Valve shimming process

Posted: Sun Jun 07, 2015 12:21 am

I've been searching around for a while now and I remember reading to do shims when the motor is at TDC and the pulse Gen is at F. And does this also work for intake and exhaust valves? If anyone can either explain or provide a link i would be greatful.

Posted: Sun Jun 07, 2015 3:26 am

Richlkyl000 wrote:

I've been searching around for a while now and I remember reading to do shims when the motor is at TDC and the pulse Gen is at F. And does this also work for intake and exhaust valves? If anyone can either explain or provide a link i would be greatful.

To be on the safe side, there are things you can do to hurt your bike when adjusting the shims. Only take out 1 at a time and do not turn the engine with a shim out of the bucket.

Here are links to some valve adjustment instructions and tools:

Shim Swap Video:
http://www.cb1100f.net/Other/misc/Shimswap.wmv

Humorous Procedure But Good:
http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=822

Valve Adjust Instructions with Pictures Conversion Spreadsheet:
http://www.cb1100f.net/Other/valvechart/papalukervalveadjust.pdf
http://www.cb1100f.net/Other/valvechart/papalukervalveworksheet.xls

Chart I created to record before and after shim sizes:

Picture of the tools for valve adjustments:

Dave

Posted: Sun Jun 07, 2015 12:11 pm

I find the quickest way to check is to pull the plugs, and take a "long" small diameter plastic straw and put it down into the #1 cylinder, and then rotate the engine until the straw comes up fully to TDC (neither rises or falls), and with the cam lobes on the exhaust and intake facing away, check the clearances. Go to #2, and do the same, and then #3, and then #4. I find this quicker than rotating and trying to line up the tang on the timing unit. After recording the clearances, focus one at a time on the shim that needs attention. Take out shim, measure, replace with one that gives you the correct clearance. The masses believe .005" should be the correct clearance.

Posted: Sun Jun 07, 2015 12:38 pm

petrat wrote:

I find the quickest way to check is to pull the plugs, and take a "long" small diameter plastic straw and put it down into the #1 cylinder, and then rotate the engine until the straw comes up fully to TDC (neither rises or falls), and with the cam lobes on the exhaust and intake facing away, check the clearances. Go to #2, and do the same, and then #3, and then #4. I find this quicker than rotating and trying to line up the tang on the timing unit. After recording the clearances, focus one at a time on the shim that needs attention. Take out shim, measure, replace with one that gives you the correct clearance. The masses believe .005" should be the correct clearance.

I like that straw idea, makes things even easier.....

Don't forget Sonic's simple conversion so calculations aren't needed converting from thousands of an inch to hundreds of a mm....Every .002" changes one shim size .05 mm

Ex: Measure clearance on a valve at .003" with a 2.75 mm shim in place, a 2.70 (next size down) mm shim should give .005 and a 2.80mm would give .001 (obviously too small).

I always recheck my actual measured clearance after substituting a marked shim to verify the shim size as marked.

You should still use the chart to record and keep records of what shim is where, and what the clearances were, and how they are moving for each valve but if you understand the idea you don't have to calculate anything and shimming is easy. Obviously this idea only applies to Americans that think in thousandths of an inch.

Posted: Sun Jun 07, 2015 5:12 pm

Well this way makes loads more sence on how to do it I've done it by the book but I'm sure I still have a loose valve. I have gone through and checked 2 times and still no change gonna try your guys way.

Posted: Mon Aug 03, 2015 5:01 pm

Posting for purposes of locating when needed

Posted: Mon Aug 03, 2015 5:41 pm

An even easier way to calculate shim replacement size is to buy metric feeler gages. Then you only have to add or subtract.

Posted: Fri Aug 07, 2015 1:24 am

You can check clearance at TDC but be careful opening valves to replace the shim when piston is at TDC. The valves can easily hit the piston crown.

Posted: Fri Aug 07, 2015 2:24 pm

Good info guys!

Posted: Fri Aug 07, 2015 5:34 pm

I want to pop in and add that although some like the Motion Pro tool to open valves....I prefer the original Honda tools as they do only one at a time. It is terribly easy to get distracted and lose your place having two valves open.
Do one....check it...replace...move on.
Also.....going from "0" numbers to "5" is .002 (I.E. 260 to 265) Half number (I.E. 260 to 262 or 265 to 268) are about .001
You may not get them spot on.....no matter.....lean to the "fat" or loose side and they will beat themselves in over time.

Have fun.....take your time.....

Jebby

Posted: Fri Aug 07, 2015 7:38 pm

Maybe its because Im paranoid, but I always check the shim thickness with a mic (caliper is close enough). Just because it says 275, doesn't mean its 275. Ive found some at 272, and some at 278, etc. when looking for that 275.

When I check, I use an American feeler. And do the math. Its not that tough. 2.75mm= .1083, If I need .002, its .106=2.699, or a 2.70 shim. Close enough. Knowing a 2.69 would be ideal, I look for a worn 2.70 with a "good" side to put next to the cam. But @ .005 +- .001..there's room to play.

Posted: Fri Aug 07, 2015 9:59 pm

TomStrasser wrote:

An even easier way to calculate shim replacement size is to buy metric feeler gages. Then you only have to add or subtract.

