I am a non-mechanic who bought a 2001 garage queen GS500 with 1600 miles.  Tank needed de-rusting and carbs cleaned, but now it runs well.  But, the original owner never did the initial 600 mile valve check, and the bike is now 17 years old.  A mechanic who wanted $300 for a valve adjustment told me I should definitely have the valves checked, but another one told me that unless you are really stressing the engine with sporty riding they will go upward of 30,000 miles without being adjusted.  It is a shimmed design, which apparently has the advantage that that there is nothing to come loose and the valve clearance drift is due to the shim slowly wearing.  That supports the guy who told me 30k plus miles between adjustments, but the official check and adjust interval is only 4000 miles.  So, the question is, why such a short adjustment interval in a shimmed design?  Many other bikes have 8000 to 16,000 mile adjustment intervals.  Do the upper and lower spring seats on the valve stem drift?  Does the shim need to shift to take into account wear on the valve itself? 

Most mal-adjustment occurs when valveheads and valveseats wear, Sometimes the valvestems can stretch a bit too.
I personally wouldn't worry too much unless you can HEAR excess clearance. Take it to an experienced mechanic get him to listen to it,
if clearance is excessive he'll HEAR it.
4000 miles check? Naaah!

Thanks, Jools.  I did find a mechanic's posting on-line on the general subject that agrees with you.  It said "Most of the wear in the valve train occurs at the valve and seat, as the seat tends to recede and the valve pulls further into the head.  This wear happens most rapidly with a new engine and the valve clearances tend to close up relatively quickly. As the parts bed in, clearances tend to stabilize. That is why the first one or two valve adjustments are most important."

Well, that explains that it's not the shim but the valve head and seat that are wearing, and also explains why a lot of bike like the GS500 and the new Honda CB500 line call for a valve adjustment at 600 miles.  So, I guess I'll pay that $300 or figure out how to adjust it myself (up to now, changing oil and plugs has been my limit). 

But, it does not explain why the valve adjustment interval on the GS500 is 4000 miles, and the interval on the CB500 is 16,000 miles.  I know Honda has a little better reputation for quality, but their metallurgy cannot be 4 times better than Suzuki. 

{Disclaimer!  I'm neither an expert nor in training to be one, the following is just opinion/speculation.}

Quote from: MaxD on August 09, 2018, 06:50:03 PM
But, it does not explain why the valve adjustment interval on the GS500 is 4000 miles, and the interval on the CB500 is 16,000 miles.  I know Honda has a little better reputation for quality, but their metallurgy cannot be 4 times better than Suzuki.

It could very well be.  One thing to consider about the GS is it's designed to be rather inexpensive, as well as taking most of it's engine design from even older models.  I'm sure they cut cost in the castings and the R&D department.

So you're essentially looking at a 1970s bike and comparing it to a fairly recent 2000-teens bike.  Of course the Honda is going to be much better when it comes to those sort of things.  Hell, the Honda even uses a screw-on oil filter, is fuel injected, is liquid cooled, and has ABS, talk about high tech!

It's not just those bikes, either.  In a more or less apples to apples comparison my 2000 Ducati M750 has a 6000 mile valve interval.  My buddy just got a 2018 Hyper with the 939 engine and he claims it's a 14000 mile service.

As a theme one might think that "hey, the bikes with the longer intervals are all liquid cooled" and you might be on to something.  Seems to make sense to me that an engine with a more stable temperature management system would see more longevity from it's parts.

That being said, the KTM RC390 also has a 4000 mile valve inspection interval.  However, as with everything KTM being "Ready to Race" that seems to make sense to me.  It's part of the reason I decided against an RC as a "fun bike" for myself and am instead looking at the far less powerful (and not as cool) Ninja 300.  Kawasaki reliability and ease of maintenance wins in the end, if you ask me.

I agree with the above.

The model is coming up to 30 years old and the engine/box is based on 70s, maybe even 60s design and manufacturing technology and the whole bike was built down to a price. Compare it what was around in the mid/late 80s.

Modern.....It ain't!

Watcher, thanks for the input.  I also see here a couple of very detailed comments by "gsJack".  He has kept a log of valve recession vs setting clearance over nearly 200,000 miles of GS500 riding.  What he found that was staying in the middle of the spec range of 0.03 to 0.08mm allowed fairly high valve recession rates, especially the exhaust.  This is probably the source of the 4000 mile interval.  But, he has tried his just higher than the spec range, with exhaust vales set from 0.08 to 0.13mm, and with those wider settings the recession slowed WAY down.  The reason is that the valve spends less time open and more time closed where it is in contact with the head and can conduct its heat away.  The risk of the settings above spec is that revving to redline can possibly throw a shim.  So, I'm going to learn to set those and keep mine right at the upper limit of the spec--0.08mm. 

Looking round the internet I find that modern watercooled bike designers are generally going to a lot of trouble to keep the heads cooled, and in particular the exhaust valves.  I read an article on the new Harley "Milwaukee 8" (8 valves instead of 4) engine that went into detail about all the extra coolant flow they put in around the exhaust valves. 

