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Why check the valve clearance so frequently ?

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I'm not looking to start a debate but I am curious what is the need to check them as frequently as some suggest . If I understand correctly , the only harm is that the valve could possibly be wearing at the seat thereby causing less clearance between the shim buckets and the cam....causing poor starting /lack of power ??. I believe that I read that if the valve clearance does in fact change that dramatically then you are likely due for new seats/valves anyhow. So , what is the benefit of checking them so often ?

Please note , I am not agreeing or disagreeing with anyones opinions......I am simply trying to understand . :thumbsup:

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Not all of us agree.

Depends on use/abuse.

Much like the oil changing debate.

Suzuki reckons inspection every 24000km for my SM, and the way I treat it, that is probably OK - but I'll probably halve that anyway.

Cheers

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If you actually run with too little clearance you will damage the valves and seats.

If on the other hand you keep a regular check, you will be able to adjust the clearance and prevent any damage.

This won't prevent normal wear, but will stop any unnecessary damage.

It's up to you really, if you don't check them, and the clearance closes up, the first

you will know about it is the hard starting, and by then it will be too late.

A check costs nothing but time, new valves and seats is going to be $500 at least.

If money is not a problem, don't bother checking :ride:

Oh, and when it lets you down, it will be at the most inopportune moment, like 500 miles from home. :ride:

Neil. :thumbsup::cry::ride:

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Because they do move, and not on a schedule written by a lawyer working for Suzuki, advising technical manual writer, who has never held a wrench in his hand or ridden a motorcycle. If you check them, you will have a base line to know when they start to move,, and,, A know AHEAD of time when replacement is going to be needed, B not end upon a trail miles from no place and a bike that will not start, C do what you want it's your bike .... There is a D, E,F, G and more reasons why.. But,, those that understand why it is a smart maintenance practice will continue to think so, and those who do not, will continue to think it a waste of time,, No matter what is typed on some INTERNET site... So.. Go ride :thumbsup:

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Valve clearances gone bad can actually lead to valve/valve seat damage. That is why some people worry enough to check more frequently. I'm not taking a position on how often to check, but I would point out that if the clearances are changing fast enough to detect between the manufacturers suggested check intervals, you've got something serious going on in your valvetrain, and although that's good to know, it's still going to cost a fair amount to fix it - maybe as much as if you had not found the problem until after the clearances got too small.

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Valve clearances gone bad can actually lead to valve/valve seat damage. That is why some people worry enough to check more frequently. I'm not taking a position on how often to check, but I would point out that if the clearances are changing fast enough to detect between the manufacturers suggested check intervals, you've got something serious going on in your valvetrain, and although that's good to know, it's still going to cost a fair amount to fix it - maybe as much as if you had not found the problem until after the clearances got too small.
You were on a roll for a few,, then came the last part.

Do a few searches, read the empirical data, look up the prices of replacement parts,,, Then tell us again how a trashed motor caused by failed valve train is the same cost to repair as installing new valves when you notice them starting to recede into the head. :thumbsup:

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Well, I still think it is overkill - a quality piece of machinery should be able to be relied upon to stay in spec within reasonable timeframes with reasonable use.

That said, there is some good advice here from people who know their stuff - especially the bit about it being an easy preventitive.

I don't think mine knows what 10 000rpm is....

Cheers

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You were on a roll for a few,, then came the last part.

Do a few searches, read the empirical data, look up the prices of replacement parts,,, Then tell us again how a trashed motor caused by failed valve train is the same cost to repair as installing new valves when you notice them starting to recede into the head. :thumbsup:

That seems a little extreme - I didn't say that a new motor cost the same as a refurbished cylinder head!

There are two possible causes and three possible outcomes of unchecked valve clearance decrease:

1a) By far the most common - clearances decrease due to valve seat wear or recession, eventually resulting in 1 or more burned valves and seats. This process is slow, which explains the long manufacturer recommended check intervals.

1b) If the engine or valvetrain has been modified by someone that hasn't properly clearanced the engine, you can have piston to valve contact when the clearance gets too small - this will never happen on a stock engine, and any reputable engine builder will ensure that adequate valve to piston clearance exists to prevent contact at 0 valve clearance. One exception might be a racing application, but in this case the clearances should be checked before and after every race.

