schwager@uiucdcs.CS.UIUC.EDU (03/12/86)
. Anybody have experience working on valves that use shims? I'm thinking of getting a Kawasaki KZ750 and the valve adjustment on those uses shims. But I don't want to have to bring it in to a dealership every 3000 or 6000 miles and pay them exorbitant amounts of money for a little work. So can the average joe do it? If I have to keep $20 of spare shims around, no big deal. I figure I'll make up the price after just a couple of tune ups by saving on labor. What's the straight scoop? Thanks for the help, as always! -mike schwager -- {ihnp4,convex,pur-ee}!uiucdcs!schwager schwager%uiuc@csnet-relay.arpa University of Illinois, Dept. of Computer Science
jamitche@uok.UUCP (03/17/86)
Can't answer for Kawasaki but I'm real familiar with Honda shims (I used to own a '81 CB900F)(before some CAR driver totalled it for me) and yes, shims are no big deal, just a pain. Firstly, you don't know what shims you'll need till you've got the old ones out.(oh yeah, measure the valve/shim clearance beforehand, in the method your manual says).The shim'll probably be numbered somewhere. If not, you'll have to take a micrometer to it. (don't be scared, a cheap mic costs $8.00 at a hardware store). You'll probably also need SPECIAL TOOLS to get to these shims. If they're like honda's, you really do need the special tools, too. Here's a hint, make a map. Measure all the valves, take 'em all out, record their codes or thicknesses on the map. Then go down to the dealer. Keep the map. Next time you do this, you can see how much they've worn.
animal@ihlpa.UUCP (D. Starr) (03/17/86)
> > . > Anybody have experience working on valves that use shims? I'm thinking > of getting a Kawasaki KZ750 and the valve adjustment on those uses > shims. But I don't want to have to bring it in to a dealership every > 3000 or 6000 miles and pay them exorbitant amounts of money for a > little work. So can the average joe do it? If I have to keep $20 > of spare shims around, no big deal. I figure I'll make up the price > after just a couple of tune ups by saving on labor. What's the straight > scoop? Thanks for the help, as always! Checking the valves is not all that difficult. I'm not totally familiar with the KZ750 top end, but if it's like either the KZ900 I used to ride or the KZ650 I used to maintain for someone else, it's just time-consuming. You have to remove the gas tank (easy) and cam cover (many bolts but easy) and gasket (difficult, but you only do it once--then you glue the new gasket to the cover with weatherstrip cement and put silicone seal (easily separated next time) on the other side) to get to the valves. Then you just spin the engine around (with the kickstarter or that big nut on the crankshaft) and check the clearances when the valves are fully closed. The odds are that once you get out of initial break-in (say, 5000 miles) the clearances will be fine. These shim-type arrangements wear very slowly, and I know lots of people who go 20000 miles before needing an adjustment. So you may decide it's best at this point to check them yourself and go to the dealer for adjustments if you find them off. If you decide to do the adjustment yourself, you'll probably have to remove the camshafts (eight bolts each, and you need a torque wrench to reinstall). There's a chance that the shims will be on top of the lifters, in which case you can use a special tool to remove them without pulling the cams (is this a 750 4-cylinder or the very non-current twin?), but I wouldn't bet on it. The camshaft R&R's not all that difficult really, but there is a bit of work needed to re-establish valve timing when you put them in (line up crank at THIS mark, pull chain tight, line up one camshaft HERE and bolt it down, count so many links on the cam chain, line that up with THAT tooth on the other cam, bolt it down and torque everything down in sequence). By all means get the FACTORY service manual for torque values, clearances and timing marks. In my experience with Kawasaki fours, the check takes about two hours the first time and 45 minutes once you get the hang of it. The adjustment takes about half an hour more, not counting the trip to the dealer for shims (and the trip to the other dealer when the first dealer you go to doesn't have the one you need). Add more time to this estimate if you've got a lot of fiberglass junk surrouding the engine.
