Before I burn this bike.....

Ok, here's the long story shortened. last year I rescued a 84 zn700 from a guy who had it sitting outside for few years. Bike wouldn't fire, brakes didn't work and so on. So spent a few weeks on rebuilding the top end, rebuilding the calipers and painting the god awful color it was. Got it all done bike ran great last season with only a few minor electrical problems, but everything else good. So this year I put new battery,new plug ends cleaned carbs checked valve clearances, timing all in spec's, but now when I start the bike she starts, doesn't want to idle with choke on full, have to take choke down to half and hold the thottle open a hair so it doesn't stall. I know these are cold blooded beasts, but when I take the choke off, when it's warmed up I still have to keep the throttle open a bit to keep the RPM's up. after about 20 minutes of riding and coming to a light it'll idle without the throttle being opened, but it does pop through the exhaust a bit when I decel.
So my question is what the hell am I not seeing here? Everything is clean in the carbs, new battery, plugs, wires, everything is in spec, cam chain is rattling a bit, but I can't see that being the culprit or could it be?
It seems to be in the pilot circuit somewhere.
Anyone who has seen or had this problem?
Thanks in advance
BD

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.

your idle circuits may have gotten gummed up/clogged and a good cleaning of all removable parts in the float bowls..in a little tub of carb cleaner two inches deep six around and a fine strand/strands of copper wire to pass through orifices carefully so as not to break off wire in a jet....you'll need a good diagram of you EXACT carbs a tiny flat head and a blow up of where the little circuits are tucked away...also spraying the passages out and resoaking thrttle bodies a few times is important...the choke issues and the popping are my clues to the idle circuits being clogged.....good luck...just my guess....if it is and you pull the carbs and get em squeeky clean you'll notice a dramatic effect....

Have you tried running Seafoam through the gas yet? You might get lucky.

Lol Kent beat me to it. Seafoam is good stuff.

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.

trianglelaguna wrote:

your idle circuits may have gotten gummed up/clogged and a good cleaning of all removable parts in the float bowls..in a little tub of carb cleaner two inches deep six around and a fine strand/strands of copper wire to pass through orifices carefully so as not to break off wire in a jet....you'll need a good diagram of you EXACT carbs a tiny flat head and a blow up of where the little circuits are tucked away...also spraying the passages out and resoaking thrttle bodies a few times is important...the choke issues and the popping are my clues to the idle circuits being clogged.....good luck...just my guess....if it is and you pull the carbs and get em squeeky clean you'll notice a dramatic effect....

I did clean the carbs this season already and put all new orings and seals in them. Thanks for all the responses. Also here is a stupid question for my fellow Canadian wrenchers. Where can I get this seafoam you speak of?
Thanks again.

the idle circuits are tiny/and out of the way and often get missed on inspecting for a cleaning...you may want to see a blow up and dble check that you got to em...i also had done cleanigns and adjusting and was not seeing em till my same problems arose...my 2 cents

I had this problem once with a fuel filter too close to the carb inlet. Under full/half choke, the fuel would froth in the small gap between them.

Make sure (clear hose) that a nice thick stream of fuel is getting in there under full choke.

... and that there is absolutely no air/fuel leaks anywhere possible in the system.

Cheers, n' good luck!

Fellow Canadian wrencher.

trianglelaguna wrote:

the idle circuits are tiny/and out of the way and often get missed on inspecting for a cleaning...you may want to see a blow up and dble check that you got to em...i also had done cleanigns and adjusting and was not seeing em till my same problems arose...my 2 cents

Thanks man, I'll tear the carb down again and go through it. Also I am going to run the seafoam. Where can I get that in Canada?
Thanks again

I have had nightmares with bikes that have been sitting for years. I have torn a set of 26's off of my bike and cleaned them at least 20 times and even paid someone else to do them for me a couple of times and it would run great then poof. Same problem till I got some other carbs. Carbs are not always so easy to clean if they have been sitting forever.
Popping is carb related, possibly electrical and also even headgasket like my 80 z. I would accellerate hard and then when I would back down it would pop. I noticed a small oil stain on the block and to my dismay I found that the PO had overfilled the oil at one point which is about the only effective way to blow a kaw gasket. :huh: :lol:

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.

There is another thing called ring free or whatever and you should be able to find that stuff in most bike shops. It works really well but I would make sure to change out the oil after you have run a tank of that stuff.
Born Dead 2 wrote:

trianglelaguna wrote:

the idle circuits are tiny/and out of the way and often get missed on inspecting for a cleaning...you may want to see a blow up and dble check that you got to em...i also had done cleanigns and adjusting and was not seeing em till my same problems arose...my 2 cents

Thanks man, I'll tear the carb down again and go through it. Also I am going to run the seafoam. Where can I get that in Canada?
Thanks again