jet un-ports?

Thanks!

[gimmegreens336]

I see what you're saying.

I want to take some pictures when I get home of the carb before installing. I've dropped, emptied and cleaned the tank. Replaced the fuel line, fuel filter and fuel pump. Getting good fuel flow up to the carb. What would the symptoms be if the float were getting stuck at the top?

I need a better understanding of the flow of fuel through the carb. It enters from the fuel line and has to pass the float needle immediately? If the float were to stick at the top would it prevent all fuel from entering?

I am going to go back a few pages and read your explanation of the carb again. I read, re-read and re-re-read when you first posted but a lot of it was spanish to me. I am soaking this information in though please keep it coming!




EDIT: Disregard this post

[JohnF]

Did you snip all of the narrow portion of that anti-fire solenoid off? I had problems that sounded like yours that went away when the anti-fire solenoid went away. What is the condition of your fuel line? If it is coming apart inside it will plug up your main jet (just like an anti-fire solenoid ).

When it is dead is there fuel in the bowl? You can take the lid off and peek. If so, I suspect something is plugging the main jet. If not, then float, float valve, fuel line, pump, filter, tank...

GEEZ. I read your post but I didn't READ your post... You already suspect that there isn't fuel in the bowl.
A float that doesn't float will run the engine really rich and/or spill fuel out the vent hole in the top of the carburetor.
Check the float valve. There is a picture in the service manual. Usually they wear out and stop stopping fuel so act just like a float that doesn't float.
So, float that sticks up or valve that sticks closed or plugged fuel line.

I think you are on the right track.

Not seeing fuel dump when you twist the throttle could be a plugged immersion tube.
- or a too low float level.

I keep editing - I hope you are getting these.

[gimmegreens336]

Pump is pumping! Couldn't see any trash in the dimple in the bottom of the tank, blew out that little hose to be safe. Same problems. It's carburetor related. When you twist the throttle while it's idling you should visibly see fuel squirting down the throat of the carb, right? I don't see anything... Also, when it won't start at all, if I pour fuel down the throat of the carb she starts up for a sec, might smoke a little, then dies and coughs a little smoke out the carb. Carburetor is removed and disassembled again and I'm gonna blow her out for the final time. I still swear the bowl isn't filling up with fuel. When I loosen the drain screw there is less than 1oz of fuel that comes out. To me, that's an empty bowl. I want to order a new float assembly but then I wonder if I should just order a new carb?

That reminds me...

It looks like the carb, or my gasket, fits wrong? Check the pictures out. The gasket fits the carb but does not fit the top end correctly. It is the same shape as the old gasket that was installed, although the old gasket was not metal. Also, a small rip was in the gasket right below the tab on the gasket.





Hard to see, but the gasket doesn't fit the top end well. There are metal ledges that stick out around all sides. I was wondering about the seal.



The metal gasket left a little metal residue around the post. What causes this? Heat?





Anyway, I ordered two new gaskets last week, should be here soon.

Thanks for everyone's help!

[gimmegreens336]

Installed the new pump, was just as loud as the old pump so I guess these things just hum?

Result: worse operation. lol

Anyway - to follow-up on rapidroy - You're talking about the little coffee cup sized dimple in the bottom of the tank that the line rests in? That would be a good place for trash to rest. I did empty and clean the tank when I started working on this. I also replaced all the fuel line except for the piece down in the tank. I'm gonna take it off tonight and see if it's obstructed. I was pissed after she acted worse so I didn't check anything at all. I didn't even check for fuel flow at the carb. I plan to work a little tonight with it. Will followup with results.

Thanks yall

[rapidroy]

Bought a new fuel pump. Will install tonight. I'm running out of options. I think it's fuel related. Next will be a new carb?

Just a thought here to throw my two cents in with the rest. In the gas tank below the pick up tube is a small dimple, i believe it is a good place for water to collect along with other things that could clog the end of the tube and then fall out when you turn the key off. Wont cost anything to check for obstructions, though you might have to pull the tank to flush anything you find in there. If it is a bunch of water then iso propyl alcohol will remove it without pulling the tank. Good luck // RR

[JohnF]

... the primary clutch spins real fast while in gear even when belt is not spinning. Is this normal?

The primary clutch (or drive pulley) only spins when the engine is running. To stop it's spinning, turn the key off.

[plott hound]

Bought a new fuel pump. Will install tonight. I'm running out of options. I think it's fuel related. Next will be a new carb?

great prices on kawi engine parts at beiler engines.i bought a lot of goodies from them this year.

[gimmegreens336]

Bought a new fuel pump. Will install tonight. I'm running out of options. I think it's fuel related. Next will be a new carb?