Topic: valve clearance adjustments worries

[Buffo]

In trying to check the valve clearance on my 1978 cb750k8, I found it rather hard to tell if I was getting an accurite reading or not. I have to bend my feeler gauge to get it to go into the gap. the angle is rather steep. worried about feeling "drag" on the bend and not on the actual gap...

Does this make sense?

I should just put a good 45 degree bend in my gauge huh...

Don

[scondon]

I use the same flat feeler gauges you do. I set the intakes at .002  with just light resistance on the gauge. Then I check that the .003 gauge will not fit in the gap. Same with the exhaust, set with .003 - check with .004

       I also have a bent feeler gauge tool designed for the job but it only has .002 - .003 so I can't double check the exhaust and after using the above method with "flat feelers" I've come to prefer them.

[Terry in Australia]

Good advice Sean, I've used the "Go - No Go" method as explained by Sean with no problems. Cheers, Terry.

[oldbiker]

It is well worth buying or making the correct tool for this job. It consists of a central rod having a square hole to fit on the end of the adjuster screw which fits through a tubular socket  to fit the locknut. The adjuster part has a circular finger nut on the outer end which is scribed into 20 divisions. To use it, locate the two parts in position slacken the locknut, close the adjuster part up just barely finger tight and then undo it ONE division. Hold it in place and tighten the locknut. Job done.  The adjuster screw has a pitch of 1mm (.039")so one twentieth of a turn equals .002" This is the way Honda mechanics do the job and never use feeler guages.

[SteveD CB500F]

Sounds easy.  Where do you get them?

[Bob Wessner]

Good question. I wonder of these are what he is referring to? If you scroll down this page, there are a couple of URL's to special valve adjustment tools.

http://www.dansmc.com/valveclearence.htm

[oldbiker]

That's the one Bob. In my case, as I have a Myford lathe, I made the tool myself. I don't use a feeler gauge to set the tappets as I find using my 'one division' method quite accurate and even allows for any error caused by the hollowing of the valve end which a feeler cannot. I hope the diagram makes it clear that when the feeler is just gripped, the actual clearance is bigger than it should be.

[Bob Wessner]

I seem to lack the Knack for certian tuning procedures. One being hearing any subtle changes in RPM's associated with tweeking the idle jets  and the other valve adjustments. Seems when I get the slight drag and then snug up the lock nut it changes the gap. 
How much would you charge to make one of your little tools. 

[oldbiker]

It's not a matter of charge Bob. My bike is a cb400f so you must check the actual size of the square on your adjusters and the length you would need the tool to be. On mine, the square is 3mm square. The tubular spanner part is 1.7" long and the adjuster part that goes through the center is 2.4" long. How does that fit with the cb750? I think these are commercially available.  I'm in the UK but if I can find a few spare minutes, I'll make one up if you can't get one.

[luckysox]

You can buy them from  Dennis Kirk online  http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=281971&store=Main&productId=p281971&catId=1&leafCatId=11903  as long as it has 10 mm and the slot driver

[Bob Wessner]

luckysox,

Thanks for the link.

[oldbiker]

Bob, I also found the following (https://www.partsnmore.com/cat_index2.php?category=tools) which I think is the correct thing. It's not that I won't help you but I think these will be cheaper than making one and shipping it to you. all the best, John.

[Philly550K1]

on the tool front, a 10mm, "1 inch offset" box end wrench in concert with a screwdriver is pretty straightforward.  mine's a craftsman...

O
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-jon

[paul810]

hi there you can buy gauges with a 45degree bend in them cost £4to£6 from any good car parts supplier

[lohebohi]

I have seen the standard 45 degree feeler gauges.  My worry is that they will be too wide to slide in from the side of the tappet.  Do you slide the feeler gauge in from the front?  The bent feeler gauge at Sears seemed like it was too large to fit.  I guess I'll pick up a set on the way home tonight, but I would perfer some that are much smaller for this job.

[Bob Wessner]

I've found standard feeler blades too wide, so I trim them down to a more slender profile with some scissors.. just don't use your wife's sewing scissors. 

[Buffo]

I have spent some time on my tappets and have found that with a little practice it is pretty easy. I used the "go-no go" method and found it very acceptable.

I have never used one of those tools, but in doing mine with the feeler gauges and seeing first hand at how little those screws can move before the gap is too big or too small, i question how accurate those tools are. After tightening the lock nuts if the screw moved just a hair, when rechecking, I find that the gap is not proper. I find it hard to believe that those tools are as accurate as the feeler gauge, go - no go  method. Mainly because you cant actually see the screw, and having it move literally just a hair makes it out of its gap limits.

Does the gapping of the tappets need to be so accurate or would the margin of error that you may get with just using the tool acceptable?

