ok to check valve clearance with cam lobes up instead of TDC?

[Razorback]

I tried using T1 and T2, but could not get a feeler gage under the lobes.

Isn't it just as good to point the lobe straight up so there is no pressure on the valve train and then slip the feeler gage under there?

 

I got readings similar to Droneh8tr, except mine are a tad tighter, therefore my numbers look believable.

 

Was my measurement method acceptable?

 

Thanks, Kenny

[Peder_y2k]

If you couldn't fit a feeler guage , then your clearance is "zero". Yes, cam position makes a difference because of the way it is ground. Use the T1 and T2.

-Pete, in Tacoma WA USA

[MasterGuns]

At the SE Texas Maintenance Day, two 1st Editions had their valves adjusted. The cam lobe was positioned 180 degrees up from each valve shim. Positioning using T1 and T2 was not used and the outcome was great. The lobe was positioned directly between the valve cover bolt locations which is directly 180 degrees from the top of the valve shim.

[djh3]

Depending on how long the bike has sat without running you may want to try this. Pull the plugs so it will roll thru easier, and a drop or so of oil on cam lobe and rotate thru a few times. Its probably not going to change your reading but may help the gauge slide in a bit easier. But read thru the thread on valve clearance, I thought it said to start at TDC and then work your way around the engine, The cams should be almost straight away from the tappet at the TDC marks.

[MiCarl]

TDC on the compression stroke is the place where you CAN measure both the intake and exhaust clearance. Personally, I prefer to turn the engine until the lobe on the one I want to measure points away from the valve. I think it's faster than trying to line up everything perfectly to do intake and exhaust simultaneously.

[Razorback]

I figured as long as I'm measuring only between the base circle of the cam lobe and the shim, I should get the same result as at TDC, when the valves should be closed (lobe base circle above shim, no lobe ramp/flank involved)

 

It's certainly easier to just point the lobes skyward and measure for each set of valves.

 

I'll post my results shortly, which shows all are tight.

[Squeeze]

Since this Job is already a done Deal, it's pretty pointless to discuss the Issue afterwards.

 

But anyway, no, it's not ok to MEASURE something in a Place which is not the Reference Point for the Specs of the Manufacturera and rely on the Outcome. If the Manufacturer would have tought it's a good Idea to go for the lowest Point on the Cam, they would have described the Procedure and the Lash this Point.

 

The Specs on Valve Lash are given for the Reference Point, using the lowest Point on the Cam MIGHT give you a close Result, but the Cams might be under Tolerance in the low Area and you have the Lash set too tight with this. Although i never thought about going the easy Way, i don't think there's only a small Difference inbetween the specified Point and the lowest Point on the Cam. I venture the guess to say it's at least 10 or 15 Percent Difference.

 

 

i.E. ....it's pretty much the same as saying it's 20 Degrees outside ...

 

What Degrees are you talking about ? cold 20 Fahrenheit, nice 20 Celsius or even very cold 20 Kelvins? Same Value, but a huge Difference without naming the Scale.

 

 

If you say, all Valves are tight, it's might be an Indication of a wrong Reference Point, or did you use metric Values to measure Thickness with an "inch" feeler Blade ?

[steamer]

I checked mine using both procedures, the reading where the same. It's easier to just point the lobe's straight up.

[Razorback]

Since this Job is already a done Deal, it's pretty pointless to discuss the Issue afterwards.

 

I've only measured "my way". It's not a done deal yet. Everything is still open as i confirm that my method is valid, or terribly unreliable. i can still attempt to remeasure with the timing timing marks As it is, I see the need to get the tools and change the shims anyway so it's still ready for remeasuring.

 

But anyway, no, it's not ok to MEASURE something in a Place which is not the Reference Point for the Specs of the Manufacturera and rely on the Outcome. If the Manufacturer would have tought it's a good Idea to go for the lowest Point on the Cam, they would have described the Procedure and the Lash this Point.

 

Partly depends on why they specify that reference point IMO, but i do generally agree with the guy that built the thing. It's just simpler to watch the cams rotate and measure after they've relieved the pressure from the pad, if my assumptions are correct based on standard cam lobe geometry. If they're still contacting the shim, i can't slide the feeler gage under there, and i still have contact on the timing marks. i don't understand why i have zero gap on the timing marks, T1 or T2. Is it reasonably common to have NO gap on a low mileage bike that was running fine before a carb went goofy?

 

The Specs on Valve Lash are given for the Reference Point, using the lowest Point on the Cam MIGHT give you a close Result, but the Cams might be under Tolerance in the low Area and you have the Lash set too tight with this. Although i never thought about going the easy Way, i don't think there's only a small Difference in between the specified Point and the lowest Point on the Cam. I venture the guess to say it's at least 10 or 15 Percent Difference.

]

 

10% of my largest gap is only .0006, which our feeler gauges won't do, nor can we shim for that type of difference (I'm hearing that the shims are in .005 increments anyway).

