2000 gpx250 w/ pitted & tapered cams 23,000km

howdy everyone,

Just recieved the bad news that my baby's hearts on the way out,
looking for donors with information about others with similair
condition.

She's a 2000 model and has travelled 23000km, after the last service
it was announced to me that the cams have become pitted and tapered,
shes been with me for 5,500km and i've been pretty gental, red-line
once, gone above 10k seldom, mostly running between 6k and 4.5k to and
from uni. Bought second hand at 17,500km, currently chasing previous
owners service history.

I've contacted Kawasaki australia and the parramatta dealer, both have
said that this is not a common problem and a Kawa Aus techo suggested
it was probably an early maintenance issue. Kawa parra also told me
that i could come in and they'd take the vin and my phone number and
see what they could do.

But with hardly any km's done i'm a little suss that this happened at
all,
especially since a local mechanic had the same problem in his late
model zzr250 cause a rocker to disintegrate his engine (under
warranty).

If anyone has any info or common experience in this matter i would be
most happy to hear it.

Thanks in advance,
-Glen

 

Exactly the same thing happened to me at 40,500kms. 1 inlet cam lobe
was totally screwed, it's rocker badly damaged & the exhaust cam had
pitting. 3 of the other rockers had the hard facing worn away as well.

In this case however, the top end damage was because of maintenance
issues with the previous owner. It would have been luckly to have had
1 valve clearance adjustment in 40,000km's. The thing that finally
killed the top end, was diluted oil from fuel in the sump.

You should be able to pick up a set of cams & rockers from the
wreckers for around $200. Replacing them is not that hard - you just
need the right tools, a service manual & patience.

Forget about new parts, as I was quoted nearly $400 per cam $55 per
rocker. At that rate you can pick up a second had low k's unit for
$750 - $800.

I got mine from one of the aus.moto regulars (Hi James M !) & also had
a spare EX250 engine last time I spoke to him. E-mail me if you want
more details.

David.

 

It certainly feels like that after several days on the sushi,
best to cut down on the wasabi a bit and seek alternative sources
of dietary fiber.

-----sharks

 

It sounds like either the oil was contaminated, or changed too
infrequently, or both. My '88 model is now up to 132,000km and the
cams and rockers are still in good shape[1]. I bought it 3 years ago
with 43,000km on the clock. The manual says to use SF grade 20W50
oil[2], and change it along with the filter every 10,000km. I reckon
that's far too long of an interval, especially since it only needs 2
litres (ie. $5) worth of oil. I change mine every 3,000km, and I
replace the filter every second change (ie. every 6,000km).

I'd recommend buying a new set of cams (and rockers if required) from
a wrecker, and telling me your address so that I can send you a CD-ROM
with a copy of the service manual on it. It's not too difficult to do
the job, and you'll learn a bit along the way.

Alternatively, if you plan on buying a replacement motor I'll give you
$100 for your old one. ;-)

Nah, the most common cause of demise for these motors is a big-end
failing at a high mileage.

Rockers don't come loose due to pitted cams, but improper assembly can
get them floating around in the motor (as I discovered yesterday).


BTH
[1] I know that for a fact because I spent a few hours last night
closely examining them!
[2] I use the $10-for-4-litres Valvoline or Castrol stuff. Even I'm
not tight-fisted enough to use Home Brand!

 

Thanks for all the advice everyone!!

I've taken it to a second mechanic and if its ratshit i'll ask him to
put some new (2nd hand) ones in for me.. but if they look like they
can last for another 6000km i'm going to have a go at it at chrissy.

jeb from ninja-250.info suggested that i use an oil with zinc (donor
metal), any idea which these might be?

checked the oil rating in the service manual, (Thanks for the offer
but i bought both a while ago..) 10W-40 10W-50 20W-40 20W-50. Any
benefits of using motul or silkolene over castrol or havoline?

so busted cams alone won't destroy my engine?? any description of the
sound they make about that time?

BT, nah i'm too tight to splurg on a new engine, I'll keep it in mind
tho

would i be risking major engine damage running on fairly worn cams?
(i'm imagining a valve getting opened at the wrong time...)

Don't know about the japanese, but from the message i got from the 1st
mechanic, i was shitting bricks that my engine was going to detonate
next time i rode it.

Advice on keeping worm cans alive??

 

The damaged cam lobes could damage your rockers also and then you have more
parts(and more $$$) to replace. When they're buggered, they're buggered.
They could be reclaimed by having the lobe surfaces built up and reground by
a camshaft place, but i wouldnt know how the cost would compare the original
replacements.

Valves won't open at the wrong time, they'll just open less and less if
the lobes wear down extremely, you should notice the noise though as the
clearances loosen.

The earlier you fix it, the less it is likely to cost.

--
Al

http://www.users.bigpond.com/pennykid/alan/index.html
"The highest form of life in the universe is Man and the lowest is a
man who works for the post office." - Holly

 

What he said. Fix it soon, and forget about resurrecting your
existing cams - it's much cheaper and easier to get good used parts.


BTH

 

The earlier you fix it, the less it is likely to cost.

fair 'nough..
just got it back from another mechanic (micheal at c/hill mcycles,
charged me less than his quote), turns out the case hardening had come
off (with a bit of pitting on the middle of the lobes), so i'm going
to put a used set in at chrissy.

Thanks for the help.

 

The earlier you fix it, the less it is likely to cost.

fair 'nough..
just got it back from another mechanic (micheal at c/hill mcycles,
charged me less than his quote), turns out the case hardening had come
off (with a bit of pitting on the middle of the lobes), so i'm going
to put a used set in at chrissy.

Thanks for the help.