My turn with carb troubles....

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coffee_brake
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#11 Unread post by coffee_brake »

Gummi you were just about on it.

I never heard of synching the choke so this last run, I looked at the butterflies to see if they were nearly the same. Good side was fluttering away, bad side wasn't moving at all.

Comparing the carbs to the parts carbs carcass, looks like the linkage for the two choke butterflies was bent and locking down the bad side.
Once bent back to allow both butterflies to move together, I have the left side running. It wasn't getting air to burn the fuel on choke.

I'm still left with the problem of idling very high off of choke. No matter where I adjust the idle screw it just revs very high. When I try to give it throttle, it dies.

I still feel a whole lot better, though. Now I'm back to jetting, right?

Thanks everybody, if anyone has been through this kind of jetting scenario I sure would appreciate any advice or help. I've only maintained my own machines; I haven't ever done jet work. Clear info is hard to find.
Jenn S.
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1992 CB750

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coffee_brake
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#12 Unread post by coffee_brake »

If you were running a more open exhaust and cone air filters (very free-flowing), whichs jets would you change, and how many sizes would you change them?
As a starting place, you know. I don't know in which direction to move.
Jenn S.
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fireguzzi
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#13 Unread post by fireguzzi »

All I can say is that with the extra air flow you want to move up in size. But you prob already knew that. I would change the pilot and main jets. Maybe even move the needle up. But I can't begin to tell you what sizes. Have you looked on a KZ specific forum?
[img]http://i46.photobucket.com/albums/f101/fireguzzi/papabarsig.jpg[/img]

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#14 Unread post by coffee_brake »

Sorry, had some major PC issues...back online now.

Yes, I am working with the Kawasaki Twin Owners Forum, and these guys are great. But the 400 and 440 went through so many versions, each slightly different in the carbs, that finding the way with this one is tortuous.

Also had help from a local vehicle mechanic riding buddy who messes around with bikes, he showed me a lot of stuff, and found my idle circuit not clear. That and a few mods (washer under the needle and bigger secondary jet, pilot screws out 3.25 turns), and I'm idling pretty well off choke but surging.
Right now I am at the "adjust the float levels" stage and it's very hard for me. Seems I can't touch the tangs on the floats lightly enough to make any progress towards getting the right level of fuel. I'm either inches too low or so high it's coming out the overflow tube. I got this tiny little screwdriver and I'm being so careful to bend it just a tiny bit, but it just swings way too far if it moves at all.

Anybody know all about adjusting floats? Cuz I'm no good at it evidently.
Jenn S.
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#15 Unread post by coffee_brake »

New developments....with floats adjust correctly and carbs set up right, it idles but still puffing out the left carb.
Some folks think it may be timing or a valve out of whack.

So...I pulled out the old stock carbs that came on the bike. They were all beat up but I DID see the bike running with those carbs. I cleaned 'em up and swapped all the guts out to the stock carbs. STILL puffing out the left side.

The valves are adjusted to spec. Is it possible that when I lapped the valves, it was not done right? Or, is it possible that the cam chain is installed one tooth off? Would that cause the puffing only on the left side?
Jenn S.
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#16 Unread post by BuzZz »

Being a tooth out on the cam sprocket could throw the valve timing out enough to chuff out the carb alright. Defiantly worth checking out. Does it happen at all RPMS?

Odd that it only happens on one jug though...... is it possible that a valve is sticking or a camlobe is galled or something like that? (bluesky guessing...)
No Witnesses.... :shifty:

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#17 Unread post by coffee_brake »

Buzz I wouldn't know how to tell if a valve was sticking.

But, just for giggles I fixed the boogered-up threads on my second-rate compression tester (I didn't booger them up!) and did a compression test.

On the right (good) cylinder I'm getting 120 psi. On the left I'm getting 110 and the manual says the limit is 109.

As I understand it, low compression results in poor idling and sooty plugs, which is exactly what I'm getting.
And as I understand it, low compression is caused by 1) carbon and sludge buildup on the rings/cylinder walls or 2) a valve not seating right or somehow being out of whack.

Being that this is a fresh rebuild with no more than 20 minutes on it, I don't think the rings are gunked.
I did lap the valves and put in new oil seals during the rebuild. Could I have done that wrong? The valves were checked by a mechanic before I re-installed them and pronounced good, but...were they?

The valve clearance is set correctly, and with electronic ignition, the timing should be correct as well.

Do I need to yank the head again?
Jenn S.
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#18 Unread post by coffee_brake »

Oh, and the cams looked really good, they showed almost no wear at all.
Jenn S.
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#19 Unread post by coffee_brake »

I'm not sure if I've done this right, but here is a video from the camera. You can't hear the carb puffing and hissing, but you can hear the motor missing. Each time is misses, the left carb puffs simultaneously.

http://s195.photobucket.com/albums/z41/ ... I_1086.flv
Jenn S.
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#20 Unread post by fireguzzi »

Ya might want to consider a leak down test. If loss of compression is the problem this can show you where it is loosing it.
And at least you can check that off the list if it is good.
[img]http://i46.photobucket.com/albums/f101/fireguzzi/papabarsig.jpg[/img]

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