So maybe that type of difference won't matter too much?

 

 

 

 

If you say, all Valves are tight, it's might be an Indication of a wrong Reference Point, or did you use metric Values to measure Thickness with an "inch" feeler Blade ?

Specs are given in both SAE and Metric, so although I can convert mm to inch and back, I didn't have to.

 

I appreciate the discussion (that is why i posted after all), keep it coming.

 

 

My measured values, with lobes up, are in the attached file.

[Black wing]

you wondering why your getting a 0mm reading is it could very well be true. these valve wear backwards so as the valve wears down it closes the gap to the cam and a smaller shim needs to be installed. so if it hasn't been done in a very long time such as mine was when i got it it could be riding the cam all the way around the lobe

[Squeeze]

Oh sorry, i misread your Post.

 

Well, if you can't get the Feeler Gauge inbetween in any Position, you have to change to a thinner Shim before you can actually check and determine the Lash. IF you get the Shim out, that is ...

 

I wish you much of Luck and Coolness, that's not funny at all. If you can't get the Bucket down enough to slide the Shim out, you have to undo the Cam Bearing Caps and loosen the two Bolts on the Cam Sprocket. This should loosen Things up just enough to pull the Shims. Nothing i envy you ...

 

It's nothing unusual, the Way these Engines are made, the Lash get tighter and tighter over Time and there nothing to "hear" at all. The Valve hammer the Seat into the Head and there nothing you can do about it except check and bring in thinner Shims.

 

A good running Bike is relative thing, it will stop running "good" when the EX-Valves and their Seats are burned up enough and start to drippin' into the Headers.

[Razorback]

Oh sorry, i misread your Post.

 

Well, if you can't get the Feeler Gauge inbetween in any Position, you have to change to a thinner Shim before you can actually check and determine the Lash. IF you get the Shim out, that is ...

 

I wish you much of Luck and Coolness, that's not funny at all. If you can't get the Bucket down enough to slide the Shim out, you have to undo the Cam Bearing Caps and loosen the two Bolts on the Cam Sprocket. This should loosen Things up just enough to pull the Shims. Nothing i envy you ...

 

It's nothing unusual, the Way these Engines are made, the Lash get tighter and tighter over Time and there nothing to "hear" at all. The Valve hammer the Seat into the Head and there nothing you can do about it except check and bring in thinner Shims.

 

A good running Bike is relative thing, it will stop running "good" when the EX-Valves and their Seats are burned up enough and start to drippin' into the Headers.

 

oh no, I got measured gap, as long as I was measuring between the base circle of the cam lobe and the shim, it's just that it wasn't always possible when lined up with the timing marks. It's not riding the lobe all the way around.

 

I think i'll line up T1 and take a picture of the cams/shims and then T2 and take a picture so you can see what i'm talking about. I still don't understand it.

 

It was running great (as far as i know) before I had carb issues and took it off the road for a while.

It cranked up and ran so-so (attributed to carb pilot jet issues) just 2 weeks ago before i yanked off the carb bank. i figured I had read enough times about checking my valve clearance that i should make sure that's right.

[dingy]

Attached is a Microsoft Excel 2003 spreadsheet that can be used as an aid in selecting replacement valve shims.

 

This should work for 1983 through 2013 models, I did not see any variances in the sizing charts in the service manuals.

 

1st sheet in each file is in Metric format.

 

2nd sheet in each file is in Inch format.

 

I expanded upon the valve clearance charts that are in the service manuals to include the shims end in 2 and 8. The reason for this is that these shims can be reused in the bike if available. I don't believe you can buy the --2 and --8 sizes.

 

Screen shot below shows cylinder 2 area. The only cells that are selectable are the "Shim in Now" & "Measured Clearance" data fields.

 

The "Shim in Now" field will only accept valid shim sizes. There is a pull down menu for valid sizes or size can be keyed in. The only other value that is accepted as input is a zero. I included this to set chart to neutral setting.

 

The "Measured Clearance" field has no error checking built in. Use millimeters on Metric sheet or inches on Inch sheet. The decimal point needs to be entered, the "mm" or "in" does not need to be entered.

 

Below the "Measured Clearance" field is a calculated field for "Shim Needed". This field will display the correct shim size to set valve clearance to the high end of acceptable range.

 

Next is "Expected Clearance" field. This is a calculated field to show what valve clearance should be with the shim size shown in "Shim Needed" field.

 

Next is "2nd Choice Shim" field. This field will display the next larger size shim that will work. This shim may be selected due to "Shim Needed" is an odd size or not available. This shim will set valve clearance to the low end of acceptable range.

Next is another "Expected Clearance" field. This is a calculated field to show what valve clearance should be with the shim size shown in "2nd Choice Shim" field.

 

In the upper right hand example, the lower "Expected Clearance" field is highlighted in Red. This will happen when any of the calculated sizes fall outside of acceptable range.

