shims and things

[Anonymous]

Hi all, my problem is this, the Clymer manual says clearance for the shims is between .03 and .08 mm. On most I cannot get the .03 in. and others .05, do I need to have each cylinder set up on TDC or just do them one at a time. The manual is not clear on this it just says to have the cam lobe perpendicular to the head. now to complicate things I did a compression test, 1 ,2 and 4 all read 150 psi and no 3 reads 120 psi (this not good! I know) so as I need to balance no 2 to no 3 and then the outer two is this going to make a huge error. also the Clymer manual says to have the levels for 2 and 3 cylinders together and 1 and 4 slightly lower when using the Suzuki balancing tool, do I follow this or have them all even, I am using a motion pro mercury balancer. Any suggestions will be greatly appreciated (and will aid in the restoration of my sanity) cheers

George. J

[saaz]

Hi Tassie, Canberra here

The manual is correct in that the cam lobe should point vertically when being measured. Usually two lobes will be in this position at any one time. If you cannot get the .03 guage in the clearance is too tight, which can lead to burnt valves and low compression. Is the low compression cylinder where the clearances are tight?

120 is on the low side, but I would check all the valves clearances and get them right first.

[KEITH KRAUSE]

I use a Motion Pro mercury vacuum tool also. I get good results making them nearly level straight across. At least get them all within the same two lines. If they are more than 2 cm difference you will experience mixture problems. I insist on getting them within 1 cm of each other at 3,500 rpm. Make sure you have a couple of fans on the motor.
To do my '79 1000 tappet clearances, my factory manual says check the exhausts cams #1 and 2 first, the top of cam lobe #1 will be pointing at 9:00, the top of cam lobe #2 will be at 12:00. Turn the crank clockwise 180 degrees and check the intake cams #1 and #2, the top of #1 cam lobe will be at 12:00 and the top of cam lobe #2 will be at 3:00. Turn the crank another 180 degrees and check the exhaust cams #3 and #4, the top of cam lobe #4 will be at 3:00 and the top of cam lobe #3 will be at 12:00. Turn the crank 180 degrees and check the intake cams 3# and #4, the top of #4 intake will be at 12:00 and the top of #3 will be at 9:00.
The shims can vary in thickness even if they say they are the same. A shim with an "x" after the number is a "fat" shim. Make sure the motor is STONE COLD and always double check your adjustments by going through the check cycle again. Don't use Kawasaki shims by mistake, they are only 29mm measured across. The Suzuki's are 29.5 mm across.

[saaz]

I have quite a few spare shims if you need them. I always measure the used ones with a micrometer to pick the best one for the clearance. They can vary a bit. My cams are aftermarket so i run .15 to .2mm clearances...so I have a few standard shims left! The standard cams have noise deadening ramps so have tighter clearances.

[Anonymous]

thanks guys I bought a new set of feeler gauges and this what i found

no 1 in .03 ex 0.10
no 2 in .08 ex .04
no 3 in .04 ex .03
no 4 in .04 ex .13

1 and 4 exughst are a bit of a worry but are within tolarance.

I have put just over 21000 km on the bike in 2 years so she now has over 121000 km so she might be about ready for a big birthday.
saaz I'll let you know if I need those shims mate.
and keith thaks again.I will most likely be posting questions.
cheers

I ride as if I am invisable, Tin top drivers are blind! :twisted:

[KEITH KRAUSE]

Georgej, according to your measurements, your exhaust cams #1 and #4 are NOT within spec. The range is .03-.08mm. You need the next size thicker shim on each. Actually, the #4 exhaust may need 2 sizes thicker, but most likely just 1 size thicker. It will depend on if you have some "fat" or standard shims to use. If you get a .03 mm feeler in there but it's tight and you have to wiggle it to get it in, I personally would rather set it to .08mm. Borderline too tight is worse than borderline too loose. The shims are commonly not exactly what they are stamped, so a little experimenting has to go on.

[Anonymous]

Borderline too tight is worse than borderline too loose.

Hear, hear. I always set clearances at the loose edge of the specs. Clearances close up over time, they don't loosen, so starting on the loose side is always preferable. As noted earlier, tight clearances can cause you to burn an exhaust valve while the worst that will happen with loose clearances is slightly less power (from less valve lift), but I doubt it could be measured.

Mark

[Anonymous]

[quote]1 and 4 exughst are a bit of a worry but are within tolarance.


Hi I just read what I wrote, change that to 1 and 4 exughst are a bit of a worry but the others are within tolarance.