Four valves at low end of clearance spec. Button her up or adjust?

[Fred W]

FIRST CHECK: 9/14/07 @28920 miles																			

left to right	Cylinder #1			Cylinder #2        			Cylinder #3        			Cylinder #4		
left exhaust	right exhaust		left exhaust	right exhaust		left exhaust	right exhaust		left exhaust	right exhaust	
0.229     		0.203        		0.229 		0.229        		0.203   	0.203        		0.229   	0.203	
left intake	right intake		left intake	right intake		left intake	right intake		left intake	right intake	
0.178        	0.178        		0.178   	0.178        		0.178        	0.178        		0.178        	0.152	


SECOND CHECK: 6/9/11 @54154 miles					             				
left to right	Cylinder #1			Cylinder #2        			Cylinder #3        			Cylinder #4		
left exhaust	right exhaust		left exhaust	right exhaust		left exhaust	right exhaust		left exhaust	right exhaust	
0.203        	0.203        		0.203        	0.203        		0.203        	0.203        		0.229    	0.178	
left intake	right intake		left intake	right intake		left intake	right intake		left intake	right intake	
0.178   	0.178        		0.178        	0.178        		0.178        	0.152T        		0.178    	0.152

Based on the above measurements I can see that you are actually measuring the clearances using inch based feeler gauges and then converting that to millimeters. The problems is that the gauges are too course to accurately know what your clearance really is at any one time. Example: .006" = .152mm, and .007" = .178mm. IOW, every increment of .001" in the inch based feelers is equivalent to .026 mm. Since the total spec range is .070 mm there are only 3 gauges to cover that range. You really do not know where within that .026mm the actual clearance is or was, therefore do noit really know how quickly the parts are wearing.

I prefer to consider the inch based gauges as "Go / No Go" gauges. If you can fit an .006" (.152mm) into the intakes or a .007" (.178mm) into the exhausts then the clearances are within specs and should be left the hell alone.

The good news is that in no case did you change by more than .001", so worst case should be that a few valves would be out by .001" or less at the next valve check.

BTW, the idea that you should just set them loose and then don't bother to check them for a longer time doesn't make a whole lot of sense to me, especially if you are doing the job yourself. The reason that you set them on the loose side is so you don't have to adjust them too soon. I'd still check them at the same intervals, as that helps with determination of wear rate.

 

[dannymax]

FIRST CHECK: 9/14/07 @28920 miles																			

left to right	Cylinder #1			Cylinder #2        			Cylinder #3        			Cylinder #4		
left exhaust	right exhaust		left exhaust	right exhaust		left exhaust	right exhaust		left exhaust	right exhaust	
0.229     		0.203        		0.229 		0.229        		0.203   	0.203        		0.229   	0.203	
left intake	right intake		left intake	right intake		left intake	right intake		left intake	right intake	
0.178        	0.178        		0.178   	0.178        		0.178        	0.178        		0.178        	0.152	


SECOND CHECK: 6/9/11 @54154 miles					             				
left to right	Cylinder #1			Cylinder #2        			Cylinder #3        			Cylinder #4		
left exhaust	right exhaust		left exhaust	right exhaust		left exhaust	right exhaust		left exhaust	right exhaust	
0.203        	0.203        		0.203        	0.203        		0.203        	0.203        		0.229    	0.178	
left intake	right intake		left intake	right intake		left intake	right intake		left intake	right intake	
0.178   	0.178        		0.178        	0.178        		0.178        	0.152T        		0.178    	0.152

Based on the above measurements I can see that you are actually measuring the clearances using inch based feeler gauges and then converting that to millimeters. The problems is that the gauges are too course to accurately know what your clearance really is at any one time. Example: .006" = .152mm, and .007" = .178mm. IOW, every increment of .001" in the inch based feelers is equivalent to .026 mm. Since the total spec range is .070 mm there are only 3 gauges to cover that range. You really do not know where within that .026mm the actual clearance is or was, therefore do noit really know how quickly the parts are wearing.