+1

CB1100F Joined: Feb 17, 2009 Posts: 2105 Location: Oz

Shawn_Mc wrote:

Maybe its because Im paranoid, but I always check the shim thickness with a mic (caliper is close enough). Just because it says 275, doesn't mean its 275. Ive found some at 272, and some at 278, etc. when looking for that 275.

Not paranoid. It's good practice because as you say, the shims are rarely right on the marked size.

Shawn_Mc wrote:

When I check, I use an American feeler.

Ahem...imperial!

Posted: Sat Aug 08, 2015 2:32 am

DonR wrote:

Ahem...imperial!

Hey hey hey! It could be American, but it's probably Chinese.

Posted: Sat Aug 08, 2015 2:58 am

genesound wrote:

DonR wrote:

Ahem...imperial!

Hey hey hey! It could be American, but it's probably Chinese.

Snap on, brother. Cool

Posted: Sat Aug 08, 2015 8:23 pm

Snap-On do metric feeler gauges, they do over here anyway Razz

I'll be using metric gauges when I do mine, doubt I could find gauges in .001"s anyway.
Thing is it's so simple/stupid with metric gauges.
Everything on the bike is in metric. The shims are metric.
Measure the gap in metric and the shim in metric, then it's simple arithmetic to figure out what size shim you need, in metric Cool

Posted: Sun Aug 09, 2015 1:34 am

Simon_CB900 wrote:

Snap-On do metric feeler gauges, they do over here anyway Razz

I'll be using metric gauges when I do mine, doubt I could find gauges in .001"s anyway.
Thing is it's so simple/stupid with metric gauges.
Everything on the bike is in metric. The shims are metric.
Measure the gap in metric and the shim in metric, then it's simple arithmetic to figure out what size shim you need, in metric Cool

+1. Pretty simple really.........

Posted: Sun Aug 09, 2015 3:46 pm

1100russ wrote:

Simon_CB900 wrote:

Snap-On do metric feeler gauges, they do over here anyway Razz

I'll be using metric gauges when I do mine, doubt I could find gauges in .001"s anyway.
Thing is it's so simple/stupid with metric gauges.
Everything on the bike is in metric. The shims are metric.
Measure the gap in metric and the shim in metric, then it's simple arithmetic to figure out what size shim you need, in metric Cool

+1. Pretty simple really.........

I cannot and will not convert to metric in my head to do these......
I "see" .005-.006 in my minds eye and that is how it goes down.
Too many American engines under my belt I guess.
No matter......the cat gets skinned anyhoo.

Jebby

Posted: Sun Aug 09, 2015 7:10 pm

Don't forget Corona...

Posted: Thu Aug 13, 2015 10:26 pm

Jebbysan wrote:

1100russ wrote:

Simon_CB900 wrote:

Snap-On do metric feeler gauges, they do over here anyway Razz

I'll be using metric gauges when I do mine, doubt I could find gauges in .001"s anyway.
Thing is it's so simple/stupid with metric gauges.
Everything on the bike is in metric. The shims are metric.
Measure the gap in metric and the shim in metric, then it's simple arithmetic to figure out what size shim you need, in metric Cool

+1. Pretty simple really.........

I cannot and will not convert to metric in my head to do these......
I "see" .005-.006 in my minds eye and that is how it goes down.
Too many American engines under my belt I guess.
No matter......the cat gets skinned anyhoo.

Jebby

But ya don't have to convert to metric, it's already in metric Razz

I know whatcha mean though.
When I started school we did everything in Imperial. Then the threat of the European Common Market reared its ugly head. So we started using the metric system, to be ready when 1971 came round and Britain would be joining the club. We even changed or money from £, shillings and pennies to a pound being 100 pence.
Even now some things I can't 'see in my minds eye' in metric, mind you, there are some I can't 'see' unless I convert it to metric Rolling Eyes

Posted: Fri Aug 14, 2015 3:57 pm

Simon_CB900 wrote:

Jebbysan wrote:

1100russ wrote:

Simon_CB900 wrote:

Snap-On do metric feeler gauges, they do over here anyway Razz

I'll be using metric gauges when I do mine, doubt I could find gauges in .001"s anyway.
Thing is it's so simple/stupid with metric gauges.
Everything on the bike is in metric. The shims are metric.
Measure the gap in metric and the shim in metric, then it's simple arithmetic to figure out what size shim you need, in metric Cool

+1. Pretty simple really.........

I cannot and will not convert to metric in my head to do these......
I "see" .005-.006 in my minds eye and that is how it goes down.
Too many American engines under my belt I guess.
No matter......the cat gets skinned anyhoo.

Jebby

But ya don't have to convert to metric, it's already in metric Razz

I know whatcha mean though.
When I started school we did everything in Imperial. Then the threat of the European Common Market reared its ugly head. So we started using the metric system, to be ready when 1971 came round and Britain would be joining the club. We even changed or money from £, shillings and pennies to a pound being 100 pence.
Even now some things I can't 'see in my minds eye' in metric, mind you, there are some I can't 'see' unless I convert it to metric Rolling Eyes

I work with a LOT of metric machining, engines, etc......I know what a mm and cm look like......but for some reason I can't '
visualize valve lash in mm.....so I don't.

Jebby

Posted: Fri Aug 14, 2015 8:33 pm

Yeah, too many years of doing it in Imperial. And my analog dial calipers are imperial too, and much faster than using a digital... the dial caliper has more "feel" too.