Valve clearance

[JATO]

I checked the valve clearance on my '78 1K tonight and found all of them to be less than .0015", that's as small as my feeler gauge set goes. In my manual it calls for .001"-.003". My question is, should I reshim or leave them be? The bike has around 36,000 miles on the engine(uncertainty in milage due to multiple broken speedo cables and non original gauge pack).

I should find a feeler gauge that goes down to .001" it be certain.

 

[Nessism]

I checked the valve clearance on my '78 1K tonight and found all of them to be less than .0015", that's as small as my feeler gauge set goes. In my manual it calls for .001"-.003". My question is, should I reshim or leave them be? The bike has around 36,000 miles on the engine(uncertainty in milage due to multiple broken speedo cables and non original gauge pack).

I should find a feeler gauge that goes down to .001" it be certain.

If the valves are all tight you should change the shims. They tighten with usage and tight valves leads to damage. Your .0015 gauge is fine, get them to the high end of the spec range.

 

[doctorgonzo]

Rule of thumb is too loose is better than too tight. If they are at the low end of spec I'd re-shim them. Mine (in metric) is .03 to .08. My gauge only goes to .04. If they were tighter than .04 I took them down one shim size even if it made them too loose.

 

[Steve]

Since you are about to embark on this wonderful task, send me an e-mail with "valve adjust spreadsheet" in the subject and I will send you a copy of my spreadsheet that helps you do the math and figure out what shims you need.

When you adjust your valves the first time, you will need to look at all the shims to see what size they are. (My spreadsheet helps you keep track of them.) You may find that you can move some of your shims around to where they are needed and minimize the number of shims you need to buy. I have seen 6 of the 8 valves out of adjustment, but by moving shims around, we only needed to buy 2 shims.

Good luck on finding a feeler gauge smaller than 0.0015". As Nessism and DoctorGonzo have said, your valves are happier at the looser end of the range anyway, so when they get to where your 0.0015" gauge won't go in, changing the shim will take it up between 0.003" and 0.0035", so you will be fine.

.

 

[Nessism]

How about a Snap-On feeler gauge set that goes down to 0.001" for $5.55 shipped? Order two! http://buy1.snapon.com/catalog/item...&group_ID=1122&store=snapon-store&dir=catalog

 

[Steve]

OK, I didn't say they weren't out there, I just said "Good luck finding one."

Thanks for the link. 8-[

.

 

[BassCliff]

A slappy valve is a happy valve

A slappy valve is a happy valve

Hi Mr. Jato,

I concur with the wisdom stated thus far. I would also suggest that you invest in a metric feeler gauge. It makes it easier (for me, anyway). If all of your valves clearances are smaller than .0015 inches, chances are that some are too tight and out of spec.

Thank you for your indulgence,

BassCliff

 

[JATO]

Thanks for all of the replies. The chart I have is out of the Haines manual. The job write-up and the chart are very well laid-out and easy (for me at least) to follow even though they are written in the Queen's English instead of our good old American version of the language.

Now another question. Does anyone have a good drawing, with dimensions, of the valve compressor tool that's used to facilitate the shim removal?

 

[Guest]

Now another question. Does anyone have a good drawing, with dimensions, of the valve compressor tool that's used to facilitate the shim removal?

do a search, it was posted not so long ago
or buy it from www.z1enterprises.com for $15
it can also be done with a flat head screwdriver used as a lever
or by tying zip ties through the spark plug holes

 

[JATO]

WHat am I doing wrong

WHat am I doing wrong

This is what I have as far as shims:

Cyl# Pos Current shim New shim from chart

1 Exh 2.85mm 2.80mm

1 Int 2.70mm 2.65mm

2 Exh 2.80mm 2.75mm

2 Int 2.65mm 2.60mm

3 Exh 2.85mm 2.80mm

3 Int 2.70mm 2.65mm

4 Exh 2.85mm 2.80mm

4 Int 2.65mm 2.60mm


I moved around the ones I could (positions 1 exh, 1 int, and 3 int) and there still wasn't any clearance. I even put the 2.65 shims in the positions that had the 2.85 shims, which is a .20mm difference, and still no clearance. Am I doing something wrong? The engine is cold and I positioned the cam lobs as the manual states and yet I'm getting nothing. Are my valves that jacked up? Is a valve job required at this point or do I just have to take it into a shop that has access to all of the shims and let them have a go at it?

 

[lurch12_2000]

I checked the valve clearance on my '78 1K tonight and found all of them to be less than .0015", that's as small as my feeler gauge set goes. In my manual it calls for .001"-.003". My question is, should I reshim or leave them be? The bike has around 36,000 miles on the engine(uncertainty in milage due to multiple broken speedo cables and non original gauge pack).

