Valve Clearances - Opinions?

Hey Gang - I decided to get inside my motor again to check on the cam chain and valve clearances. I had a problem with my automatic cam chain adjuster back in the fall (thought it had snapped into place and started the motor-that'll teach me to make this adjustment with the stereo blasting Lynyrd Skynyrd!) and the chain jumped a couple of teeth bending an exhaust valve which was replaced.

The loose chain caused the idler gear to move a little so I replaced its shaft and this eliminated the sideways play. I've got a new chain adjuster spring coming in tomorrow to make sure the plunger extends fully.

Last night I measured the cam chain for wear and counting twenty links it came in at the serviceable length of 161.5 mm.

Tonight I pulled the coils and cam cover and came up with these measurements on the valves. My factory mechanic's manual calls for 0.08-0.18 mm.

I'd appreciate some opinions or recommendations of reshimming based on these feeler guage measurements.

Exhaust
1. 0.10 tight fit
2. 0.15 mm tight fit
3. 0.015 mm tight fit
4. 0.10 mm (probably could fit in an 0.11

Intake
5. 0.13 mm tight fit
6. 0.10 loose (probably could fit and 0.11 or 0.12)
7. 0.15 mm loose fit
8. 0.10 mm loose fit

Cheers-Colin Firth-Ontario Canada

Post edited by: reborn650, at: 2007/03/20 20:09

Shim for the upper end of given limits, which for your bike is .002" to .006" (sorry got to use imperial), so looking at what you got I would only change #3 exhaust shim as it is getting a bit tight....only about .001" clearance...the rest are OK

The clearances will only close up over time...

1045

1045 wrote:

Shim for the upper end of given limits, which for your bike is .002" to .006" (sorry got to use imperial), so looking at what you got I would only change #3 exhaust shim as it is getting a bit tight....only about .001" clearance...the rest are OK

The clearances will only close up over time...

1045

I agree, but I still say don't bother using goofy size feelers. Only use feelers in .002" (.5mm) increments.
This would give you.

Exhaust

1. 0.10mm (OK)

2. 0.15mm (OK)

3. 0 (go down 2 sizes on shim and recheck)

4. 0.10mm (OK)

Intake

5. 0.10mm (OK)

6. 0.10mm (OK)

7. 0.15mm (OK)

8. 0.10mm (OK)

Using only feelers in the increments of shim sizes makes calculation much simplified. I don't know if anyone understands this or not, maybe just a personal preference after 30 yrs of owning this type of engine. It does no good to measure more precise than .05mm because shims only come in .05mm increments. This may give you a little on the looser side of the shim increments doing it this way but much simpler and you really only need 4 feelers (.05mm, .10mm, .15mm, .20mm). Throw away the .051mm, .052mm whatever, just stay .05mm increment.

RonKZ650 wrote:

1045 wrote:

Shim for the upper end of given limits, which for your bike is .002" to .006" (sorry got to use imperial), so looking at what you got I would only change #3 exhaust shim as it is getting a bit tight....only about .001" clearance...the rest are OK

The clearances will only close up over time...

1045

I agree, but I still say don't bother using goofy size feelers. Only use feelers in .002" (.5mm) increments.
This would give you.

Exhaust

1. 0.10mm (OK)

2. 0.15mm (OK)

3. 0 (go down 2 sizes on shim and recheck)

4. 0.10mm (OK)

Intake

5. 0.10mm (OK)

6. 0.10mm (OK)

7. 0.15mm (OK)

8. 0.10mm (OK)

Using only feelers in the increments of shim sizes makes calculation much simplified. I don't know if anyone understands this or not, maybe just a personal preference after 30 yrs of owning this type of engine. It does no good to measure more precise than .05mm because shims only come in .05mm increments. This may give you a little on the looser side of the shim increments doing it this way but much simpler and you really only need 4 feelers (.05mm, .10mm, .15mm, .20mm). Throw away the .051mm, .052mm whatever, just stay .05mm increment.

I made a mistake on typing in the 3rd measurement on the exhaust. It should have read 0.15mm not 0.015

Cheers-Colin Firth - Ontario Canada

RonKZ650 wrote:
Using only feelers in the increments of shim sizes makes calculation much simplified. I don't know if anyone understands this or not, maybe just a personal preference after 30 yrs of owning this type of engine. It does no good to measure more precise than .05mm because shims only come in .05mm increments. This may give you a little on the looser side of the shim increments doing it this way but much simpler and you really only need 4 feelers (.05mm, .10mm, .15mm, .20mm). Throw away the .051mm, .052mm whatever, just stay .05mm increment.[/quote]

Now this is interesting !

I use metric feeler gauges because it is easier to understand which shim is needed. I also use more gauges than old650 uses but I like to know "partial" increments because I also will allow the clearances to be a tad larger than Kaw recommends. They recommend .05 to 1mm for the KZ1000 but I will go up to .127 clearance. I use .051mm, .064mm, .78mm, .102mm, .127mm feeler gauges. You also need to have a larger feeler gauge in the event you are trying to come down in clearance. This happens when you put a 2.00 shim in on a bike with unknown clearances and the original shims had less than .051mm clearance. I will also use the .152 and perhaps a couple larger feeler gauges. I like using metric gauges because I can have a good feel for which shims are needed and don't need to "convert". I do use another set of feeler gauges for spark plug gaps and these are SAE (inches). Actually this tool also has a bender for the electrode.

That's a good way to do it too George. Even doing it the way I said though generally you'll have a little more clearance than actually measured. For example lets say I'm shooting for a 0.10mm clearance. I insert a 0.10mm feeler and it fits, then I insert a 0.15mm feeler and it doesn't fit. What do I know? I know clearance is between 0.10 and 0.15mm. Do I know or care if it's 0.11, 0.12, 0.13, or 0.14? No. Do I care which of these figures it actually measures? No, because even if I did, shims only come in .05mm increments and changing a shim would put the clearance no longer between 0.10-0.15mm. If this makes any sense hopefully.

Sure does Ron but if I have a clearance that is actually .127mm, I know that I can go down one shim size to get it within spec... or better put, if I have a shim that is .178mm I can go down one size and get it within my own personal upper end tolerance (.127mm). If I used fewer gauges, I wouldn't be real sure if I needed to take it down one or two shim sizes, if that makes sense. I have found that the valves get noisy at .152mm and start to nick up at .178mm just a tad and are real noisy. I am guessing that .152 isn't going to do any harm but that is just a guess and I get a tad nervous with all that clatter... hehe

Well after all that, your good to go reborn650...

1045

Well after all that, your good to go reborn650...

1045