Kawasaki FD620D running poorly. Help?!

[Rock Doctor]

Didn't you say you only backed your mixture screw out 1 turn?

RD

[gimmegreens336]

Thanks Spook - will do the spark plug test tonight.

RD - Yes, at first. When I put everything back together and put her in the field it seemed to run better the full opposite. I ended up settling on about 2 full turns from seated. Let me clarify, does the idle-mix screw regulate air or fuel? I assume fuel, so the more I loosen, the more fuel it allows. Is this right? So I have her opened up 2 full turns, the manual recommends 1 3/4 then tuning from there. If it is in fact flooding, I need to tighten the screw?

Thanks for keeping up.

[plott hound]

yes,you need to tighten the screw to lean out the mixture.if you follow the tuning instructions in the manual to a tee,its very easy.turn the screw in till it starts to starve,then back out till it starts to flood.the middle setting of these 2 extremes is what you want.mine was damn near 1-3/4 turns out.

[Rock Doctor]

There are no exact settings for a carb.On the body of the carb there will be a screw(usually brass).Screw it in clockwise til it lightly seats.Don't screw it in too tight as it will damage the tip.Then screw it out 1 1/2 turns.Start the machine.For the following adjustments go 1/4 turn at a time giving the machine about 15 seconds between each adjustment to react to the new setting.Start screwing the screw out(richer) 1/4 turn at a time til the engine starts to stumble from being too rich.Then counting the number of turns you make screw the screw back in 1/4 turn at a time(leaner) til the engine speeds up and dies from being too lean. Stop there.Now screw the screw back out half the number of turns you screwed it in.For example if you screwed it in 3 turns you would screw it back out 1 1/2 turns.It should be very close to being right.Adjust the idle and ride it.If need be fine tune the adjustment richer or leaner 1/4 turn at a time riding the machine between each adjustment.

RD

[Rock Doctor]

yes,you need to tighten the screw to lean out the mixture.if you follow the tuning instructions in the manual to a tee,its very easy.turn the screw in till it starts to starve,then back out till it starts to flood.the middle setting of these 2 extremes is what you want.mine was damn near 1-3/4 turns out.

Damn you PH, you could have saved me a lot of typing if you posted that 5 min earlier

RD

[gimmegreens336]

Alright, I'll mess with her in a few hours when I get home. I hope it's flooding so it's an easy fix. If I were to lean the mixture and she continues to bog down under load I guess I'll take the carb back off and do another one-over.

[plott hound]

Damn you PH, you could have saved me a lot of typing if you posted that 5 min earlier

RD

yikes!your post is way more detailed.

[gimmegreens336]

I got a new phone and waiting for the pictures I took to upload, it's giving me hell.

Here is my report:

Both plugs were loose, one I took out bare handed. The plug closest to the winch was wet with oil. The other plug seemed fine, if anything, gapped too small. (I'm buying the tool to measure gaps today) The valve cover on the firewall side has oil on it. Boo

As far as running goes:

I reset the idle-mix screw to manual specs, 1 3/4 counter-clockwise from seated. She idles like a champ. Good RPM, smooth shifts, choke not necessary to idle. I can give her wide open throttle when in neutral and she hesitates for a very brief moment to catch up, then she revs up good, I can hear it hit the governor and dial back just a notch. She runs awesome at wide open throttle in neutral. Sounds better than she's ever sounded. All signs point to GO....

until I shift into low gear and try to do some maneuvers.

At a low idle in low gear she seems to want to stay running, but as soon as I rev her up a bit she dies. Ran fine in neutral while tuning, even at high RPM, but not under load.

I anticipate some trash getting back in the carb, maybe plugging the main jet? Otherwise I could have botched the float when I reassembled. I set the float according to the manual but it required a sizeable adjustment to the tab holding the float plug/pin to make it sit parallel to the carb face like the manual recommended.