I should find a feeler gauge that goes down to .001" it be certain.

.0015" is .038mm.
So I wouldn't bother getting a smaller feeler gauge and just go one size down on your shims. But if it's real tight you might be going down 2 sizes.
One size down will bump you up approx .05mm in clearance. I say approximately because there could be some variation from the measurement stamped on the shim.

.001"-.003" = .03mm-.08mm
I would stay with mm as it is easy to get confused and the shims are measured in mm anyway. Look at this thread and you can see already that we're jumping between mm and inches.

 

[lurch12_2000]

This is what I have as far as shims:

Cyl# Pos Current shim New shim from chart

1 Exh 2.85mm 2.80mm

1 Int 2.70mm 2.65mm

2 Exh 2.80mm 2.75mm

2 Int 2.65mm 2.60mm

3 Exh 2.85mm 2.80mm

3 Int 2.70mm 2.65mm

4 Exh 2.85mm 2.80mm

4 Int 2.65mm 2.60mm


I moved around the ones I could (positions 1 exh, 1 int, and 3 int) and there still wasn't any clearance. I even put the 2.65 shims in the positions that had the 2.85 shims, which is a .20mm difference, and still no clearance. Am I doing something wrong? The engine is cold and I positioned the cam lobs as the manual states and yet I'm getting nothing. Are my valves that jacked up? Is a valve job required at this point or do I just have to take it into a shop that has access to all of the shims and let them have a go at it?

Dropping 4 sizes and still no clearance??...yes I think you're doing something wrong!

 

[JATO]

I have no idea what I could be doing wrong, I'm following the tech data to the letter. Are the cam followers hydraulic? Do the followers have to be flat? There's zero sludge in the engine, the internals look shinny and new. 4 years ago I did a cylinder leak down test with the current shims in place and I was getting 0% leakage. I'm thinking of buttoning it all back up and doing another leak down test and seeing where it it's at now. Either that or just running it as is and forgetting about it. I'm an FAA certified A&P with most of my experience on recips, so I know my way around engines, but this is confusing the hell out of me.

 

[BassCliff]

I got pictures

I got pictures

Hi Mr. JATO,

Please visit my little BikeCliff website and take a look at the valve adjustment pictorial guide. Maybe it will help. Keep us informed.


Thank you for your indulgence,

BassCliff

 

[JATO]

The procedure I followed is identical to your write-up, BassCliff. What if I pull a shim, measure the clearance between the follower and the cam, subtract the proper clearance and use the remainder to figure out the necessary shim thickness? I don't think the valves on this bike have ever been adjusted in the past 30 years.

 

[BassCliff]

Another thought

Another thought

Hi Mr. JATO,

The first time I adjusted my valves I had to go down 2 sizes on a couple of shims. I don't think the valves had ever been adjusted (13,800 miles when I bought the bike). After you insert a smaller shim, are you spinning the motor a few times to "seat" the new shim in the bucket, then re-measure?


Thank you for your indulgence,

BassCliff

 

[Guest]

if you re going two sizes down on shims and still not getting enough clearance id assume you re doing something wrong
id start over
use mm feeler gauges to avoid confusion
you need to have an extra shim when swapping them around so no bucket is left without a shim while you re turning the camshafts

measuring the distance between the bucket and the shaft is not going to work as its practically impossible to get an accurate measurement of that space

as there are some discrepancies in the methods used, make sure that the 2 adjacent lobes are away from the shim at the same time (ie, neither of the two is pressing on the valve)

 

[JATO]

I'm spinning the crank, on the cylinders I could do so I went down 4 sizes, and I did start over and put everything back the way it was. I'm going to let it go for now since it was running like a rare hair last fall and come back to it when I regain some patience.

 

[bwringer]

Well, ignoring the problem certainly won't make it go away... I'd reallllllllllly recommend that you either figure out what the problem is with your procedure or get the clearances set correctly pronto.


I have a 2.15mm shim, the thinnest available, I use in baffling zero-clearance situations like this. If it's still zero with that shim in place, the valve is burned. With the 2.15mm shim in place, you can measure the (hopefully) large gap and go from there.

I have needed to go down four or five shim sizes in a few cases of neglected bikes, so yes, it can definitely happen.

The only other thing I can think of is that two or more of your feeler gauges are sticking together. This seems to happen to me at least once every time I check valves, and I'm sure it's something you've encountered before as well. A .0015" feeler is pretty much just a floppy slice of foil you can dang near see through. Just a thought.

 

[Guest]

if you think its running really well and 4 sizes down on shims is not enough, well somethings definitely wrong as these two things are incompatible
for the bike to run properly valves have to be in spec
you can notice a difference in how the engine runs when only a few shims that are out of spec by just 1 size are brought back to spec...

neglect in this department can lead to expensive damage