Kawasaki FD620D running poorly. Help?!

[Mike]

I'm sorry. I just finished moving photos in the engine section of the gallery to their own album here: Carb Rebuild - Amphibious ATV Pictures but unfortunately, it destroyed the links to the photo in this thread which means you will have to relink them. If I knew which photos went where I would do that for you but I don't. Sorry for the inconvenience. It was completely my fault and I know how time-consuming this can be.

If you have more photos to share, and I hope you do even though I ruined your hard work to this point, if you will put them in the album I created in your gallery, they will be safe there. Usually if there are a lot of detailed photos I will create an album to store them in so that the main gallery isn't full of dozens of detailed shots so that's what I was doing with your photos. If I realized how many were linked here before I did that, I would have waited.

Sorry again.

[gimmegreens336]

It's all good Mike! I've got a whole new host of problems now so hopefully I'll fill the thread right back up with pics.


Fred: The "strip"! lol - No, I've not been to one. Other than the one at Busco! Good advice on testing for carb leaks. I planned on running her last night and testing until we found some throttle issues. (Explained below) I already anticipate an issue with the gasket in the middle of the carb. I bought a new one, but it's so detailed and the ledges are so thin, it seems tough to get it to seal perfectly. I ended up snipping the end of the solenoid. Neighbor said it's not repairable. He said he'd snip the end or find a bolt that fits, and a cool-down idle for about a minute before shutting down should prevent back-fire. (We'll see!) Worst case, if it diesels or back fires like crazy I will just buy a new solenoid. Man I do appreciate your help! Thanks for keeping up man!


The last run at Busco before the Conquest took her final sh**, the throttle was sticking at wide open. It happened when we put a new driver behind the sticks and it was a mess. We took the handle off at Busco to look at it, didn't notice anything out of the normal. After reassembly, it has perm cruise control. The throttle does not return to idle when you release the handle, it sticks. (But it's the handle sticking, or the throttle cable - the arms and springs by the carb are operating as normal, something is sticking somewhere else) You have to forcefully twist back to idle. I was thinking if I took the handle back off, got WD40 down into the cable, and sprayed the arms and springs in front of the carb that everything would be ok. It's not! lol

I am slacking because I should have videoed what I'm about to try and explain. First, I haven't been on a research binge yet. I will edit this post if I find my answer no the site.

So does the handle throttle control more than just the throttle valve in the carb? I ask this because there is maybe 1" of movement in the throttle shaft, moving the throttle valve from closed to open. With just a very small twist of the wrist, I can open and close the throttle valve completely. So essentially, the last 80% of my throttle twist does not move the throttle valve. If there is another function the throttle serves fine, otherwise something is funny.

The carb is put together and installed, including the throttle and choke shafts. Everything seems correct. I don't love how "sticky" the throttle valve seems. I would love friction-less movement. The throttle valve doesn't seat at a perfect perpendicular angle to the carb bottom. When it "closes" it is slightly tilted. I guess this is normal? Just want to confirm.

Here I go on another research binge. Fred, the Argo is giving me an opportunity to learn some things for sure!

[Rock Doctor]

I ended up snipping the end of the solenoid. Neighbor said it's not repairable. He said he'd snip the end or find a bolt that fits, and a cool-down idle for about a minute before shutting down should prevent back-fire. (We'll see!) Worst case, if it diesels or back fires like crazy I will just buy a new solenoid.

I won't say that snipping the end of the Anti-Backfire Solinoid is the right thing to do, but I will say that if you check any of the 5 Conquest engines I have, you will find that all of them have the Solinoid Pin Clipped off.

The last run at Busco before the Conquest took her final sh**, the throttle was sticking at wide open. It happened when we put a new driver behind the sticks and it was a mess. We took the handle off at Busco to look at it, didn't notice anything out of the normal. After reassembly, it has perm cruise control. The throttle does not return to idle when you release the handle, it sticks. (But it's the handle sticking, or the throttle cable - the arms and springs by the carb are operating as normal, something is sticking somewhere else) You have to forcefully twist back to idle. I was thinking if I took the handle back off, got WD40 down into the cable, and sprayed the arms and springs in front of the carb that everything would be ok. It's not! lol

Just a thought, If you tighten the little screws on the hand throttle assembly too tight, the throttle twist grip will not return freely.

So does the handle throttle control more than just the throttle valve in the carb? I ask this because there is maybe 1" of movement in the throttle shaft, moving the throttle valve from closed to open. With just a very small twist of the wrist, I can open and close the throttle valve completely. So essentially, the last 80% of my throttle twist does not move the throttle valve. If there is another function the throttle serves fine, otherwise something is funny.

