Buying used and servicing

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The Spin Doctor
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Re: Buying used and servicing

Post by The Spin Doctor »

Le_Fromage_Grande wrote: Sun Jun 05, 2022 10:48 am
Mr. Dazzle wrote: Sun Jun 05, 2022 10:34 am Imagine doing that for a 16v engine!

Possible, but there's gotta be a more efficient way.
I suspect it's why Suzuki went screw and lock nut when they went to 16 valve engines, much quicker to set up on a production line than bucket and shims. Yamaha must have been confident of their quality control when they went shim under bucket on the 20 valve FZ750.
Lighter valves, less lift?

My 92 GSX-R ate its exhaust valves in double-quick time and ran out of adjustment in 30k miles... the engineer who eventually took the job on (the dealer wouldn't touch it - "we only do servicing") said that there was a period of a few years when Suzuki and Kawasaki suffered problems with a batch of 'soft' valves which were sourced from the same supplier. The replacements in the stock list came from a different supplier and were supposed to last a lot longer. I never found how how much longer because it ended up parked up for a few years before I sold it, having got a bit fed up with it.
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Le_Fromage_Grande
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Re: Buying used and servicing

Post by Le_Fromage_Grande »

92 was the water cooled WN wasn't it, with bucket and shims?
I had an 85, an 88 and a 91 (and a 96 and a 2002, but they're completely different engines) the 85 and 88 were screw and lock nut and the clearances used to widen up between services (3000 miles), the 91 was bucket and shim and the clearances never changed.
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Skub
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Re: Buying used and servicing

Post by Skub »

The Spin Doctor wrote: Sun Jun 05, 2022 12:01 pm My 92 GSX-R ate its exhaust valves in double-quick time and ran out of adjustment in 30k miles... the engineer who eventually took the job on (the dealer wouldn't touch it - "we only do servicing") said that there was a period of a few years when Suzuki and Kawasaki suffered problems with a batch of 'soft' valves which were sourced from the same supplier. The replacements in the stock list came from a different supplier and were supposed to last a lot longer. I never found how how much longer because it ended up parked up for a few years before I sold it, having got a bit fed up with it.
That happened me with my 84 GPZ900R. The valve clearance kept going tight (hard to start) until there was no clearance. It was a recognised fault,as you say and after having one of their techs examine the head,Kawasaki stumped up the cost of a set of valves and I did the job myself. The GPZ was fairly easy to work on.

Apart from reinstalling the airbox,don't get me started on that one. :(
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Mr. Dazzle
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Re: Buying used and servicing

Post by Mr. Dazzle »

That sort of thing happens all the time. Not valves specifically. You get a part which for all intents and purposes should work, meets all the specs etc. but then just....doesn't. Its cause there's some aspect of the design you didn't identify as being important. That's one of the big reasons you tend to see manufacturers sticking with certain ideas/trends over years and decades: they know what's important and what isn't when you're making it, often through painfully won knowledge.
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Re: Buying used and servicing

Post by Asian Boss »

IMO engines can be fine at high miles. Chassis parts less so, all the bushes will probably be worn and the suspension past its best; and as a result it'll ride like a pig fucking. Brakes often suffer at higher mileages too.
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Re: Buying used and servicing

Post by Le_Fromage_Grande »

Asian Boss wrote: Sun Jun 05, 2022 4:30 pm IMO engines can be fine at high miles. Chassis parts less so, all the bushes will probably be worn and the suspension past its best; and as a result it'll ride like a pig fucking. Brakes often suffer at higher mileages too.
This is very true, while the engine on my 65,000 mile FZ750 is fine, the cycle parts are getting tired, it could do with new bearings throughout, and an owner that could be arsed to do the work.
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