Before I burn this bike.....

saxjonz wrote:

fuel filter may be a problem as well. And the list goes on. Look inside your tank and if you see rust or junk then that stuff has a way of making its way back in to the carbs and like Tri said the low idle circuit is very finnicky. And just any fuel filter won't really work that well. You have to get a really nice one that was designed to work with motorcycles. I have used those two dollar clear ones on my bike and they just don't get the fine stuff. The fine stuff is what mucks up the low circuit quickly.

Thanks man, I'm not using a fuel filter on this bike. the tank looks good, and when I rebuilt the petcock this year the screen was just like new. This is a pesky little problem so yes you're right about the carbs being the issue. I'll have to look through my pile of parts I may have another set around.
Does anyone know if Napa sells seafoam? I've been using the Lucas treatment ever since I got the bike but I would try something else if it works.

Another thought but have you checked the manifolds for cracks. As the rubber gets old it warps and cracks. My carbs also had sticking slides that when I would ride the idle would slide up and then I was constantly having to readjust. If you carb intakes are warped or leak after they warm up the result could be what you just mentioned. Get them off and look at them, if they are cracked you could just put some sealant on the mating surface to the head and that will really help the idle. Check those little plugs on the ends too they dry up and don't keep the air out of the manifold and your bike will run like crap. The head gasket one is problem the least likely scenario. Oh and make sure you put those back on the same cylinders as they came off of. Any air leaks will cause popping.
Born Dead 2 wrote:

OKC_Kent wrote:

Until someone else chimes in with another suggestion have you tried new fresh gas?

Fresh gas and a few tanks of Seafoam treatment. Adjust the idle up a bit.

Yup, fresh gas actually 2 tanks later. Haven't tried the seafoam yet. As far as adjusting the idle, When I adjust it up to 1100-1200 rpm's it'll idle fine until it warms up and then it goes up in idle and I have to adjust it back down.
doesn't seem right to me.

saxjonz wrote:

Another thought but have you checked the manifolds for cracks. As the rubber gets old it warps and cracks. My carbs also had sticking slides that when I would ride the idle would slide up and then I was constantly having to readjust. If you carb intakes are warped or leak after they warm up the result is what you just mentioned. Get them off and look at them, if they are cracked you could just put some sealant on the mating surface to the head and that will really help the idle. Check those little plugs on the ends too they dry up and don't keep the air out of the manifold and your bike will run like crap. The head gasket one is problem the least likely scenario.
Born Dead 2 wrote:

OKC_Kent wrote:

Until someone else chimes in with another suggestion have you tried new fresh gas?

Fresh gas and a few tanks of Seafoam treatment. Adjust the idle up a bit.

Yup, fresh gas actually 2 tanks later. Haven't tried the seafoam yet. As far as adjusting the idle, When I adjust it up to 1100-1200 rpm's it'll idle fine until it warms up and then it goes up in idle and I have to adjust it back down.
doesn't seem right to me.

Well intake boots are new this year, head gasket was done last season, exhaust gaskets are new, pipes have no holes or cracks. And since this problem just appeared lately, I'm assuming the carbs are the prob. Also the plugs are a nice tan color so it seems to be running fine, just shitty at idle.

Supposedly Seafoam was made available in Canadian stores (NAPA, etc) a couple of years ago but your results may vary so you'll just have to phone around

But if the bike ran great last year and you put a few thousand miles on it maybe the carbs are good. For sure at least put a filter on it even though you have one in the tank. After twenty-five years of being around the tank may have some stuff in it. If you have cv carbs which I know nothing about your diaphragms may be leaking. Good luck and let us know what happens.

Maybe mised something but two things jumped at me in reading your post...

1)"Running with choke on..."

2)"it does pop through the exhaust a bit when I decel."

Both of these items tell me your running too lean...

Jut a thought...

What do your spark plug insulators look like?

OMR

Old Man Rock wrote:

Maybe mised something but two things jumped at me in reading your post...

1)"Running with choke on..."

2)"it does pop through the exhaust a bit when I decel."

Both of these items tell me your running too lean...

Jut a thought...

What do your spark plug insulators look like?

OMR

Hey OMR,

Thanks for the response, I thought it was too lean also, but the insulators are in good shape and are are a darker tan color. I don't run it with the choke on. I start it with it on full, bring it down half way and have to give it a bit of throttle till I pull the choke off and still have to give it some throttle. After it warms up it will idle, just takes about 20 mins of riding to get there.

Sounds like my bike if I hit reserve and suck all the trash in the carbs. An inline filter is crucial to filtering the trash from the tank. Like has already been pointed out the tank is aged somewhat and you can not see all around inside without cutting in half. Even if it looks clean it probably is not. Get the carbs clean one more time and clean the tank at the same time then run a fuel filter and you should be good to go. Always be wary of hitting reserve unless you KNOW FOR SURE the tank is clean. My .02 cents

if you live where there is a greg's distributing try them as they now carry it as well. as far as cleaning the carb's properly every symptom you describe sounds to me like partilly plugged pilot circuits the best way to get those clean is with quality spray carb cleaner like c.r.c don't use any of the junk crappy tire sells also as been mentioned peices of copper wire to follow along the passage after the carbcleaner has been used then most important of all blow compressed air thru all the passages and make sure your getting air flow all the way thru including the passage in the float bowl. also use a decent filter in line get as good a quality as you can find.

timebomb33 wrote:

if you live where there is a greg's distributing try them as they now carry it as well. as far as cleaning the carb's properly every symptom you describe sounds to me like partilly plugged pilot circuits the best way to get those clean is with quality spray carb cleaner like c.r.c don't use any of the junk crappy tire sells also as been mentioned peices of copper wire to follow along the passage after the carbcleaner has been used then most important of all blow compressed air thru all the passages and make sure your getting air flow all the way thru including the passage in the float bowl. also use a decent filter in line get as good a quality as you can find.

Thanks man, there is no Greg's around here so I'll try Napa/UAP. Also I'll upgrade my carb cleaner since I did use the Crappy tire stuff. I know it's shit but all I had around that day. I'll also use the ole' guitar string trick as mentioned and an inline filter. Man I love carb's!!!!:woohoo:

once you understand them it comes easy it just getting the experiance that's painfull. i wish i could just ride around all summer long doing carb repairs for you guy's but that cant happen once. when you get this all fiqured out the next bikes will come easymost times you will find if the bike has been sitting for any length of time the carb's will need to come apart and be cleaned so i always do that first thing when i buy a different bike.

timebomb33 wrote:

once you understand them it comes easy it just getting the experiance that's painfull. i wish i could just ride around all summer long doing carb repairs for you guy's but that cant happen once. when you get this all fiqured out the next bikes will come easymost times you will find if the bike has been sitting for any length of time the carb's will need to come apart and be cleaned so i always do that first thing when i buy a different bike.

Yeah, I'm starting to get the hang of carbs. Got 4 Kz's in my possession now. My 76 900 chop is my baby she never act's up and I ride the balls of that bike. This ZN was a rescue bike, I didn't really want it due to the shaft drive, but $200 and alot of pain later I guess I can't really complain. They're old bikes so they just need to be maintained.
Thanks again for all of the support guys, I'll let you know how it turns out.