The Throttle cable runs to a linkage on the Governer, when you pull the cable, the governor linkage moves. There is a spring that connects the governor linkage to the throttle linkage. If you are looking at it and testing while the engine is NOT running, it would appear as though there is not much happening at the throttle.

Hope I didn't mess up the explanation on the throttle linkage to much

RD

[gimmegreens336]

Hope I didn't mess up the explanation on the throttle linkage to much

RD

No, that's what I was hoping for. There isn't much going on around the carb when I twist the throttle and thank goodness that's normal. I am going to remove the control panel assembly, inspect the governor arm, and do a good cleaning of all those arms/springs/levers before patching her up. I get off work in about 7 hours, hopefully have her put together tonight and begin tuning.

It sounds like you're telling me that clipping the end off the solenoid is, in fact, the right thing to do.

Last, I will try to loosen the screws assembling the throttle handle. I probably did tighten them thoroughly thinking the handle would slide off if I didn't tighten them. I was going to run some sand paper through the grooves that allow the handle and cable to turn, see if I can't route it out a little more.

I'm excited to get working again tonight. I really wanna get her turned over to see if my original issue is fixed.

Thanks for chiming in RD!

[JohnF]

... clipping the end off the solenoid is, in fact, the right thing to do. ...

"... the right thing to do." - Now that really involves ones own personal weighing of risk -vs- reward.

The point of the thingy is to shut off the flow of fuel so it doesn't get sucked through an engine that has been shut off while there is still a good deal of inertia; only to be ignited by a still hot exhaust system. This will pop and make the unaware jump and the kids giggle.

But, there are other options. Makes the carb easier to take out if you need to rejet.

Oh, and let it idle down for a bit before you shut it off.

[gimmegreens336]

Nice, thanks JohnF for the link - was wondering about which bolt size I would need to cap it. For now, it's installed with a snipped solenoid. I gravity fed a little fuel Saturday night and fired her up. She sounds sweet, much much smoother than before. I'd attribute the success to the correct plugs more-so than the carb clean.

My biggest issue right now is the throttle cable. It's in a bind. It looks like there is a bend in the cable around the handle that's causing it to hang up. I understand I can get this cable anywhere but I was more concerned with the pieces on each end. One connects to the handle, like a small sphere that fits in the hole in the handle, the other is a flat metal with the S shaped or whatever that fits on the control panel by the carb. Maybe this is an easy fab? I'm not sure..

I also took the control panel? (the piece with springs and arms connecting the throttle cable and choke cable to the carb) apart and cleaned all the grime and lubed it real good. The springs seem loose. They may need replacement.

The "new" shiny carb.


I hardly had an opportunity to work on her yesterday, we threw (my wife's idea) a gender reveal party with friends and family. We are having a GIRL! I'm pumped and already wrapped around her finger.

[Rock Doctor]

Try not to mess with the springs too much yet. The one going from the governor linkage to the throttle linkage should be loose when the engines not running.
Which others are loose?

RD

[gimmegreens336]

Try not to mess with the springs too much yet. The one going from the governor linkage to the throttle linkage should be loose when the engines not running.
Which others are loose?

RD

Jeez - I did bend/rig all of them to be tight before I started the motor... maybe that's why the RPM's are high at idle when I gravity feed the fuel? I think I can un-bend them. Hopefully I'll get to work tonight on it, I will report back tomorrow.

Thanks RD

[Rock Doctor]

Jeez - I did bend/rig all of them to be tight before I started the motor... maybe that's why the RPM's are high at idle when I gravity feed the fuel? I think I can un-bend them. Hopefully I'll get to work tonight on it, I will report back tomorrow.

Thanks RD

Yes that will make your idle high. At an idle, your governor should not be trying to control your RPM.
When the engine is stopped, there is no tension on the Governor Linkage.
At an idle there is some tension on the governor linkage, but not enough to activate the throttle linkage
By tightening this spring, you have put a bit of tension on the throttle linkage when at an idle.
If you pull your air cleaner off, and start your engine, I bet you will see that your throttle linkage is pulled away from the little Idle Set Screw. You can probably push the throttle linkage back to where it contacts your idle set screw with your finger, and your engine will idle down. When you release it, the tension from the governor linkage will pull again and idle the engine up.

RD

[Rock Doctor]

Oh, and get a spare spring to go from the Gov to the Throttle linkage.
Now that you've bent this one, it's compromised. It might last, it might not, but I can tell you "From Personal Experience" that you DON'T want that spring to break when your sitting on a frozen lake about 16kms from the nearest road.

Another point,
That spring is a very specific length, if you try to bend it back to where it was, and something still doesn't seem right, there is a chance that you don't have the spring bent to the right length.

RD