AIRHEAD VALVE ADJUSTMENT Part 2: The Tool vs. ZipTie -w/pics

ALRIGHTY THEN. THERE SEEMS TO BE A LOT OF CONFUSION AND CONSTERNATION brought about by the use (or attempted use) of the Yamaha valve bucket holding tool for swapping shims.

So here we go with a quick supplement to the original "Airhead Valve Adjustment" http://xjbikes.com/Forums/viewtopic/t=14827.html wherein by using my spare cylinder head I can show you exactly what both methods of propping open a valve entail, and the pros and cons.

So, jumping out of that article:

When the tool is in place and working correctly, it holds down the edge of the bucket when you rotate the cam away: (Look closely just below the cam you can see the tip of the tool engaged with the edge of the bucket.)




What's going on under there is this:




Which is why, in order for the tool to do its job, it needs to be as centered as possible on the cam lobe:



You can see by the second pic if the tool isn't centered in relation to the bucket (and cam lobe) then it can't catch the edge of the bucket in the right spot. If you get the Tool centered on the cam lobe it will work every time.


WHICH BRINGS US TO:


THE "ZIP-TIE" METHOD: If you don't have access to the tool, you can use the "zip-tie" method, although I recommend using a piece of insulated solid wire (#12 or #14 will work fine.)

The wire, with a small "J" bent at the end, gets shoved down the plug 'ole and hooked under the head of the open valve, into the port:


("piston's eye" view from inside combustion chamber)

Then when the cam rotates away, the valve can't close all the way:




Which means the shim now has enough clearance to be removed; however, a problem arises: The bucket will invariably want to lift up with the shim, as they're often quite well stuck in there:




Which requires holding down the bucket while you pop the shim out:



NOW WHO'S GONNA PLUCK THE SHIM OUT? You're using two hands already...

This is another reason I recommend use of the tool, once three hands are involved the chance of a shim getting loose and ending up where it ought not increase exponentially.

Further, I don't like probing about in my combustion chamber and risking breaking loose chunks of carbon, or disturbing the nice even carbon "cushion" each valve sits on, which is why I use the tool.

If those things aren't something you feel you need to worry about, or don't have/can't get ahold of the proper tool, then at least you can see why I say to use a piece of wire rather than a Zip-Tie.

It makes it much easier to decide once you understand exactly how each method works.

Hope this helps, and as always, let me know if anything needs to be clarified or you'd like another picture of something I missed.

 

BigFitz, you couldn't be clearer than this. Now I finally understood what this is all about. "The tool" seems a clever, no-nonsense method.
A big thank you, and wishes of a merry christmas and a happy new year, with all the holiday beers you are entitled to!
Aharon, from the land of Hannukah, already on year 5.767!

 

Thanks fitz, this helped!

 

Hey thanks you Mr. Fitz. On your original post i didn't clearly understand about the notch on the buckets edge (even though it was photographed). Now with this posting i totally see and understand the notch and it's significance to rotate it for the tool to fit. Thank you! One day i will want to adjust my cycle's valves among other things. I always feared the shim and bucket until now! Perfect illustrations!

 

i used big fitz wire method, i used a coat hanger, small screw driver and a hemostat it worked great, with this method you dont have to worry about turning the motor the wrong direction and breaking the head!
thanks fitz

 

I like the insulated wire method as well. Super fast and easy. For shim removal I pop it out with a screwdriver but use a small J shapped piece of coat hanger wire under the backside of the cam to just push the shim forward and out. With just a little practice you should be able to pull, measure/record, replace and move to the next lobe in about 3 minutes.

 

This helped me alot to get ready for this job! Ha
Here is a link for that tool too. Dunno if you posted it anywhere else i just found this one. http://motionpro.com/motorcycle/partno/08-0020

 

One thing I hadn't thought of before the other day when I was talking to my machinist, was that with just jamming an ole piece of wire in the hole and under the valve was possible valve stem damage. He freaked when I told him how I did it. Thought that was a terrible idea, because the valve is only being held on one side. It could bend the valve. I have only used this method on my bikes and had no damage occur, but thought it might be worth sharing. Before my next valve check, I will be getting the tool.

 

It's not gonna bend the valve, or damage the valve guide.

What it CAN do, is crack a dried out valve stem seal that WAS working fine until side-loaded and cracked; or disturb the delicate carbon "cushion" on the valve and seat that helps it seal and cool.

If it bends a valve, then you needed a new valve, honest.

 

Well, I didn't know. I knew he didn't know because he has never done an xj motor. Thought maybe it was a useful thing to cover.

 

Has nothing to do with it being an XJ motor. ANY valve won't bend because you held it open with a piece of wire; nor will you damage a valve guide. They're simply a bit tougher than that, honest. Valve stem seals on the other hand, are fragile especially when 30 years old. Quite often they still work fine until somebody jams the valve stem sideways and splits them.

Somebody was yanking your chain, or didn't explain properly.

 

He thought that they were really small, he is genuine. I don't think he does many import stuff cars or bikes, of small displacement. He does a lot of tractors and big displacement hot rod engines. I think it must have been a misundertanding.

 

Well explained Fitz! Very nice.

 

If .. "ANY valve won't bend because you held it open with a piece of wire; nor will you damage a valve guide." Then how can.. "Valve stem seals ... when 30 years old work fine until somebody jams the valve stem sideways and splits them." It just don't seem logical in relation to the zip tie / wire method for changing shims.

 

It makes perfect sense.

The valve and valve guide are metal, and the side-loading from the zip tie or hunk of wire is not enough to bend or damage them.

However, the valve does have a small amount of side-to-side play in the guide. The seal isn't metal; it was rubber or viton or whatever once. Before it got baked a bit stiff. Jamming the valve sideways against the stiffened but still functioning seal can split it or deflect it enough to compromise it.

 

Re: AIRHEAD VALVE ADJUSTMENT Part 2: The Tool vs. ZipTie -w/

Just buy the tool, it is a real life saver. I recently adjusted the valves on my '81 650LH (now waiting on replacement shims), and using the tool was a breeze. The problem I had at first was I didn't THINK the tool was working because of the tight clearances and the fact that I didn't have proper tools to pluck the shims out. After reviewing bigfitz52's guides over and over, I finally gave it another go and the first time I put the tool in on each of the valves it worked like a charm. Make sure the notch is pointing AWAY from the tool, that's where you're going to pluck it out with a SMALL (non-magnetic of course) flat blade screwdriver, and a pair of hemostats (I got 2 pair on amazon for $4). I couldn't believe I had been messing this up for about a week trying to figure the tool out. The valve bucket will come almost the whole way to the top, but you have plenty of clearance between the shim and the cam lobe (because of this tool) it pops out pretty easy. And I didn't have to worry about shoving wires down the valves! Thanks a bunch bigfitz52! I couldn't do half the work I've done without your help!

 

Using 12/2 wire, rather than a single wire (as depicted) works well for me.

I don't think actual zip-ties should be used, as someone on this site had one "scissor off" , which would never happen to a piece of household wire.
(maybe defective, Made in China plastic)

 

using the "zip tie" or in my case twisted wire method I found it helpful to have someone else turn the wrench while working on 3 and 4 so I could hold the wire in place while the cams were rotated.

 

wonder why there's no mention of a degree wheel in these write-ups?

 

I recommend the tool, BUT, you will probably need to bore the holes out bigger on the tool. I found that out on my 83 550 SECA. Several were not even close to lining up with the tool and I almost gave up but had to do something. I got a vise and a drill and a chainsaw file, put the file in the drill and bored out both holes on the tool and part of the inner crevise. It then worked perfectly square on all 8.