Valve adjustment - what are your experiences.

I have an '83 XJ550K Maxim, that I've owned since new. It has 24K miles on it. The valves, if I remember correctly, were adjusted last around 10-12K miles. The book says every 5-8k miles if I'm not mistaken.

I have done a lot of neglected maintenance this year, and the bike is running better than a long time. I've not however, opened up the valve cover and checked to see if it is in spec. I have a neighbor that agreed to help me do it in the spring if I purchase the supplies (gasket, grommets and shim kit). The closest Yamaha dealer is an hour away, and wanted $400-$500.

My question is what is everyone's experience on how far out of specs things really get after 12-15k miles without a valve adjustment for this, or similar bikes. It isn't that I don't plan to do it, I'm just curious how often people find that everything really is ok. (My m/c mechanic neighbor drove it and suspects it can't be too far out of spec as it is running and starting well).

Also, can anyone recommend an economical shim kit? I don't want to wait until it is open, then order the proper ones, etc. Once I get the valve cover off, I want to be ready with whatever shims I will need. Maybe a dumb question, but are their likely shims to have on hand, if I don't buy a full kit?

Have a good winter. My bike was put away to hibernate yesterday. Winter storm today.

 

1. Yes, you need to inspect the valves, and at 24k some will likely need to be adjusted.

2. Don't buy a shim kit. You will very likely only need a few, and can move some of the others around to bring everything back into clearance. Check clearances, pull the shims one at a time to note what' there (make a table in a logbook so you have it for reference the next tme), and the only buy the shims you absolutely need. Member Hogfiddles runs a shim pool so you can trade shims with him as well.

3. Inspect the gasket and valve bolt rubbers. If they are hard (if your valve cover leaks they are likely hard; if they are original they are likely hard) then order new ones from user Chacal. The gaskets on the YICS engines (yours is one) can be reused several times, and the bolt rubbers can be used until they no longer press the valve cover down on the gasket firmly. Do not over tighten the valve cover bolts. They are of a shouldered design and do not provide the clamping force to seal the valve cover; the rubbers do that job.

Rubbers.

 

Then replace the shim. Do not turn the engine without having a shim installed at every bucket.

Use a ratchet wrench to bring them snug then use a allen wrench to do the final torque.

Gary H.

 

It's cool worry about it in the spring but not too much. Que sera sera
I am just back from the pub howeber

 

Yup, do check them

 

hardest part was getting the shim out of the bucket. used small screw driver then a junk feller gauge.

get a metric set K-D tools 2274 Metric Feeler Gauge

any auto parts store can order it for you

no way of knowing what shims you will need untill you pull them out and measure them or read the size on the back side.

29mm shims chacal sells them and Hogfiddles has a shim pool

and instructions on how to do it
AIRHEAD VALVE ADJUSTMENT with Pics

 

Our point is...you can't know this until you pull the existing shims and it's not cost effective to order a kit of shims and only use a couple of them.

Gary H.

 

chacal sells them his are supposed to work better than others
or google moto tool 90890-01245-00 bikebandits has then about 15$

 

Shim tool is optional. Search BigFitz's thread about the zip tie method. Many swear by it!

 

or single strand 12 gauge house wire.

bigger the zip tie the better sometimes you have to fold it to double it up
sometimes it is easier to do if the exhaust is off for the exhaust valves. access to valves is easier.

 

Pictures in this link using the solid wire:

http://www.xjbikes.com/forums/threa...tment-part-2-the-tool-vs-ziptie-w-pics.29209/

The valves basically pound into the seats on the head over time which reduces clearance

Another debate that might be worth noting - does valve clearance get tighter or looser as the engine heats. I used to be in the camp of they got tighter, as the expansion of the cams, shims, rockers, etc on the top end would reduce clearance. I was corrected by what I now believe, that valve clearance gets bigger on a hot engine, as the majority of the heat in the combustion chamber causes the valve and head to expand more than the top end, which results in a larger measured gap when hot.

 

The entirely depends on what clearance you are measuring (stem to valve-opening device, or valve face to valve seat), and what mechanisim is being used to move the valves. With shim over bucket (like we have) the valve shim-to- cam clearances generally get tighter as the engine accumulates more hours. Rocker's tend to get looser as the tappet pounds on the valve stem top. Desmos tend to get looser as their tiny shims wear, but can also get tighter early on as the valves wear in. Ther are a host of other valve actuation devices, and they all have somewhat different wear characteristics.

 

The shim sits in the bucket. The bucket sits on top of a seat which hold the inner and outer valve springs in place. When the cam lobe compress the springs the tool hold the bucket down from the top. As such the zip tie holds the valve/compressed springs open from the bottom which keep the bucket down. In both examples the lobe is then rotated to allow for measuring clearance. See Rooster and k-moe's explanation for how they get tighter.

Gary H.

 

You can spend $15 to get " the tool", or spend $2 for a pack of zipties, or spend $0 for a scrap piece of copper wire.....

You can use the tool, and spend an hour trying to get it to work---- and then do it all over when you find out that the notch isn't lined up correctly........ The go to the next valve-----

While, in the meantime, I'll have all my valves check with the ziptie by the time you get you second one out.....

I have two of the tools and use neither of them.

There is NO reason at all to remove the exhaust.

 

zip tie goes through the plug ole, when you remove the plugs you can see the open valve, the zip tie slips between the valve head and the seat
stu

 

The zip tie like a said go through the spark plug hole I used to tips and it holds the valve wide open and also allows the bucket to be rotated as needed under the cam. If you use the tool the dual holds the bucket in place and you cannot rotate it you have to guess how to position the bucket so it rotates to the right place first.

 

the zip-tie has to be doubled (for more strength) and folded like an L to go in the spark plug hole AND get under the opened valve. I think it is well pictured in one of Bigfitz's tutorials.

 

The link that Rooster posted has pics of the 'non-tool' procedure being performed with an insulated heavy gauge wire instead of the zip tie.

 

Imo learn it the "long tooth" way. Learn to use the tool, zip tie method and thick wire technique then choose which YOU prefer. In addition you'll always know it can be done and trip out some of your friends at the same time when you do it without the tool.

Gary H.

 

There's tutorials out here, read up on it… You'll get it quick.

Heck, I figured it out without a tutorial… It's simple:

Push the valve down with the cam, stick the zip tie and a hold valve open. then rotate the cam out of the way. Do your valve shim and swap, rotate the cam back down, remove the zip tie....go onto the next one. And it really only takes about as much time as it took to read this......

Or maybe about as much time as it took to correct the typos.....