Valve Adjustment intervals and reliability?

[TwistedKestrel]

Honda is good.My Goldwing 1800 has 100k and the solid lifters are still in spec.

Probably because if it was any more frequent on a Wing, nobody would do it

 

[Motorcycle Mike]

Bear in mind that different valve types will have different service intervals (or none at all)... but some valve types are also easier to adjust than others: http://www.dansmc.com/valveclearence.htm

For example...

The DRZ 400 has a 24000km inspection interval and uses shim type valve adjustment... meaning it is a more involved process to actually adjust the valves if they are out of spec. A road side adjustment is out of the question unless you carry a bunch of different sized shims with you...

The DR650, on the other hand, has only a 12000km inspection interval, but has screw adjustable valves meaning a valve adjustment can be done in 30 minutes (and trail side, if need be) once you know what you are doing.

On a bike like the dr650, I don't mind short inspection and adjustment intervals because it is a simple bike. Easy to remove the tank, no rad, etc, easy to access the valves. The DRZ is also easy to access. My Vstrom has a 24000 check interval, and I wish it was longer because it's a PITA to access the valves...

Personally, because I try to do all work myself, I like to keep it simple. When it's time to give up my Vstrom and DRZ I will likely go to a DR650.

 

[Brian P]

Or just get a VFR and don't worry about having to do the valve check till close to 100k

But heaven help when that day comes, if it is a VTEC model. (and I thought the inspection interval was 50k on those but I could be wrong)

4 camshafts in 2 banks with 2 tensioners and they all have to come out to install VTEC locking tools then reinstalled to check clearances, then out again to remove the locking tools and to change any necessary shims, then in again. It is a big job.

I suspect a lot of them never get checked ... and probably never need it.

Many car engines have shim-type adjustment and never get checked and never need it. Many Toyota and Mitsubishi engines are like this and there are probably others.

 

[boyoboy]

valves too tight most notably cause lack of heat transfer from head of valve to the seat in the head, not only does the valve face surface deform easier in this overheated condition but the oil on the stem burns and causes problems in the guide such as sticking valves (common in large twins that get pipes and no jetting).
Valve seating pressure also keeps the seat and face clean, if valve is tight this pressure is lessened, allowing the beginnings of cascading issues I mentioned.

Too loose will at least be allowing oil between parts and the valve can shed it's heat to its seat, eventually it can lead to other wear problems. On many valve trains with rocker arms it's not necessarily bad to hear some ticking.

Maintaining your engine according to manufacturers specifications is good for most owners but be aware that maintenance intervals must be adjusted if an engine is seeing heavier or more severe use. In other words, if an engine is living a harder life it should see more maintenance. I advise this to dealers filing warranty claims for the same repeated repair.

a valve that is too tight will not completely close, this allows hot combustion gases to escape past the valve / seat. These hot gases passing by are the source of heat that burns the valve. This condition is compounded by the lack of heat transfer you mentioned.

 

[yodude]

HD has had hydraulic lifters for years, they apparently have a self adjusting lifter system now that works with engine expansion from heat and wear and has zero lash on the valve train.

An almost completely maintenence free system won't stop guys from replacing the hydraulics with solid lifters to gain a 1/4hp...... that and loud valves save lives.

beanies are for the birds too

 

[Roadghost]

This is bad advise. Sorry to say.
In a modern bike , if you at a point where you hear clanking - it is too late. Now you are replacing components.

But every bike I have owned doesn't agree with you. You hear tapping before the required maintenance interval you adjust. If you keep hearing it you look further. I have never had to replace parts for loose tappets. All my jap bikes have had a recommended shop manual tolerance of around .005, so bond paper at .006 works just fine. Not sure what "new" bike you're talking about, I'm sure I can't speak for all of them, but this has been my experience and I have never gone wrong.

At 24K-25K if the factory manual says it needs a adjustment - 9/10 - it will need it adjusted.
Modern bikes with tight clearances and multiple valves per cylinder are sensitive to valve clearances.
Add throttle / fly by wire , electronic controlled servo motors throttle bodies - it gets even more important.

What specific bikes are you talking about? What are the tolerances required for say, an H2 or a GPZ? .005 is pretty tight, but I'm guessing liquid cooled allows for less? I think there are slight differences between the intake and exhaust on newer bikes, for example with a Ninja:

~Exhaust 0.22 ∼ 0.31 mm (0.0087 ∼ 0.0122 in.)
Intake 0.15 ∼ 0.24 mm (0.0059 ∼ 0.0094 in.)

Again, you want to refer to the manual.

Too tight = wear cams, galls cams , valves seals
too loose = gets expensive, big loss of power.

Bond paper for a feeler gauge = bad idea.

But if you're doing it right you shouldn't have any problems. That means following the manual, having the lobes in correct position and if it's .005 (usually on older bikes) then .006 bond paper is an old trick and it works just fine. You can even adjust the valves by ear if you want. But you also want to be in spec, and on prissy-***** Italian spaghetti-burners you might want to invest in the tools. For the rest of us mortals it's the backyard method.

 

[Roadghost]

A bit off topic.Harley has a new motor with zero maintenance valve train.This'll be fun to watch.

Harley's valve trains have been maintenance free with hydraulic lifters for a long time. I know the HD mechanics are doing the big build-up on the new Milwaukee-8, but the stuff about the valve train is just salesmanship. They don't have the same problems the OHC engines do.