A 1979 Honda CX500 was my first bike--I rode it all through college.  If I wear out this GS500, a CB500X is probably my next bike.   I'll have gone a lifetime with nothing but 500's--they just make good sense.  But, since you are interested in the Ninja 300, I might mention that I read a review on the new 2018 Ninja 400.  Supposedly just a terrific little bike.  About the same horsepower as the GS500, but liquid cooled and about 50 lbs lighter.  They'll probably come out with a Versys 400 with that engine if you want something more general. 

Quote from: Watcher on August 09, 2018, 09:45:19 PM
...
That being said, the KTM RC390 also has a 4000 mile valve inspection interval.  However, as with everything KTM being "Ready to Race" that seems to make sense to me.  It's part of the reason I decided against an RC as a "fun bike" for myself and am instead looking at the far less powerful (and not as cool) Ninja 300.  Kawasaki reliability and ease of maintenance wins in the end, if you ask me.

If you're just looking for a track-focused bike, a 4000 mile valve inspection interval isn't that bad. You'll just check the valves every few track days, right? Wouldn't that be like once a year at most? How many track days are you planning on doing per year?

Quote from: MaxD on August 10, 2018, 07:23:43 AM
Watcher, thanks for the input.  I also see here a couple of very detailed comments by "gsJack". 

Yeah I think Watcher and gsJack are right on about this stuff. I would speculate that the amount of time you spend at very high revs would have a similar effect on accelerating valve wear.

QuoteIf I wear out this GS500, a CB500X is probably my next bike.  ...  I might mention that I read a review on the new 2018 Ninja 400.  Supposedly just a terrific little bike.  About the same horsepower as the GS500, but liquid cooled and about 50 lbs lighter.  They'll probably come out with a Versys 400 with that engine if you want something more general.

Those CB500X look great, and the Ninja 400 looks pretty good too. Wish they would make a naked version. Versys 400 would be a really good option too. I do wonder what is the market driver for these bikes. It's just funny how you had Ninja 250, 500 and 650 twins, then the 500 went away, 250 went to 300, now 400, are they going to make it a 500 and introduce a "new" 250 then?

Not to get too far off topic, but yes, the Ninja 400 is awesome and more or less a no brainier.  I even test rode one and while the ride was disappointing the bike wasn't.

BUT, I have both poor credit and a desire to get a bike for cheap that I can thrash around and not feel bad about crashing on.  The longer the 400 is out the cheaper the 300s get and there's already tons of aftermarket support for them.
Re: RC track bike, for one I don't  have adequate work space and for two I don't own a car more or less a trailer.  I want a daily rider that I may take to the track.  That means I need more longevity and more ease of maintenance.

Watcher, I know what you mean about the value of used vehicles.  I picked up this like new GS500 with 1600 miles for $2000--about 36% of new cost.  Before that I got a like new Mazda Miata with 8000 miles for $7000 as my daily driver--again basically 1/3 of new cost.  Once you figure out that being patient and careful with used vehicle buys can get you those kinds of deals, you never want to spend the high price on new vehicles again.  Part of the pleasure of the GS500 is the pennies per mile it has been costing me--so long as I can find a good deal on those overpriced shims.  $16 each from the dealer for a $1 piece of cast steel is real rip off.     

Quote from: MaxD on August 10, 2018, 11:55:03 AM
$16 each from the dealer for a $1 piece of cast steel is real rip off.   

Well you're not really meant to buy a "set". Measure your current valve clearances and shims, do the math to determine what size shims you need if they can't be swapped around on your bike. Then buy one or two $16 shims to fit.

Back when I had a Miata, which also had the bucket-shim valvetrain on certain cars, we had sort of a virtual swap meet for shims where users on miata.net would trade shims or pass around a collection of shims. Come to think of it I have an egg carton full of >12 different size shims with >1 of each size in the garage now and I haven't had a Miata for nearly 3 years. I guess if this was such a big problem on GS500s we'd have the same kind of thing going on here. Of course on a Miata there are 4x as many shims so 4x as many you might have to buy. They don't really wear appreciably in normal use so used shims should be as good as new ones. Always wondered why I never see them in this forum's marketplace. I'm guessing it's because as often as we check the valve clearances, they don't commonly require "adjustment". My Miata went 150K without requiring it while my old 240Z with truly adjustable cam followers (jam nut/etc) required actual adjustment probably every 6K miles.

Mr. 72, appreciate the input.  The only thing wrong with measure and order is the bike will be down awhile, and maybe twice as long if the first size ordered is not perfect despite the calculation.  What I'm getting from the real pros on here is keep that exhaust clearance right at 0.06 to 0.10 mm to get max service life and not risk throwing a shim, so you have to get it to the nearest 0.05.  I know the K&L's have a bit of a bad rep on here, but there was only 1 reported actual failure I saw.  Since the local Suzuki dealership actually uses them, I'm thinking about ordering the $110 kit from Amazon, unless I get more feedback that there really is a high failure rate on those.  I ride the bike easy, being 60 years old and not wanting to take a fall.   