2) the decreasing clearance could be a sign that the valve is stretching, prior to a catastrophic failure. This could be the result of an extremely high mileage engine, or a poorly manufactured valve. This is the scenario that will trash the engine! In general, this type of failure is rare on stock 4 stroke engines. Is this bike an exception?

Have there been a large number of stock valve failures for this bike? I know that some have had issues with aftermarket valves, but hadn't seen any recent threads indicating that stock valves are a problem.

In the most common scenario, where the valve seat is wearing or receding - if you catch it at an inspection and decide it is progressing more rapidly than you are comfortable with, you are looking at replacement seats (not sure of a cost here, maybe $150 installed?) possibly new valves ($100 for stock parts), plus labor for teardown and reassembly.

If you let it continue until you burn a valve, you will need to either replace or resurface the seats and reface or replace the valves - at about the same cost as above.

In either case, if the seats are unreplaceable, a new head will set you back about $500

Again, I'm not making any recommendation about how often you should check, but I've seen posts from several here who say that they have never had to adjust the valves on this bike, which makes me feel good about the stock design. I'm sure Eddie could tell us whether he has seen a lot of low mileage valve adjustments in his experience.

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Well, I still think it is overkill - a quality piece of machinery should be able to be relied upon to stay in spec within reasonable timeframes with reasonable use.

That said, there is some good advice here from people who know their stuff - especially the bit about it being an easy preventitive.

I don't think mine knows what 10 000rpm is....

Cheers

Mine definately knows where 10,500 rpm is :thumbsup:

Have there been a large number of stock valve failures for this bike? I know that some have had issues with aftermarket valves, but hadn't seen any recent threads indicating that stock valves are a problem.

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And I can think of a couple of more guys who have had their stock two piece valves decide to become two pieces again. It has been well documented here. Not sure what you consider a "large number" but if it happened to you I bet you'd think twice about your valves.

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If you actually run with too little clearance you will damage the valves and seats.

Can you clarify ...How does too little clearance damage the valves/seats? Are you talking about enough damage to break a valve and cause catastrophic damage or simply erode the valves/seats.

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I'm sure Eddie could tell us whether he has seen a lot of low mileage valve adjustments in his experience.
He already has :thumbsup:

Like I said, do some searching .. This has been covered many times... I'm not guessing, theorizing, or making recommendations on what I heard or read. It's your bike... Maintain it as you wish.. I have no hard feelings one way or the other ... Now lets go ride.. I did today.. :ride:

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These are as good as oil threads. My feeling is that if you are sufficiently worried your valves will revert to base metal, replace them. The valve failure mode is the most common one after you fix the others. But it is not like they drop like flies at low mileage.

If you ride it like a race bike good for you. You shoulda bought an RMZ and then you would have had more power in the first place. The maintenance intervals would be bang on.

If I followed the intervals recommended by some my bike would be in pieces more than once a week. I would spend my precious little spare time wrenching. That is not why I bought a DRZ.

Mine sees the rev limiter regularily and will soon see 500 more rpm. That all said I have a spare engine sitting in the garage. I said I believe in the scheduled maintenance recommended by the ENGINEERS not LAWYERS doesn't mean I'm STUPID!

Now for a ride. :thumbsup:

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do a little math.

how many times per second does the valve open and close at 10,000 rpm.

166.66666.... per second!!!

WOW, that's fast.

Think I might just check my valve clearance again....

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bottom line,once they start moving they dont stop and recession happens very quickly.

once the wear is thru the coating the valve may last 1000 miles or 100 miles.

checking the valves is extremely easy.checking often may save a big planned trip.

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Originally Posted by Neil Claydon

If you actually run with too little clearance you will damage the valves and seats.

Can you clarify ...How does too little clearance damage the valves/seats? Are you talking about enough damage to break a valve and cause catastrophic damage or simply erode the valves/seats.

If you leave them to the point that there is no clearance, the valve is not shutting fully.

When that happens you will burn the valve and seat.

Neil.

:thumbsup::ride::cry:

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