Back on the Road
shampson
shampson at gmx.co.uk
Fri Nov 7 08:57:28 PST 2008
Thanks for the reply Steve,
Changing the valve seals has worked as I've done over 100 miles since the rebuild with no problems. Mind you I've done 100mph and the problem appeared after a blast 125mph.
I already had muzzy block off plates installed 8 months ago and all the clean air gubbins removed. I never checked or removed them from the Head Cover as I did'nt think they were the problem. However your right and oil can get in that way. Fortunately or unfortunately after spending all that money, it looks like the valve seals were the problem.
If it reappears in the future them gaskets are the 1st thing I'll check.
Cheers
Steve
-----Original Message-----
From: blackgpz at rochester.rr.com [mailto:blackgpz at rochester.rr.com]
Sent: 07 November 2008 13:51
To: gpzlist at micapeak.com
Subject: Re: Back on the Road
Steve,
Congrats on completion of the rebuild. Probably could have saved you a lot of time and money because the smoking problem was not related to anything you looked at and I didn't see where you addressed it. There is another way for oil to get into the exhaust system and cause smoking, through the KLEEN Air port that passes through the cylinder head and ends at the exhaust port. Typically, the "figure 8" gaskets under the valve cover fail, allowing oil from beneath the valve cover to enter the exhaust system just past the exhaust valve. This will give you the white cloud and as you said," performance did not seem to be impaired". This was the key as you know the engine could not be burning that amount of oil without seriously affecting power. Hopefully you installed new "figure 8" gaskets under the valve cover at least, and at best, plugged the passages in the cylinder head. The passages are sized perfectly for tapping for a 1/8" pipe plug. Keep this in mind in case the problem recurs.
Steve
---- shampson <shampson at gmx.co.uk> wrote:
> My blue Gpz has been off the road this past month due to one job leading to
> another to another.
>
>
>
> Initially I thought I had a major problem. Whilst on a day trip my brother
> in law told me I was smoking after a blast down a motorway but it seemed to
> clear up during the ride. A week later another blast down a motorway and the
> smoking reappears. A white cloud viewed through the rear view mirrors
> following me down the road. Though performance did not seem to be impaired
> at all.
>
>
>
> Well, my limited knowledge concluded only three ways for oil to get in the
> combustion chamber, bypassing the valve seals, oil ring bypass or a cracked
> head between the oil ways. I stripped the bike to find out. 1st tell tale
> sign was wet oil residue in the headers on cylinders 3 & 4. After removing
> the head I found wet residue on the exhaust ports and around the valve
> stems. Good news as valve oil seals are cheap.
>
> As the head was off I gave it a good clean up and stripped it down, reseated
> the valves, all inlet valves seem Ok and required minimal work, nearly all
> the exhaust valves required a few minutes on each. I decoked the combustion
> chambers which were’nt to bad as the motor only has 28500 miles on it.
>
>
>
> Like I said on job leads to another, so I checked the bores pistons and
> rings, all were well within tolerance when measured, in fact they showed
> very little wear at all.
>
> Paint on the cylinders was showing its age and flaking so I got hold of some
> pearl cosmic grey 400ml rattle can £34 ($62)not cheap and gave them a fresh
> coat after blasting them clean.
>
> All was reassembled using new base and head gaskets.
>
> When I came to check the valve clearance I thought they might be a bit out
> due to new gaskets but I completely forgot that reseating the valves will
> lessen the gap between the valve head and followers. Doh! I had to wait a
> few days for some new shims.
>
> I also bought a new head cover gasket on ebay for zrx1100, I thought they
> were the same but this one did’nt fit. The rear lefthand corner on the Gpz
> is angled 45 deg the zrx gasket was at 90 deg. So I reused the original
> with a splash of silicone sealant.
>
> When I came to connect the oil feed pipe to the cylinder head I noticed the
> thread on the casting that fits on the head left side was cross threaded. It
> came of easily after the initial loosening, so must have been done by a
> previous owner or at the factory. This was to cause me the biggest headache
> as the casting is £15 ($30) reasonable, but the pipe is £65
> ($130)extortionate. In the end I bought a full set plus the casting for £35
> on ebay Germany.
>
>
>
> Onto the next job, the gear change shaft oil seal. Only weeping very
> slightly but as I was ordering parts why not do it. I did it without
> removing the cover by using a bet screwdriver blade to hook and drag the
> seal out. Cleaned up the shaft and fitted the new seal.
>
>
>
> Next up was a new xring chain 17t front and 47t rear sprockets. All went
> well after I had worked out which way the countershaft nut comes off. On
> reassembly I thought I must have something wrong. The chain was 133 links
> and would need shortening to 112. Before hacking the chain I pushed the rear
> wheel all the way forward as far as it would go. When I linked the chain up
> it was only just in the 35mm to 45mm slack limit at 35mm. It seem a bit to
> close for my liking but at the other end which would require a further two
> links it would of had very little adjustment left.
>
> Anyone else encountered this when using a 47T rear sprocket?
>
>
>
> Onto head race bearings, top was dry and going rusty, bottom was well
> greased but on removal and cleaning, was found also to be going rusty. So
> both were replaced and liberally packed with grease.
>
>
>
> Dropping down the fork legs to the callipers, I thought I would just give
> them a clean out and fit some EBC pads I’ve had for a while now. However
> this turned out to be an expensive episode. A full refurb was required
> before I could fit new pads. The pistons were corroded on the top 5mm, which
> gets exposed to the elements when the pads wear down. A new set of pistons a
> seals were ordered £115 ($230) ooouch!. While the callipers were off I
> blasted the flaking paint off and used a two pack calliper paint for cars on
> them. The finish was awful, lumpy and streaky. So it was stripped of and
> replaced with a silver paint and clearcoat. Much better but may not be too
> resistant to brake fluid.
>
>
>
> All in all its took nearly 4 weeks to get done, including balancing the
> carbs and changing all fluids, oil, coolant, brake and clutch fluids and
> fork oil.
>
>
>
> 16 valve seals £28.20
>
> Head gasket £30.56
>
> Base Gasket £12.16
>
> Oil pipes
> £35.00
>
> Valve shims £8.00
>
> Gearshange shaft oil seal £2.33
>
> Caliper pistons, seals, rubbers, pins £114.69
>
> Caliper paint 1 £19.99
>
> Caliper paint 2 £14.00
>
> Front EBC HH pads full set £25.40
>
> X-ring chain and sprockets £69.50
>
> Cosmic grey paint & primer £33.93
>
> Engine oil
> £35.00
>
> Engine Coolant £15.00
>
> Total
> £443.76 ($887)
>
>
>
> Some of the parts and consumables I already had so it was that great a hit
> to the wallet but it was’nt cheap by any means.
>
>
>
> Here’s to a good few thousand miles free riding, with exception of oil,
> filters and tyres and ohh! Cheap fuel, yeah right.
>
>
>
>
>
> Cheers
>
> Steve
>
> Back riding the winter salt filled UK roads.
>
>
>
>
>
>
>
>
>
>
>
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