 

If value cannot be calculated the "Shim Needed" field will be blank and error will display in "Second Choice Shim" field. This will happen if an out of range clearance value is entered.

 

The two right hand charts in screen shot do not have data entered in so there are errors shown.

 

This should print out on 8 1/2" x 11" paper very readable.

 

This is just an aid for shim selection.

 

Verify clearances if you use this after shims are installed.

 

There is a separate spreadsheet for Ventures & Vmaxs, the Vmax exhaust valves are different settings than a Venture.

 

Gary

[Neil86]

I think there might be a simple explanation for what you encountered.

The engine requires 2 full crankshaft revolutions to get the 4 cycles

(intake-compression-power-exhaust).

 

So for a particuliar cylinder ie #1, there are 2 times its at TDC during the 4 cycles

one is TDC compression when both intake and exhaust are closed

one is at TDC exhaust (360 degrees later) when both slightly open...and you

will have zero clearance.

 

If you started at TDC #1 mark on the exhaust stroke and followed the rotations

in the manual, you'd hit the TDC exhaust on the rest of the cylinders too.

 

As you rotate crankshaft CCW, after intake valve on #1 cylinder (left rear) closes

when the TDC 1 mark lines up, you'll be at TDC compression on that cylinder.

[Razorback]

That was it Niel86

 

As luck would have it, and not realizing what was required, I would line up on T1, scratch my head because the lobes didn't look right (position) and decide to spin it around again, overshoot the T1 mark and have to make another revolution to line it up again, on the wrong stroke, same as I started.

 

Boy do i feel silly now. I was able to read every clearance per the specified method, with a couple .001" changes to some of my numbers.

 

Now I still need a shim tool, or any other DIY method to depress the buckets to remove the shims.

 

I'll post up my numbers shortly.

[Razorback]

Here is the spreadsheet on my correctly checked numbers.

 

The new numbers are highlighted in yellow, not much difference. I'm still mostly out of spec.

 

I'll have to get the shims out to see where I need to go from here.

 

I'll resist the urge to put the carbs back on until I get done with valves. I had them off going through them, then decided to check the valves.

 

I will probably go ahead and do the forks seals though while I wait on a tool, and then correct shims.

 

Thanks to everyone for their input.

[Peder_y2k]

Tip: Never rotate the cam without a shim in place.

Don't ask me how I know! BTW, I have a handy little tool for use if the cam drops into an empty shim bucket.

-Pete, in Tacoma WA USA

[Razorback]

Perhaps I'll throw my wrench across the yard after I get the cam set to pull a set of shims.

 

Rinse and repeat.

 

😃

[Razorback]

Tip: Never rotate the cam without a shim in place.

Don't ask me how I know! BTW, I have a handy little tool for use if the cam drops into an empty shim bucket.

-Pete, in Tacoma WA USA

 

This has me thinking....

With the prospect of re-using many of my shims by moving them to other positions, How will i accomplish that without first having any spare shims to put in place while i move them around?

[Neil86]

The tool holds 2 adjacent valves open at same time so you can swap those two, otherwise

you will need a spare, and you probably would want a thin shim so it can be moved anywhere easily(ie a 260 or 262).

A lot easier using a kit with a selection if you can access one.

[Razorback]

Tptjg

 

 

Sent from my iPhone using Tapatalk

[RandyR]

This has me thinking....

With the prospect of re-using many of my shims by moving them to other positions, How will i accomplish that without first having any spare shims to put in place while i move them around?

 

Measure them all first. determine which need to be replaced and remove 1 at a time those that will need replacing and see what the current size is, then replace the current shim.

 

This will give a list of what shims you will need to replace and which will become eligible to be moved elsewhere.

 

You would have to be very lucky to just be able to shuffle things around without a spare, and it could get very complicated. Buying a couple 2.65 shims in advance is the most likely way to get the shims you will ultimately need (60% of the time this would do the trick).

 

OR. borrow my shim & tool kit with a variety of shims in it. I only ask that any shims used up 2.70 and under be replaced. Others can be swapped around for your bikes'. And pay my postage ($8.50)

[Razorback]

Thanks for the info Randy.

I actually did what you suggest. I checked them all, bought the 13 I needed an then went back in for the replacement process.

 

I think I "pocket posted" from my phone earlier. 😄

 

 

Sent from my iPhone using Tapatalk

[jfman]

Tip: Never rotate the cam without a shim in place.

Don't ask me how I know! BTW, I have a handy little tool for use if the cam drops into an empty shim bucket.

-Pete, in Tacoma WA USA

 

Oh I know how you know

 

I had to replace a bucket on my bike from making this mistake. I wanted to swap shims from one cyclinder to the other without doing the whole musical chair dance and I nicked the edge of the bucket and had to buy a new one.

 

Remove cams and retime the bike.

[Flyinfool]

I would still like to see a pic of that "handy little tool".