What Kind of Noise...

I just purchased my 78 kz400 the other day, and i've been in the process of getting it back on the road.

when i bought it, the guy said all it needed was a battery; so i said, ok cool.

after cleaning the tank and getting a new battery, i tried to start it up and got a godawful noise come from around the carbs. the best way to describe it is a piece of plastic, on its edge, scraping across the floor.

tried to get it started a couple more times to no avail. i also noticed that fuel was leaking from my carbs.

i think i flooded it; but what explains that freakin noise?

ok i got it started, but it doesnt seem to run very smooth.

i went to check out what was up, and found 3 lines from my carbs just hanging loose. uhh....what're these lines?

That all depends on exactely where they are attached at the carbs.
Being that your 400 is a twin, there should truely only be two hoses "hanging" from the carbs - the float bowl over-flow tubes.

If you can either trace where they're attached, or provide a pic, that would be very helpful in telling where they're supposed to go.

As far as the "plastic scraping" noise that's coming from around the carbs.
I'll take a wild guess and say it's probably the starter clutch making it, since your description of it sounds alot like what others have stated hearing when their bikes starter clutch is dying/dead.

therse two lines from each carb, one on the left side and one on the bottom of the bowl.

the guy had them capped off...i found freakin screws in them; sure enough, after backing two of the screws out, fuel started draining from them. the other two didn't have anything come out (vacuum line maybe?)

the fuel was draining from the middle of the the carbs too. I dont know if this was due to the over-flow lines being plugged or what.

did the previous owner fuck up my carbs?


Post edited by: DSMkid05, at: 2007/04/08 20:22

I doubt the carbs are trashed, but those hoses being capped off and the fuel flowing out like that point to at least the float valves possibly being stock/clogged and flooding them out.
= time for a good ol' fashioned carb removal and thorough cleaning.
After the cabrs are cleaned, it'd be a good idea to install an inline fuel filter to help prevent them from becomming gummed up again.

yeah i guess ill have to get on that. this is my first toy with carbs on it, so i have to get used to the whole process haha.

as for the starter clutch; how big of a pain is that bastard going to be? will it still start up ok with the kick start?

heres a little more detailed description of what happens: i press the start button and it tries to turn over, but then makes that horrible scraping noise and just stops. i got it starting one time, but other than that it just repeatedly does that.

Post edited by: DSMkid05, at: 2007/04/08 21:34

so i think my petcock is leaking as well. i took the tank off and had it on the "reserve" position and fuel still dribbled out some. would this explain my overflown carbs?

Post edited by: DSMkid05, at: 2007/04/08 22:02

Sounds like you'll need a petcock kit. Has a couple of o rings and a washer or two. It doesn't take long to do at all.

You probably have found this already, but it's a good site for twins none the less.


www.kz400.com/

You'll here this a lot here, get the clymer manual or the service manual for the bike. It will be invaluable.

The starter clutch is the same on my kz750. It's not terrible to replace, just a booger to get off. Steell gave me a great tip on using the rear axel as a rotor removal tool.

Here's the link to my adventure here

kzrider.com/component/option,com_joomlab...w/catid,4/id,103143/

Good luck!

That noise on my bike by the way was the three bolts holding the starter clutch to the dynamo had sheared off and were scraping against the dynamo itself. Didn't sound pretty at all.

WOW...is all i can say about the inside of these carbs. they are absolutely disgusting...it looks like they've been siting in the bottom of the ocean for a decade or something. there seems to be a calcium buildup of some sort that is ALL OVER the inside of them...

i think i'll just be replacing them. any suggestions? what carbs will fit on this bike?






as for the sound...its disgusting sounding. the description of scraping sheared bolts sounds about right...i guess ill check that out.

doubt you are going to find decent replacement carbs, your best bet is to rebuild yours, carb cleaner, poss kits, and some time

Man, its so bad that parts of it are actually crumbling away when i scrub at them with a toothbrush....thats how corroded and worn out it is. i woudlnt mind if i just needed to buy parts, but right now it seems like i need the whole housing more than anything.