I've had my 96 Miata for 16 years now.  Like the GS500, it was an older garage queen with low miles and basically like new despite being 6 years old when I got it.  Between the Miata and the GS500, that's about all the sport an older guy like me needs.  I sort of feel like I'm getting 90% of the fun for 30% of the price, so I'm real happy with both. 

1600 miles?
It's barely run in!
I have a 24 year old one with 10500 on the clock and all the clearances are still wiithin spec.

I think you are worrying about an issue that doesn't exsist.

The head bolts should be retourqued on the shakedown service. If it doesn't happen it can lead to leaks around the cylinder base gasket.I would be more concerned about this than valve clearances.

Hey Sledge.  I got the bike at 1600 miles, but I now have 2600 on it.  I just got the shop manual and saw there was supposed to be an initial valve adjustment after the break-in of 600 miles, which the original owner never did.  I found some pretty authoritative reporting on-line that the first one or two valve adjustments are important, as there is a lot of wearing in on a new engine.  Plus, since gsJack did that very nice long term experiment where he actually tracked wear rates for more than 100k miles over a range of clearances, and found that being on the high end of the exhaust spec makes the wear rate much slower, I wanted to take advantage of what he found.  That could be done perfectly without risking throwing a shim if the shims came in small steps like 0.02mm.  Unfortunately these $1 pieces of cast steel cost $16 from Suzuki and must be special ordered, and only come in increments of 0.05mm.  My local Suzuki dealer reports they actually use the much cheaper and more available K&L shims, so I was thinking of getting the $110 K&L kit from Amazon.  Building up a similar kit of OEM shims would cost about $700 with tax.  There is at least one report of a K&L shim breaking here, but I don't know if that was a fluke or a trend. 

What would be great would be if we could get some on-line trading of the OEM shims here on GStwin.     

Sledge, thanks for the tip on the head bolts.  I'll make sure to torque them to spec shortly when I do this valve check. 

I'm with Sledge on this topic.  Don't let everyone overwhelm you with hairsplitting. I didn't touch my engine until about 8400 miles. I checked it myself and one valve was borderline. I put the cover back on and took it to the shop. I'm sure I could have gone many miles more without worry. I'm at 16k now and haven't even given it a second thought. IMO and my advice is to forget about it for several thousand more miles if everything is running good. If it really bothers you its easy enough to check the clearances yourself and put the valve cover back on without special tools. If they are out of spec take it to a shop and let them do  the actual shim swap.

I got my money's worth of fun out of my GS so I'm not going to stress out about the engine until/ if I have noticeable performance issues. There are more important maintenance items to worry about spending money on. Tires, brakes, chain slack, OIL! Not to mention upgrading the suspension.

My Honda VFR has a 16k valve check interval. I'm at 32k and haven't touched it. The bike is 18 years old and runs like a top.

I forgot when my lawn mower was due for a check. I'm sure its waaaaaaay past due. Valves are so loud I wear ear plugs.

Hello Pliskin:  OK, thanks.  I already ordered the special tool to depress the bucket, and a magnetic wand to pull out the shim, and a nice feeler gauge, from Amazon for about $8 each.  There are excellent videos on YouTube showing the procedure.  So, when I check it I'll probably go ahead and swap the shim myself while I have it open.  It will be my first time doing it, but in the city I live we have a well known and well regarded motorcycle mechanic who comes out and works at your house for a rate of $80 per hour.  So, if I get in trouble, I can get him here to show me where I'm going wrong.  It seems easy enough that I can probably get it right the first time, but if not I'll have this guy teach me. 

like pilskin I think you're making way too big of a deal out of this. There is a bit of a cult here on gstwins whose members pop up occasionally when someone is having one of a class of issues to suggest it is "tight valves" but I have yet to see a time when this was the sole issue or could even have been logically be found as the root cause of whatever the problem is.

Running the valve clearances too low will potentially lead to much worse problems so it's worth it to keep an eye on it but it doesn't change quickly and having >0 clearance is really the goal, and having the clearances suddenly become larger can be an indication of other serious problems so again it's worthwhile to check/measure but that doesn't mean you are going to have to frequently remedy it. I think of it like my Jeep that's only a few years old... running it out of oil would be a disaster and if the oil level went up it would also indicate a serious problem so checking the oil regularly allows me to monitor these other potential issues, but truthfully I don't expect to ever have to adjust the oil level.

Valve checking is pretty straightforward, all you need is $3 feeler gauges. Especially easy if you have an older bike without all the vacuum line spaghetti.

Feelers?.......nah.

Get a roll of shim stock. Far more accurate than cheap feelers gauges and you can trim it to a convenient size.

http://www.repco-tech.co.uk/shims-product?shim_id=13

At one time this forum had a valve adjustment kit in circulation between members. A selection of shims, feelers, a micrometer, a releasing tool etc. Everything you needed.

Dunno what happened to it