I prefer to consider the inch based gauges as "Go / No Go" gauges. If you can fit an .006" (.152mm) into the intakes or a .007" (.178mm) into the exhausts then the clearances are within specs and should be left the hell alone.

The good news is that in no case did you change by more than .001", so worst case should be that a few valves would be out by .001" or less at the next valve check.

BTW, the idea that you should just set them loose and then don't bother to check them for a longer time doesn't make a whole lot of sense to me, especially if you are doing the job yourself. The reason that you set them on the loose side is so you don't have to adjust them too soon. I'd still check them at the same intervals, as that helps with determination of wear rate.

It takes much practice with these things, same for mic's & calipers, etc. to develop the proper 'touch' to use them accurately. Far too easy to gain or loose a mill (.001") just in 'feel' alone. Perhaps that's whay they call it a 'feelers' gauge??

Go - no go is the way to go!!

 

[mcatrophy]

... set them loose and then... ...The reason that you set them on the loose side is so you don't have to adjust them too soon. ...

When I was very young, and probably when materials and hardening and oil weren't as good as they are today, there was a consensus of opinion that too loose adjustment led to premature wear of the cams and cam followers 'cos they hit harder (so making more noise). Don't know if that still applies today. Personally I'd aim for the middle of the range if I was in there already.

 

[Constant Mesh]

Both the intake and exhaust valves open 8 mm, or 315 thousandths of an inch. It's amazing just how little they move up and down, just 5/16".

So plus or minus 2 thousandths of clearance probably has a very minor effect on power output.

2 / 315 = 0.63 percent, less than 1 percent

But if you can gain a slight power edge just with the clearance adjustments you might as well go for it. Still believe the factory techs purposely set the intake clearances on the tight side for this reason.

 

[Fred W]

Both the intake and exhaust valves open 8 mm, or 315 thousandths of an inch. It's amazing just how little they move up and down, just 5/16".

So plus or minus 2 thousandths of clearance probably has a very minor effect on power output.

2 / 315 = 0.63 percent, less than 1 percent

Or, looking at it in the native metric, the entire spec range is .07mm on that ~8mm total opening. Even if you went from one edge of spoec to the other you wouldn't be making a 1% change in lift. The duration angle change would be a larger change multiplied by the ramp of the cam.

But if you can gain a slight power edge just with the clearance adjustments you might as well go for it. Still believe the factory techs purposely set the intake clearances on the tight side for this reason.

I'm inclined to agree with you on the intake side, but maybe not so much on the exhaust.

On my first check my intakes were all somewhere between .006" and .007" (.006 fit and .007 wouldn't), at the tight end of spec range, and from what I've seen that seems to be the norm. OTOH, the exhausts were all between .008 and .009, or pretty close to the middle.

Getting ready to do my 2nd check soon.

 

[charismaticmegafauna]

But if you can gain a slight power edge just with the clearance adjustments you might as well go for it. Still believe the factory techs purposely set the intake clearances on the tight side for this reason.

I'm inclined to agree with you on the intake side, but maybe not so much on the exhaust.

On my first check my intakes were all somewhere between .006" and .007" (.006 fit and .007 wouldn't), at the tight end of spec range, and from what I've seen that seems to be the norm. OTOH, the exhausts were all between .008 and .009, or pretty close to the middle.

The intake side is also the side less benefitted by valve cooling due to 'time on seat' -- being bathed in fresh, cool, intake mixture.

 

[smithpa68]

I'm inclined to agree with you on the intake side, but maybe not so much on the exhaust.

On my first check my intakes were all somewhere between .006" and .007" (.006 fit and .007 wouldn't), at the tight end of spec range, and from what I've seen that seems to be the norm. OTOH, the exhausts were all between .008 and .009, or pretty close to the middle.

Getting ready to do my 2nd check soon.

I just checked mine for the first time tonight and I saw the same. Two intakes were a .006. Definitely felt a like a perfect .006 with a bit of friction. The others were easy .006 but .007 would not fit. Exhausts were the same as your between .008 and .009. I assume in spec... is in spec. Button it up right?

 

[MCRIDER007]

I'm inclined to agree with you on the intake side, but maybe not so much on the exhaust.

