kz750 ltd 1981 cam chain rattle

hi kzriders

we've just restored a kawasaki kz750 ltd
1981. the bike runs well, the cam chain is noisy as usual. there is a oem kawasaki
cam chain tensioner fitted.

the weather in the uk is freezing. i went to
start my bike and the cold seems to of effected the cam chain, it has gone really
noisy.

will the ape tensioner be suitable for my bike please?

will it cure the cam chain rattle?
i think because the weather is freezing cold,
the cam chain has contracted and is creating the noise.

in the summer the bike runs fine, a slight cam chain rattle. in the winter
it's really loud.

is it best to change the oem cam chain tensioner
to one of the ape manual ones please.

please will you send me some sunshine and
warmth, this bike doesn't work well in the winter.
it's freezing, but not that cold -1-2.

could the engine oil be part of the problem?
summer oil in a winter environment?

the bike has only done 8000 miles.

many thanks

angie

Summer oil?? What oil do you have in the engine?

thanks for your reply ed!

i bought a case of gulf power trac 4t
semi-synthetic sae 10-40.

is ok for winter too? you guys have better
weather!

thanks for your advice y'all!

regards

angie

Cam chain is steel, case, cylinder (except for iron liner), and head, are aluminum.

Aluminum shrinks a whole lot more than steel.

It's probably the tensioner binding up. You could try taking it off and cleaning it, but the APE tensioner works too.

hi thanks for your message!

i've never taken a cam chain tensioner
off before. i can see a couple of bolts.
what i'm concerned about is messing up
the cam chain timing.

i don't know how to do this.
any instructions on how to service
and stop the critter from binding up is
greatly appreciated.

many thanks riders!

regards

angel

10w40 oil should be fine for winter and summer. Ed

Your bike will have a Cam Chain and a Primary chain. The Primary chain can be noisy as well, as there is no tensioner on it. If the Idle is low and a bit rough it will make the Primary chain rattle a bit until warm. Hows the Idle when starting in the Balmy 0c weather? Is it low and a bit rough till warm? You may find the Idle mixture screws need to be turn out/ counter clockwise, another 1/8- 1/4 turn for the colder weather.
Otherwise the cam chain tensioner is fairly simple to remove and service. I would rotate the motor to the 1-4 T mark before removing. The large Cap, 17mm socket head nut, is to be at least loosened if not removed while in place. Then its just the 2 10mm headed 6mm bolts that hold the body in place. It can be taken out with the carbs in place, but is much easier to do with them out. But it will remove and install with the carbs there. What you want to look for is where the two wedges come together, these need to be smooth no burr's. Then the service manual will have the correct spring free length, if they are worn/ clasped, it won't tension properly. Or you could possibly still have the earlier model Tensioner. Look at the picture and see the two.

hi motorhead

long time no speak!

many thanks for your really informative
posting. i'm most grateful.

since i last communicated on here.
the aftermarket exhaust 4-2 went back
with a manufacturing fault for side and
main stand clearances. i managed to find
an ok oem kz 4-2 exhaust with all clamps etc.
boy i managed to install this eventually.
i used small plastic boxes, left & right to
support the mufflers and then secured from
front to rear. the bike worked well in the warmer
climate. a slight chain rattle.

the weather has gone really cold.
the bike is in a garage and it hasn't been
ridden due to the ice on the roads.
the bike is on a trickle smart charger.
i primed the fuel, choke and
i tried to start the bike.
the cam chain or other chain
sounded very loud? i phoned my
new garage and was advised
'as you now live on the sea coast,
all the classic/ carbed bike suffer greatly
here, it will be ok in the summer!'

oh great, i thought.

is the bikes metal contracting with the
severe cold effecting the bikes engine?

does severe cold effect the chemistry
of the fuel? stopping combustion etc?

eric, the bike and i need to live
in a warmer climate!
As Loz, says, just simply remove the 2 bolts and remove tensioner. Back off new manual tensioner and insert in hole, tighten 2 fixing bolts.
Gently wind in the tensioner bolt (assuming you have an APE maunual tensioner) until you feel a little bit of resistance, then loosely lock off.
Start engine and allow to run up to temperature and liosten for any rattles, if all is quiet then leave it. If it rattles still, just tweak the bolt inwards until rattle stops.

Did this on my olf VFR Vtec as Honda tensioners are sh!te and keep failing, then put considerable mileage on bike without ever needing to adjust again.
many thanks motorhead.

hi motorhead

so sorry for the mixed up message.
my iphone 'cut copy & paste' crashed
and copied part of lols posting.

i've just found a new product called
silkolene pro fst. this is being used by
the uk bikers whose bikes carbs are icing up.
my friend told me a story of a biker she knows
whose bikes carb froze up on a british
motorway and obviously the bikes engine
stopped frighteningly. luck enough,
not much traffic and he coasted inton the hard
shoulder.

this product 'valvolene pro fst' cured
the carb icing up problem!
i've now bought some and put some
in eric, the bike.
100mls to a gal!

does it freeze in the usa?

best wishes and thanks

angel

Hey Steel horse glad to see your still at it

I have ridden my bike as low as 0 degres metric but she doesnt like it I have also noticed if i dont ride her for a while i notice either cam chain or some other knock rattle or change in sound

before i started changing anything run her a little more often see what noises change
cause when I ride miine all the time they seem to go away

Wow; it must get rather chilly in merry old England! Gasoline freezes at a temperature between -40 and -50C (that's -40 to -58F). I doubt that I am man enough to ride my motorcycle in that environment, but thankfully I'll never be tested. :laugh: :laugh: :laugh: :laugh: I would think the motor oil might not flow very well at those temps either without the bike being attached to some sort of heater when not running. Are you sure the fuel hasn't been corrupted with water?

Usually carb icing isn't the fuel. It's from water condensing as it goes through the venturi portion of the carb (pressure drop). I'd think the engine would keep the carbs warm enough to keep that condensation from freezing though, and I'm not sure how a fuel additive would help either way, since it's not the fuel freezing.

It definitely freezes here in the US. I've looked at some weather stats from a couple parts of the UK. It got colder in Arizona (granted I lived in the mountains) than in the UK, nevermind you nuts living up in Minnesota.