Some tips that I have found make gapping tappets easier and more accurate:

1: use a screw driver whose tip fits snugly into the slot on the screw head so the screw has less chance of moving when tightening the lock nut.

2: Loosen the lock nut then tighten it as much as you can and still have smooth movement of the screw. This will allow a more accurate reading while adjusting the screw and have less of a chance of screw movement when tightening lock nut.

3:I like to use a screw driver with a good size handle. I have found it to hard to hold the screw in place with a smaller one when tightening lock nut.

Don

[Bob Wessner]

Spot on would be good, but slightly loose is better than too tight.

[Trevor from Warragul]

Just a note about the Dennis Kirk kits - 1 has a 9mm spanner & 4mm square adjuster, another has no 9mm spanner & a 3mm square adjuster.  With the 350/400 fours your need to buy BOTH kits (9mm spanner & 3mm square adjuster)!

Did they do this deliberately??

[Zeke]

Hey Oldie:

That tool sounds pretty cool....

On my 650 the adjuster and nut are too far in the motor to do with screwing driver and wench.  So I had to get the honda tool.  It woulda been nice for honda to have used a bit finer pitch on the adjustment screw, as you need hardly turn it at all to tighten it.

Anyway, I've found that this year I'm a valve tuning machine.  Until this last month I was riding about 700 miles/week to work and back, so this season I've adjusted my valves 4 times this year.

The go/no-go system is the way to go.  If you're a race mechanic or a machinist then maybe not, but for the rest of us it's the bomb.  Being "right-on" is a state of mind.  When you use the GNG method, you're only a few tens (.000X") off and, don't forget that you can't #$%* it up a little loose, but if it's tight your valve may not be closing all the way, or will be causing undue wear.

Use the GNG.  I can do my valves in less than an hour now.

out

Zeke

[Cvillechopper]

I've been reading up on different ways people adjust their valves but really haven't found a good discription of how snug is just snug enough.  I know there needs to be some resistance when you put the gauge in, but how much.  I'm almost ready to get my cb750K chopper project on the road and noticed a really nasty valve sound, almost a knock, while getting the timing and carbs set so I pulled the valve cover off to inspect the tappets and give more room for adjusting.  I had 4 valves that were soo far out that I could slide a .006 in with no problem.  I've got them all set to what I think is right, but really don't want to have left them too tight.  Should you have to work the gauge in or should it just slide in, no prob?

[Buffo]

dont mind the "snug". Use the "go - no go method."

Buffo

[seabird]

It's not a matter of charge Bob. My bike is a cb400f so you must check the actual size of the square on your adjusters and the length you would need the tool to be. On mine, the square is 3mm square. The tubular spanner part is 1.7" long and the adjuster part that goes through the center is 2.4" long. How does that fit with the cb750? I think these are commercially available.  I'm in the UK but if I can find a few spare minutes, I'll make one up if you can't get one.

I would dearly love to have one of your valve adjustment tools and would be willing to pay you to make one for me if you would?
I have a '75 400F gradually coming together, and my fingers always seem to be too many and too big to manage bothe feeler gauge and locknut spanner (wrench) at the same time.  How about it?

Terry (also an "Old Biker").

[Jonesy]

Bob, I also found the following (https://www.partsnmore.com/cat_index2.php?category=tools) which I think is the correct thing. It's not that I won't help you but I think these will be cheaper than making one and shipping it to you. all the best, John.

I thought there was a post about this tool from Partsnmore recently that said there was no markings or anything to adjust the valves with.. it basically took the place of the wrench and screwdriver, but you still had to mess around with the feeler gauge.

[MikeDeB]

I've been reading up on different ways people adjust their valves but really haven't found a good discription of how snug is just snug enough.  I know there needs to be some resistance when you put the gauge in, but how much.  I'm almost ready to get my cb750K chopper project on the road and noticed a really nasty valve sound, almost a knock, while getting the timing and carbs set so I pulled the valve cover off to inspect the tappets and give more room for adjusting.  I had 4 valves that were soo far out that I could slide a .006 in with no problem.  I've got them all set to what I think is right, but really don't want to have left them too tight.  Should you have to work the gauge in or should it just slide in, no prob?

When the feeler slides in it should feel the same way as if you were to slide the feeler between the pages of a phone book (about the middle).  It's almost a buttery feel, kinda hard to describe.  I use it in conjunction with the go-no-go method.  I look for the buttery feel then check with the next size feeler.  I also use an offset box wrench with a medium screwdriver.  The feelers that I use are ones made just for adjusting valves.  They're sized .002 & .003 on one and .004 & .005 on the other.  The blades are angled at about 45 degrees and are narrow.