On my first check my intakes were all somewhere between .006" and .007" (.006 fit and .007 wouldn't), at the tight end of spec range, and from what I've seen that seems to be the norm. OTOH, the exhausts were all between .008 and .009, or pretty close to the middle.

Getting ready to do my 2nd check soon.

I just checked mine for the first time tonight and I saw the same. Two intakes were a .006. Definitely felt a like a perfect .006 with a bit of friction. The others were easy .006 but .007 would not fit. Exhausts were the same as your between .008 and .009. I assume in spec... is in spec. Button it up right?

RIGHT!

 

[fat kid]

Might be offtopic, but how often factory recommends to adjust valves?

 

[mcatrophy]

Might be offtopic, but how often factory recommends to adjust valves?

In the UK it's every 24000 miles. Don't know about what they say in the 'States, but it's in your Owner's Manual.

 

[Fred W]

Yup, 24k miles here in the USA too. And the miles are even the same length.

Many of us just do them on the 25k's, and oil changes on the 5k's, as it makes it all easier to remember.

 

[mcatrophy]

... And the miles are even the same length. ...

But you do have many more of them.

 

[MCRIDER007]

Yup, 24k miles here in the USA too. And the miles are even the same length.

Many of us just do them on the 25k's, and oil changes on the 5k's, as it makes it all easier to remember.

Really? Every owners manual and FSM I have read said "Every 26,600 mi (42,000 km)", not that the precise miles matter that much.

 

[mcatrophy]

Yup, 24k miles here in the USA too. And the miles are even the same length.

Many of us just do them on the 25k's, and oil changes on the 5k's, as it makes it all easier to remember.

Really? Every owners manual and FSM I have read said "Every 26,600 mi (42,000 km)", not that the precise miles matter that much.

Couple more manuals for you to read

.

A 2004 (only km in this one):

Or this (2014, UK)

 

[HotRodZilla]

Right. 26,000 miles.

 

[MCRIDER007]

Yup, 24k miles here in the USA too. And the miles are even the same length. Many of us just do them on the 25k's, and oil changes on the 5k's, as it makes it all easier to remember.

Really? Every owners manual and FSM I have read said "Every 26,600 mi (42,000 km)", not that the precise miles matter that much.

Couple more manuals for you to read .

Maybe I should have said every owners manual and FSM for US owners I have read...since I was referring to US models.

 

[mcatrophy]

Yup, 24k miles here in the USA too. And the miles are even the same length.

Many of us just do them on the 25k's, and oil changes on the 5k's, as it makes it all easier to remember.

Really? Every owners manual and FSM I have read said "Every 26,600 mi (42,000 km)", not that the precise miles matter that much.

Couple more manuals for you to read .

Maybe I should have said every owners manual and FSM for US owners I have read...since I was referring to US models.

Yup, just found the page in the US workshop manual for the '06, it does indeed say 26,600 mi (42,000 km).
Must be extended that bit in the US because they want you to change the oil and filter more often than in Europe (oil every 4000 as opposed to 6000 miles). Strange, isn't it?

 

[Fred W]

Ooops. Yeah, the spec is 26.6k not 24k miles that I am ignoring. So I guess our miles are shorter.

Why the same identical bike would have two different valve check specs, depending only on where it was sold is a mystery.

 

[MCRIDER007]

Ooops. Yeah, the spec is 26.6k not 24k miles that I am ignoring. So I guess our miles are shorter.
Why the same identical bike would have two different valve check specs, depending only on where it was sold is a mystery.

The valve check for the C14 (and the ZX-14) is 15K in the US and Canada and 24K for the rest of the world. There was speculation on the C14 forum that is was tied to the emissions certification and that Kawasaki decided to take the easy way out and just certify the shorter valve check interval.

I would like to know what drives the oil change intervals for the FJR (and the S10) which is 4K in the US and 6K about everywhere else. I don't see how that could be influenced by emissions requirements.

 

[Fred W]

My guess is that all of these "specs" are decisions made by the various country/regional marketing groups of the company, and not at all grounded in any scientific or engineering based reasons.