No Valve clearance

As usual I have searched but I did not find an answer this time. (Although WG’S Shim article was EXCELLENT and the info will be used). My problem is that I have NO clearance on 4 of my valves now that I have reassembled the head. I just need to know where to start to try and get a handle on re-shimming. If I really have to I will take the head off the engine again but that would make me unhappy.(I’m already 2 months behind on the project.) The valves with no clearance all have 260 shims. 2 valves have 235 shims and have clearance. Would moving the smaller shims around possibly help? That seems like a good idea but it also seems too easy!

find the shim that is the smallest and use it in all of the valves, this will tell you how much you need to shim the valves up

Thanks I'll try that tonight.

This is why it is so important to bench shim any head that has had a valve job done, before installing it on the motor.

200 is the thinnest shim for that head. get some of those and see if you have any clearance with those. If you do, then you can do the math and see what you need. I don't like seeing shims under 220 on a new valve job as they will tighten up after the initial run in, then you will be at the bottom of the shim range.

Jay

I find that if you measure the valve stem length with the head disassembled, you can pretty accurately come up with the correct assembled shim size. There is a chart in the Kaw KZ1000 Factory Service Manual. Also, have a 200 shim on hand for checking specific clearance on assembled heads... it is too tedious to swap this shim and that to gain sufficient clearance to measure the thing. If the valve stem lengths are excessive, and the seats still in OK shape, remove the valves and have them ground for length (keep them within spec). Short valve stems will give you more clearance and grinding is cheaper than new seats and a valve job.

Thanks for the answer guys. Stupid question time George where do i measure the valve stem? If I use a caliper I could get a measure from the centre of the of the valve(?)to the end of the stem. that actually makes sense now that I've typed it. I was able to get a 2.25 shim(all they had) I go through the tedium of putting it under one bucket and see if that gets me anywhere. I pull everything backa part if it does not.

Thanks again for your very valuble assistance.

If you get a good valve job by a decent mechanic you should only have to go down 2-3 shim sizes. This is what I was told anyway by the only mechanic I ever had do a correctly done valve job, and he was right on the money. Conversely under warranty I had a valve job on a 1 yr old 82 GPZ1100 and the idiots put 200 shims in all 8 valves and thought that "good enough". No clearance even with 200 shims after those morons. Valve job only as good as the guy who did it. You'll have to swap in those smaller shims and hope you regain enough clearance to measure and go from there.

Whoever did the valve work should have had the stem lengths set so the head would shim correctly.

We make valve height gages for the KZ/GPZ (900 thru 1100) motors in all of the popular base circle sizes.

Jay

I see what the esential problem is here.

I'm an idiot:blush:

There was no valve job done. I checked everything out and it did not need a full valve job just new seals and lapping.

Or so i convinced myself.

FYI i really don't want to invest in this bike. I like the bike but it is only a 550. It has severe limits on what i can do with it . I really just wanted to take it apart and put it back together a little better than I started. A learning experiance if you will.

Some thing s have gone REALY well. The gas tank already looks awesome and it's just primered and the other cosmetic stuff is good too. The bottem end is all good as well. It's just the head that's a problem.( mine or the bikes)

I will follow some of your good advice and see how it goes. I am time time challanged over the next two weeks so it will be a PITA to get to the bike but i'll post results once i do.

Thanks again for your help.

The most important measurement you can do with the head disassembled is measure stem height. To do this remove the valve stem oil seals and the round disks at the bottom of the valve well. Put the valve in the guide where the stem is exposed in the well. On your caliper, there should be a "tail" that sticks out at the bottom when you open the two arms. This tail is used to measure length. You put it down into the well till it touches the bottom and measure to the top of the valve stem (where they are ground for length). The measure on a KZ900/1000 is between 37mm and 38mm (I don't recall exactly) but if you find you exceed this length, you can get the valve stem ends ground a bit by a machine shop. It isn't expensive... only so much can be ground so get a manual and familiarize yourself with the amount that can be ground off a stem. A KZ1000 manual has a chart that tells you which shim to fit given a specific measured stem length. I suspect a 550 manual will as well. Once you have the engine together, it is a great idea to once again measure and adjust valve clearances.

Thanks WG I'll do that.

Update. I followed the suggestions given and now have shim sizes to buy. I was JUST out with the shims I had on the valves that were too tight. I am setting everything to the loose side of things so it can tighten up .

One question. The buckets should all be the same correct? I used a mic to measure the thickness and was suprized that they were quite different.

Thanks again for the help.