Puff of smoke

Kerrigan · #1 PostAuthor: **Kerrigan** » Sun Sep 03, 2006 10:54 pm

Some advise required please.
My Z900 emits a couple of puffs of blue smoke on start up from cold.....
It does not smoke at all after about 20 seconds and as far as I can tell is not smoking while riding.
I had a look at the plugs.
The two outer ones were quite sooty and the two inner ones were a little black but had a nice dark brown centre.
As the bike has probably spent a period standing at some point in its past, I assume it could be the valve seals...
Is this a major issue that should be looked at straight away, or might it improve with more use and does it matter at all - as the bike runs very well (indicated 120mph the other evening!!!not bad for an old girl, not me - the bike!!!)
Also, can you sort the valves with the engine in situ?

Kerrigan

#2 PostAuthor: **chrisu** » Mon Sep 04, 2006 10:17 am

could well be the seals - they do harden after a while - if the heads not been off then thats sounds most likely.

head off while engine in the frame is dead easy - but if you've not done it yourself before I'd suggest getting someone else to do it for you over the winter. Head off, Cams out, Valves out, replace seals, grind valves, replace, redo cam timing etc etc.

HTH

rickman CRR · #3 PostAuthor: **rickman CRR** » Mon Sep 04, 2006 10:52 am

From the french Z1 link page.

Removal of valve stem seals without lifting the head!!

http://www.900z1.com/pgs/imgs_t&a/joints_de_queues.pdf

seems like a lot of bother to me. If you lift the head you can always check other things out, like valves seat wear etc. Still, interesting engineering solution

phil churchett · #4 PostAuthor: **phil churchett** » Mon Sep 04, 2006 6:06 pm

It all depends on how much it bothers you. My own A4 smokes a bit on start up, but not enough to warrant taking the top end apart. I would think to be honest there are very few Zeds, even those that have had a complete motor strip, that don't smoke a bit.
As the old saying goes; if it aint broke, don't fix it!

#5 PostAuthor: **chrisu** » Mon Sep 04, 2006 6:31 pm

is there an echo in here ;-)

phil churchett · #6 PostAuthor: **phil churchett** » Mon Sep 04, 2006 7:10 pm

Have already asked Chris why my posts usually come up twice.
He reckons i am too enthusiastic with my button pressing!

phil churchett · #7 PostAuthor: **phil churchett** » Mon Sep 04, 2006 7:12 pm

I definitely only clicked once Chris, honest!

Padders · #8 PostAuthor: **Padders** » Mon Sep 04, 2006 7:41 pm

Agree with you on the "if it aint broke don't fix it" a bit of smoke at start up would not justify a head off for me.

Jumbo · #9 PostAuthor: **Jumbo** » Mon Sep 04, 2006 8:14 pm

I am sorry to say that method looks very dodgy. There is a good chance of damaging the threads for the plugs and I would say a good chance of dropping a valve into the cylinder. Also you will not be able to see the condition of the valves and the result of that has been seen in another posting with pictures !!

I am an Engineer also !

DogsbolloxofZ1B · #10 PostAuthor: **DogsbolloxofZ1B** » Mon Sep 04, 2006 9:38 pm

Use a more viscous engine oil, may lessen the effect for a few years.

Kerrigan · #11 PostAuthor: **Kerrigan** » Mon Sep 04, 2006 10:07 pm

Thanks guys....
I don't think I'll bother unless the problem gets worse.

rickman CRR · #12 PostAuthor: **rickman CRR** » Tue Sep 05, 2006 8:52 am

I agree with you Jumbo but interesting none the less. I suppose it just shows it could be done.

Puff of smoke

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