How much warm-up time?

Kawasaki's are pretty cold-blooded. Take a little longer than say a
Honda/Yamaha to warm up. I give my 2000 Kawasaki Drifter 3-4mins to
warm up to operating temperature. I have to do this even in summer to
keep it idling and shifting properly. Is this normal? How long do you
guys typically let your bikes "warm" before pulling off?

 

I gave my Voyager XII 30-60 seconds, depending on OAT. The best way to
warm up any engine is to run it slowly and lightly loaded. Prolonged
idling generally isn't a good thing for a cold engine. You don't want
to take off WOT and rev to redline either, but moving off slowly and at
light throttle for a mile or two warms the engine much more quickly than
idling and it also helps get youo where you are going.


Matt

 

My routine is to start the bike with full choke, and wait till it
starts loping because its over-choked (not long - maybe 10 sec). Once
I've eased the choke in enough to stabilize idle, I don my helmet and
gloves (maybe another 10-15 sec). At that point, I'm off. I try to
take it easy for the first Km or so, while continuing to push the
choke in. Once the choke's right off, I'm in full "give 'er" mode
Note - to reply by email, please reformat the addressee (should be pretty obvious)

 

I agree with Matt, the best way, I find is to choke for 20 to 30 seconds and
then lightly loaded for the first mile or so. Always worked for me.

Bill
'84 CB750SC (Nighthawk)

 

As soon as it will idle without the choke. Usually less then a min. I
have a 2002 Kawasaki Concours. As mine is an inline 4 instead of a
v-twin it may differ, but 3-4 nins is too long.

 

Slightly different perspective, from a Desmoquattro Ducatista:

Fuel injected, so there's no choke, but there is a "cold start
lever" which is a throttle. I don't use it. I use as little
throttle as possible when starting, and hold it until the idle
comes up a bit (a few seconds). I let it idle for at least 90
seconds, which is a worst-case estimate for the desmo rockers
to achieve full lubrication. I may then apply the cold start
lever and raise the idle to 2000. I wait until the coolant temp
is 114 F before riding, and ride gently until above 146 F.

Lots of eejits let their bikes idle fast when cold -- Italian
machinery rewards this the need for expensive repairs.

-kudzu
Ducati 749

 

This thread reminds me of when I attended a series of group guitar lessons.
At the beginning of the first session, the instructor asked the group,
"What's the best way to tune a guitar?" After a number of the participants
offered their favorite techniques, the instructor then asked which of these
was the best. The answer, he said, is the one that works best for both
the guitar and the player. In other words, there is no one best way.

And so it is with motorcycle warm-up techniques. If you listen, your bike
will tell you what it needs and you and your bike will find the way that
works best for you both.

 

Italian machinery rewards any usage at all with expensive repairs!

Matt

 

Except I've always owned Kawasaki's and I don't speak Japanese...


Matt

 

Warm weather (or as warm as it gets in the UK) : start the engine and ride
off immediately.
Cold weather : start engine then put on helmet/gloves and ride off.

So, zero time to maybe 30 seconds depending on the weather. Actually the
owner's handbooks for my last two bikes (Kawasaki ZR7S and the Honda
CBR600F3 which I have now) both specifically said NOT to let the engine warm
up at idle, better to just get on with it.

SteveM

 

You can warm it at idle. It just takes longer, runs the engine longer
with a rich mixture which makes the plugs more prone to foul and the
extra gas tends to dilute the oil film on the cylinder walls and lead to
higher wear during warm-up. May not be a big deal, but why not just
hope on and ride as soon as it will take throttle?


Matt

 

ack...

i just took apart and cleaned the carbs on my 75kz400d, and put back
together, and the bike idles much better now (lower than 4000 .

but, it doesn't want to start w/o a little throttle (which my manual
says i don't need). i ran it for 5 min tonight and had it idling nice
around 1200-1400, but when i took off the choke it just up and died.
also, pilot screws seemed to have little/no effect when screwed all
the way in to out.

all of this makes me think my pilot system is borked/clogged. my
pilot jets looked dirty under their little black plug thing, but i
couldn't get them out easily and didn't want to damage them...

does this seem like a fair assessment?

 

Shouldn't be much different. The biggest problem is that the fuel
doesn't atomize as well when the carb, intake and head are cold, and
doesn't fire as well when the spark plug and cylinder, heard and piston
are cold. This means that not every compression stroke results in a
fire being lit. This means that unburned fuel is washing around in that
cylinder until the next compression stroke. That is why your idle is
often lumpy when the engine is cold, or why it won't idle at all. If
every 3rd or 4th spark isn't igniting the charge, it has an affect on
your idle.

True, but more air gets sucked in also and the fire is hotter when you
have the throttle opened more so the chance of firing on every spark is
much higher.

If it will idle steadily after 10 seconds, then it is ready to hit the
road ... gently.


Matt