Valve check - ended badly.

[potter0o]

If the manual says to replace the parts I have them on hand. I have not had to use any of them except the crush washer for the oil change. So far seems to be an insurance policy against failure. I commute with the bike so I would not be happy if it were down waiting for a part to come in.

 

[josh4tennis]

An update:

Finally the bolt I ordered arrived this week, and I managed to leave work early and pick it up today. I replaced the bolt and put everything back together... and wow, she sounds really different. I'm not sure if it's because I haven't heard the engine in a while, but I'm beginning to think that I've done something incorrectly. The sound from near the valves sounds a lot more "airy" almost like the sound of the air being sucked through an air filter. She also struggled to start, but I think that could be down to the fact that I hadn't been able to run the engine for three weeks. However, she's idling perfectly and I would say the engine feels more free in its ability to rev. Now, I'm not sure that simply loosening the exhaust valve on one cylinder would cause this much difference in sound and feel. Am I wrong? Or is this simply my mind playing tricks on me?

Sent from my SM-N910F using Tapatalk

 

[670cc]

Any minor change to the valve train would be undetectable to me. Temperature, barometric pressure, my attitude, and probably the wind would make more difference than tweaking a valve a little.

By the way, loosening the clearance of an exhaust valve means the valve now does not open as far, hence if anything the engine breathes less freely. If you thought because you loosened it, that is is now breathing more freely, then that truly is in your mind, because it's the opposite of reality.

Anyway, I'm glad your NC is back in service.

 

[lootzyan]

...loosening the clearance of an exhaust valve means the valve now does not open as far, hence if anything the engine breathes less freely...

Just to avoid confusion, changing valve clearance doesn't regulate how far valve is open but for how long valve is open.

 

[670cc]

Just to avoid confusion, changing valve clearance doesn't regulate how far valve is open but for how long valve is open.

It affects both lift and duration.

To demonstrate, if one one was to turn the cam lobe to its peak to open the valve, adjusting the rocker arm screw would then raise or lower the valve, would it not?

Loosening the screw will delay the opening, lessen the lift, and quicken the closing.

 

[lootzyan]

Theoretically yes, but amount of lift change is insignificant.
Let's say clearance was changed by 1/2 of specs range. This could make valve timing change by couple of degrees but valve lift would change by about 0.02 mm (0.001"). I don't know what is total amount of valve opening - 5-7 mm ?

 

[670cc]

So contrary to your earlier statement in post #24, adjusting the screw DOES regulate lift.

 

[lootzyan]

So contrary to your earlier statement in post #24, adjusting the screw DOES regulate lift.

Yes, but again, change in valve opening is so small it is dismissed and doesn't play any role in engine performance, if is in specs.
For example, allowed by Honda deviation in cam lobe height, which effects valve lift, is 10 times bigger that valve clearance range.

 

[670cc]

Yes, but again, change in valve opening is so small it is dismissed and doesn't play any role in engine performance, if is in specs.
For example, allowed by Honda deviation in cam lobe height, which effects valve lift, is 10 times bigger that valve clearance range.

I'll take that as a yes.

 

[showkey]

If you want to prove this point of lift and duration and overlap changing with valve clearance ..........monitor MAP value ( manifold pressure, aka vacuum) while at idle. Then change the valve adjustment..........You will see MAP changes significantly with valve clearance settings.

There are times when auto engines valves ( manual tappets) are set to the tight side of the spec to resolve random misfire codes on overly sensitive OBD systems.

 

[Grey1one]

you mean when they are correct ?

 

[rippin209]

"I'm very interested in how you make out as I will be doing my valves in a few thousand km's and didn't even know where the valve cover was until I saw this picture! I don't know what it means for valves to be 'tight', but I want to learn, so will do it myself. It's all part of the sport".

I'm sure that I am a minority on this site being that I totally disagree with the above statement : It's all part of the sport. I totally enjoy the sport of motorcycle riding without having to tear apart an engine to see what makes it tick or make it tick better, change the suspension around to make it a little firmer or softer, change tires when needed and so on. Yes, I do believe one should have the skills to check the fluids, lights, horn and other safety items. Does this mean I have been missing a big portion of my sport ?? I am much happier leaving this part of the sport, as you call it, to others that enjoy, are trained, paid and knowledgeable enough to do so. Let them spend their Saturday playing in oil, grease, gas and scraping their knuckles while cussing at a broken bolt. Time is the most precious item humans have and I thinking that saving a few dollars here and there, at times is not worth it. However to those that enjoy this part of the sport - go for it and have fun. Just my opinion.

I here what your saying and partly agree. For me currently it's mostly the money saving, motorcycle techs are expensive where I live (as most places) I have the ability to work on my cars trucks and motorcycles but don't necessarily enjoy it (I definitely wouldn't do it as a job) and I have friends and family that have had professional shops screw up their vehicle and if it is made right it's still a pain, but if I had the money and a mechanic that I trusted I would have someone else working on my vehicles. The fact that time is precious is highly under rated. I spend about 10 hours a week commuting and have done so on my motorcycle for two years for the last three weeks I've driven my car do to extreme weather and my motorcycle being down for repair and the parts being on back order, I'm back on two wheels and really appreciating it again. Small change but a big difference. I hope you all make the most of every day, stay safe out there

 

[Techrat]

I'm a newbie to maintenance myself. After the maintenance and a couple of hundred miles, I want to know how josh4tennis bike rides. Is it better, worse or the same? Sounding different and feeling different are two different things.

 

[showkey]

I'm a newbie to maintenance myself. After the maintenance and a couple of hundred miles, I want to know how josh4tennis bike rides. Is it better, worse or the same? Sounding different and feeling different are two different things.

See post #23 pretty much covers it...............the placebo effect is the best answer.

 

[serge]

"I'm very interested in how you make out as I will be doing my valves in a few thousand km's and didn't even know where the valve cover was until I saw this picture! I don't know what it means for valves to be 'tight', but I want to learn, so will do it myself. It's all part of the sport".

I'm sure that I am a minority on this site being that I totally disagree with the above statement : It's all part of the sport. I totally enjoy the sport of motorcycle riding without having to tear apart an engine to see what makes it tick or make it tick better, change the suspension around to make it a little firmer or softer, change tires when needed and so on. Yes, I do believe one should have the skills to check the fluids, lights, horn and other safety items. Does this mean I have been missing a big portion of my sport ?? I am much happier leaving this part of the sport, as you call it, to others that enjoy, are trained, paid and knowledgeable enough to do so. Let them spend their Saturday playing in oil, grease, gas and scraping their knuckles while cussing at a broken bolt. Time is the most precious item humans have and I thinking that saving a few dollars here and there, at times is not worth it. However to those that enjoy this part of the sport - go for it and have fun. Just my opinion.

That depends on the sport. If you are riding in the boonies by yourself, knowing a little how your machine works can save you from a long walk... and there are a lot of boonies in RSA