It sounds fantastic when running. It's never sounded so clean or idled so smooth. It's a shame it won't run! lol

[Rock Doctor]

Wait a minute, something is tickling my memory here. Not sure if I want to read all your old posts, might be faster to just ask.
Have you checked your valves and Pushrods?
These 20hp Kawi Engines will Start beautifully, Idle like a dream, and run like a POS under load if you have skipped a Pushrod out from under a Rocker Arm, or bent a Pushrod.

RD

[gimmegreens336]

I have not messed with the valves. I've never done any of this, the carb and throttle control assembly was my first time too. If people feel like it could be a rod I will start the research.

[gimmegreens336]

The valve cover firewall side with oil? on it:



The first two pics are the plug with oil on it, it's the plug on the front by the winch. The second two pics are the plug on the back.

[gimmegreens336]

Wait a minute, something is tickling my memory here. Not sure if I want to read all your old posts, might be faster to just ask.
Have you checked your valves and Pushrods?
These 20hp Kawi Engines will Start beautifully, Idle like a dream, and run like a POS under load if you have skipped a Pushrod out from under a Rocker Arm, or bent a Pushrod.

RD

Edit: It doesn't run at all under load. If it's still able to limp around with a skipped pushrod it doesn't seem that's my problem. It runs with low RPM, I'd say anything over about 30% throttle and it bogs down and dies. (Except when in neutral, it revs to WOT just fine in neutral... dies under load)

[Rock Doctor]

Edit: It doesn't run at all under load. If it's still able to limp around with a skipped pushrod it doesn't seem that's my problem. It runs with low RPM, I'd say anything over about 30% throttle and it bogs down and dies. (Except when in neutral, it revs to WOT just fine in neutral... dies under load)

This is worth checking, if for no other reason than to rule it out.
Very easy to check for damaged/Skipped Pushrods and set valves at the same time.

Pull your Sp Plugs
Pull your Valve Covers off (10mm)
Look at your Rocker Arms, There is one for each Valve, with a common shaft running through both (On each cylinder). One side of the rocker arms push down to open your Inlet/Exhaust Valves, the other side of each rocker arm is pushed up by a Pushrod witch gets its movement from your Camshaft.
If a Pushrod is out from under a rocker Arm, you will see it. If the pushrod is bent, you might not see it but if you reach down and turn your Primary Clutch to make the engine turn over, you will see the Rocker Arms slowly go through the motions of opening/closing your valves.

If all is well (I suspect it's NOT), you might as well check your Valve Lash while your here.
Get yourself a 10 Thou Feeler Guage (.010"), and a 9mm wrench
Run your piston up to Top Dead Center on the Compression Stroke (Both Valves will be closed) (You will be able to wiggle the rocker Arms by hand)
Try to slip the Feeler Guage between the Rocker Arm, and the end of the Valve Stem. If it slides in very easy, loosen the 9mm nut on the rocker arm and slowly turn the end of the adjustment shaft down snug (NOT tight, you need to be able to pull the feeler back out and push it back in) to the feeler guage, tighten the 9mm nut. If you can not get the feeler guage in there, loosen the 9mm nut, back off the adjustment shaft a bit, get the feeler in there, then snug down the shaft on the feeler, tighten 9mm nut.

This might help a bit

RD

[gimmegreens336]

Nice! Thanks for the break-down.. I am supposed to be going to a fall party this evening but I'd rather go out to the Argo... I'm anxious to check this stuff out. Hopefully I'll get out there this evening and I will report back.

Thanks a ton RD

[gimmegreens336]

I've familiarized myself with the parts diagram of the valve/camshaft assembly. I see what the rocker shaft and arms are, I see 2 valves per cylinder, I see how the cam gear operates the rods to "stroke" the rocker arms back and forth. I love learning about this stuff.

Question: On your video, you must be "running your piston up to top dead center" with the screw driver before you wiggle the rocker arms and measuring the gap? I don't quite understand what I need to do to run the piston to top dead center. Just need a little clarification before I ditch this fall party.



Edit: Can I spray anything on the valves/arms/etc to lubricate? What can't I spray? Lewis said these valves are notorious for getting sticky. There is seafoam in my gas now and I poured a little a few times through the carb.