 

[Neil_V]

Harley's valve trains have been maintenance free with hydraulic lifters for a long time. I know the HD mechanics are doing the big build-up on the new Milwaukee-8, but the stuff about the valve train is just salesmanship. They don't have the same problems the OHC engines do.

You mean the same problems those built to rev over 7k do. The main problem being valve float, which is why hydraulic lifters are not used in say, a CBR 1k.

 

[TwistedKestrel]

But if you're doing it right you shouldn't have any problems. That means following the manual, having the lobes in correct position and if it's .005 (usually on older bikes) then .006 bond paper is an old trick and it works just fine. You can even adjust the valves by ear if you want. But you also want to be in spec, and on prissy-***** Italian spaghetti-burners you might want to invest in the tools. For the rest of us mortals it's the backyard method.

Keeping in mind that a set of feeler gauges would be $10-20, something that even mortals could afford. And they can measure more than one size of gap. Do you mic your bond paper when you use it?

 

[boyoboy]

Keeping in mind that a set of feeler gauges would be $10-20, something that even mortals could afford. And they can measure more than one size of gap. Do you mic your bond paper when you use it?

this^ by ear is a joke i think? how do you hear a tight valve? frekey guy is correct.

feeler gauges will also measure out of spec clearances so you can do the math and choose the right shim - and are a must have to do your clearances properly
I measure the shims with a mic. as occasionally the stamped number on the shim is not accurate by a small amount

 

[Roadghost]

You mean the same problems those built to rev over 7k do. The main problem being valve float, which is why hydraulic lifters are not used in say, a CBR 1k.

LOL. Are we going to talk about valve adjustments, or the merits of pushrod vs OHC engines? Not sure I want to take the bait.

 

[Roadghost]

Keeping in mind that a set of feeler gauges would be $10-20, something that even mortals could afford. And they can measure more than one size of gap. Do you mic your bond paper when you use it?

You can use a set of Vernier calipers. To be clear I'm talking about an SOHC engine, NOT a DOHC engine that requires shims. BTW, what's with the goofs who are worried about tightening the lash too much? If you do that you aren't following any manual, and you probably shouldn't be working on an engine, ever. This isn't rocket science:

https://www.youtube.com/watch?v=-sdNdcbQ77k

 

[Roadghost]

this^ by ear is a joke i think? how do you hear a tight valve? frekey guy is correct.

On OHV engines the old school method was to run the engine until warm then adjust the lash by ear. You cannot do that with newer DOHC engines, nor can you simply use bond paper to test for clearance. I believe that's what frekey guy was alluding to. You also need to shim for lash on newer engines, rather than simply adjusting the rockers with a screw driver and 10mm wrench, which you can do with SOHC engines. So, to be clear he is talking about the newer more annoyingly complex designs that generally don't get fixed and end up at the wrecker.

I'm talking about SOHC engines, popular in the older, cheaper and less ridiculously complex models.

feeler gauges will also measure out of spec clearances so you can do the math and choose the right shim - and are a must have to do your clearances properly
I measure the shims with a mic. as occasionally the stamped number on the shim is not accurate by a small amount

How far out have you found your clearances after the recommended service interval?

 

[Roadghost]

About to get my honda's valves adjusted(because the previous owners never did) its right around the 25k mark which is when they should get adjusted/checked anyway.

I was looking at yamaha's website and noticed they have valve adjustment intervals at every 42k.

Is this a way to gauge a bikes/engines reliability? The longer it can go without valves adjusted, the better?

Is this another one of those indicators , like the lower rpm redlines, that are a good indicator of a reliable/bulletproof bike(or engine?)

To answer your question directly, a Harley Davidson never requires having its valves adjusted. Never. I'm guessing that's one of the reasons they call it the world's greatest motorcycle. So the answer is YES, the longer it can go without a valve adjustment, the better.

 

[yodude]

About to get my honda's valves adjusted(because the previous owners never did) its right around the 25k mark which is when they should get adjusted/checked anyway.

just do it, get it done ..or whatever

I was looking at yamaha's website and noticed they have valve adjustment intervals at every 42k.

Is this a way to gauge a bikes/engines reliability? The longer it can go without valves adjusted, the better?

Is this another one of those indicators , like the lower rpm redlines, that are a good indicator of a reliable/bulletproof bike(or engine?)

 

[boyoboy]

ive found valve shim clearance off so much that the cyl pressure was down ~ 60psi (tight valve). if it had been left like this the valve would have burned.
why do you ask?

 

[yodude]

You can use a set of Vernier calipers. To be clear I'm talking about an SOHC engine, NOT a DOHC engine that requires shims. BTW, what's with the goofs who are worried about tightening the lash too much? If you do that you aren't following any manual, and you probably shouldn't be working on an engine, ever. This isn't rocket science:

https://www.youtube.com/watch?v=-sdNdcbQ77k

suzuki started with shims on their first & new dohc 8 valve fours, then went tappet adjust on their next dohc 16 valve stuff,

honda went hydro on 1200 - 1500 wing stuff, tho solid for Valkyrie & also 1800

 

[bocutter]

so bond paper at .006 works just fine.

Have you ever put a micrometer on your 'bond' paper? Standard office 20lb bond/50lb offset is nowhere near .006" (45+ years experience with the stuff).

 

[yodude]

delete

 

[Neil_V]

Have you ever put a micrometer on your 'bond' paper? Standard office 20lb bond/50lb offset is nowhere near .006" (45+ years experience with the stuff).

Patiently waiting for Roadghost to tell you he knows better lol