Hard Starts When Cold

[Hoomgar]

My 550 runs great once I have it running and warmed up. It will also refire just fine once it is warmed up. And when you ride it is seems to be running very well. I can't complain.

But when you let it cool back down then it will not start again no matter how hard you try. You will drain the battery trying. It spits and sputters and actually fires but stalls as you cannot get it to rev up. The only way to get it started when cold is to spray it with a shot of carb cleaner or God forbid a shot of starter fluid. I know that doing this is not good for it so I would like to fix it but am not sure what to fix as I don't know what is broke!

The only thing I want to do to it yet is put a new air filter in it as the one that is in it looks quite old and dirty. I have one on the way. So maybe that could be it? Or is it going to be more complicated than that?

I want to get it to where it will start correctly so that I can commute to and from work on it without having to strap a can of spray on the back.

Thx guys

[Anonymous]

carbs.

are you running stock air box,carbs,and stock exhaust?
any mods?
what do your plugs look like? very white?-lean?
when your bike is cold try pulling out the air filter and almost completely closing off the intake-- thus REALLY richening the mix.-then if it fires up get to idle by playing with choke lever.
these old jap bikes choke get clogged/crudded up, also the air screw and carb boots cause problems.- try above first - good luck- otherwise ride it over--- I'll go thru it. (just kidding)

CSH.
78 & 79 gs1000e, 70'tri 650 tiger.-- yup ride em all.

[Hoomgar]

It's all stock 100%. 82 KZ550C3 LTD.

It sat for quite a while so I thought maybe the carbs would be gummed up but then it wouldn't run right would it? I mean it runs all but spot on once you get going. And it idles great and everything. So I figured it wasn't carbs. But maybe I am wrong. Wouldn't be the first time for that

If it is choke clogging and or air screws I will need more advice for sure!

Thx for the reply. I'll look at this tonight.

[lhanscom]

If your idle jets are clogged you could have this problem. I have this problem with my pods when trying to start in cold temps, like 20 degrees. When it's warm out it starts easily. I figure it's just not 'choked' enough for the cold temps, and it runs great once warmed up. One thing that may help too is richening up the mixture screw a bit, I plan on doing that to fix mine.

[Hoomgar]

I have never done anything like that. How do you know rich/lean or where your actually at vs where you should be?

[lhanscom]

I'm working off the fact that cold air is more dense then warm air. Since my bike starts fine in warmer weather, I'm assuming that it is a touch lean for starting in the cold weather. I believe this effect is exagerated due to my pod filter. As for 'where you should be' I'll just back the screw out a turn and see what happens. If it doesn't run right, I'll reset the screw. As you can tell it's a very delicate procedure. :roll:

[Hoomgar]

hmmm, sounds scary 8O
I don't even know what screw to turn let alone how much.
I am going to have to read up on this in the manuals tonight.
Maybe I will just brave it and rip them off and reset them up.

Or

Maybe I will chicken out as I always do and pay Joe 50 bucks
to set them up for me

I just don't have the 50 right now and he is crazy busy and I don't
want to wind up waiting on my carbs to my only running bike at
this time of year so I am between a rock and a hard place on this one.

Doh!!!

[Pete's GS]

Actually, the bike can run right when warmed up but still be hard to start. My GS550 wouldn't start without starter fluid but then it ran fine. I pulled the carbs-ugh!-and cleaned them according to the directions in thegsresources for cleaning CV carbs and the choke circuits worked again! Those dang orifices are so small in CV carbs it doesn't take much in terms of varnish or stray dirt to plug them up. (I'm assuming your KZ is running CV carbs since they pretty much became de rigeur in UJMs by the early-80s.)

[Hoomgar]

Actually, the bike can run right when warmed up but still be hard to start. My GS550 wouldn't start without starter fluid but then it ran fine. I pulled the carbs-ugh!-and cleaned them according to the directions in thegsresources for cleaning CV carbs and the choke circuits worked again! Those dang orifices are so small in CV carbs it doesn't take much in terms of varnish or stray dirt to plug them up. (I'm assuming your KZ is running CV carbs since they pretty much became de rigeur in UJMs by the early-80s.)

I really don't know. I know it's all stock. So whatever came on the 82 KZ550C3.

Looks like I am in for a good carb cleaning then. If I don't turn or adjust anything It shouldn't get knocked out of whack then right? I don't want
to get into setting them back up if I don't have to because I have no idea what that involves and am sure I don't have the tools I need to do it.

But if it comes to that then so be it. I am no afraid to, just don't want to get stuck without a running bike.

[lberkhei]

Sounds like the same thing I went through with my 750. Started and ran fine when warm, but awfully hard to start when cold. Even though the dealer from whom I'd just bought it claimed to have done carb work on it, with a little checking, I figured it had to be the carbs. So I took them apart, found clogged passages, etc. Now I just have to get them back together... :? (been apart over a year now...)

[snowbeard]

exact same problem here, GS650G that starts only with fluid after a couple days sitting. haven't had enough cold days since I got it running again (three weeks ago) to say it's from "cold" but I would imagine that doesn't help. the bike has sat for long periods, and when I got it had to pull the carbs a few times to clean and make some new gaskets on the bowls, finally found the idle screw, but haven't dinked with the fuel mixture screw (same deal here too, what the heck is that!?!?) but I know it's running rich-->my buddy thinks I'm gonna blow up if anyone lights my exhaust!!! 8O

Sorry I haven't anything to offer but commiseration, but if I find out I'll let you know!!

[Hoomgar]

Sounds like the same thing I went through with my 750. Started and ran fine when warm, but awfully hard to start when cold. Even though the dealer from whom I'd just bought it claimed to have done carb work on it, with a little checking, I figured it had to be the carbs. So I took them apart, found clogged passages, etc. Now I just have to get them back together... :? (been apart over a year now...)

Yeah.... thx a lot Lynn, that's very reassuring

LOL, that's exactly what I don't want to have happen to me!

[Hoomgar]

That's OK guys, I know one of the vets will be along soon to impart their wisdom on me. I am counting on it

In the mean time I guess it can't hurt none to pull the carbs off a while and poke around.

What's the worst that could happen? 8O

[Anonymous]

my 81 750 was getting harder and harder to start as time went by.it was always when it was cold too. one day it wouldn't start at all- turn over okay but no starting. so i took the carbs off. went thru about everything. cleaned the jets,checked the floats, diaphragms, etc etc..except- for some reason i decided to blow into the vent tubes. i couldn't believe ALL the crud that came out of the little oriface in the carb body. at least two of the carbs spewed all kinds of crap. the right sidetube i could hardly blow any air into at all. so now when it gets a touch hard to start i just blow on the tubes. yes, gas comes out of the bottom of the air filter body but the old gs always cranks right back up. and it gives me pleasure thinking that i'm blowing crud out too! if i'd have known this before i wouldn't have had to take the carbs off-at least for that problem. at least thats my experience.

i live down a bumpy sandy crappy road. so i think i gather more sand in places than most who don't have a road like this one.

[Anonymous]

I find mine dosn't like cold starting on avgas *L*