mazlack@ernie.berkeley.edu (Lawrence J. Mazlack) (03/21/86)
>> Anybody have experience working on valves that use shims? I'm thinking >> of getting a Kawasaki KZ750 and the valve adjustment on those uses >> shims. But I don't want to have to bring it in to a dealership every >> 3000 or 6000 miles and pay them exorbitant amounts of money for a >> little work. So can the average joe do it? If I have to keep $20 >> of spare shims around, no big deal. I figure I'll make up the price >> after just a couple of tune ups by saving on labor. What's the straight >> scoop? Thanks for the help, as always! > >Checking the valves is not all that difficult. I'm not totally familiar with > ... >If you decide to do the adjustment yourself, you'll probably have to remove >the camshafts (eight bolts each, and you need a torque wrench to reinstall). > ... I used to work on a shim adjustment engine and it is a pain. Granted, CHECKING to see if the tolerance is not too bad, once you take off enough stuff to get at it - but, the adjustment process usually requires a fair amount of knowledge, skill, and time. Also, you might need special tools. It is easier to get a bike that doesn't use them. Larry Mazlack mazlack@ernie.berkeley.edu
struve@calma.UUCP (Dimetry Struve) (03/22/86)
I think the Kawasaki 750 (wasn't that the bike in the original article) uses shims under the cam follower. This means the cams have to be removed to replace the shims. This is more time-consuming than difficult. I was very reluctant to try adjusting the valves on my CB900F, and had the dealer do it a few times. The Honda has the shims on top of the tappets, and they can be pried out with a screwdriver. When I finally decided to try the job myself, I found that it's easier to check and set the clearances than it is to get the tank, valve cover, etc. off to reach the cams. I also learned that the last time the dealer had done it, they had screwed up. Needless to say, I'll never trust them again. Incidentally, my bike has required about four valves to be adjusted in almost 50k miles. The Kawasaki, with the shims not in direct contact with the cam should last forever.
schwager@uiucdcs.CS.UIUC.EDU (03/24/86)
. Thanks to all who responded to my shim question! It didn't sound too scary, so I went and bought the KZ750. Once again, thanks much!! -mike schwager -- {ihnp4,convex,pur-ee}!uiucdcs!schwager schwager%uiuc@csnet-relay.arpa University of Illinois, Dept. of Computer Science
john@pbpra.UUCP (John D. Carmichael) (03/25/86)
In article <8800034@uiucdcs> schwager@uiucdcs.CS.UIUC.EDU writes: > >. >Anybody have experience working on valves that use shims? I'm thinking >of getting a Kawasaki KZ750 and the valve adjustment on those uses >shims. I got fed up with dealer service on my Yamaha FJ1100 too. Expensive and shoddy for the most part. I decided to adjust the valves myself, although I'd never done it before. The toughest part (on my FJ) is getting all the little pieces off so you can get to the valve covers. The tank is also a bear (next time I'll make sure it's empty...it weighs a ton). You should have the mechanics manual on your bike, as it will tell you where to position the crank to measure the valve clearance and you need the lookup chart for the shim sizes. Tools/supplies required: screw driver, feeler guage, assorted wrenches, special tool to hold down valves (see your dealer, cost ~$16), magnetic probe to grab the shims, mechanics manual. You may also need a new valve cover gasket (~$19 on my FJ, aayeeee!). Shims at ~$4.00 (buy these last). Gasket sealer to keep oil from leaking. On my FJ there are 16 of the little mothers, but note that the shims for exhaust and intake are identical (they come in various sizes however). For the most part, these shims do not wear out. The dealer even offered to take my old ones in exchange for the new sizes I needed, but I didn't have time to do the job in one day. You measure the present valve clearance (jot down the present clearance , and if it's out of spec, you take out the shim. There is a trick to taking out the shim that my manual didn't tell me. Before you tighten the special tool to hold down the valves, you rotate the shim and the gizmo it's seated in until a notch about 4mm wide by 2 mm deep is visible. Use a screw driver to rotate this (the cam lobe should not be contacting the shim, or it will be difficult to rotate). It is IMPORTANT to have this notch in position (as I found out), because otherwise it is virtually impossible to pry the shim out! Once you have the shim out you look at the number on the bottom of the shim (states the thickness), and look in a chart in your mechanics manual. This chart will then tell you the size of the shim that should go in there. Do not rotate the cam shaft lobes onto the valves unless a shim is present. From the factory, my FJ had several different size shims in it, Since some of the shims that were the wrong size at one valve location were also the right size for a different valve, I was able to swap them around and avoid buying new ones. This is why you measure everything first and then go buy the shims you need. It might be easier to have a few extra at the start, since you can't take them all out and rotate the camshaft. Once you've got the new shims in, check the clearances again. Occasionally, you'll have to get a slightly larger or smaller shim than you originally estimated. Save any left over shims for next time. When replacing the valve cover, I recommend some gasket sealer on the rubber seals surrounding the mounting bolts. This is where most of the oil leaks from. The actual valve cover doesn't leak perceptibly. The gasket should only have gasket sealer on one side (the side next to the cover). I was able to reuse my gasket, so I'm stuck with an extra one...oh well. The end result: one weekend (1-3 hours for you experts), one $16 tool, and two $4 shims later and everything works great! I had the dealer do the adustment at 600 miles ($105 on my FJ), but after that it's cheaper and more satisfying to do most work myself. I do better work than they do anyway! John D. Carmichael, PacBell dual!ptsfa!pbmnms!john or dual!ptsfa!pbpra!john voice: (415)-823-2822