To grind or not to grind... Valve stem tips

  • missionkz
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To grind or not to grind... Valve stem tips

25 May 2015 15:16
#673690
Now I need two or three 225s and maybe a skinny 230... or take the valves out and have the tips ground between ..001" and .004" so I can use different combs of shim thickness to make it all up.

Some of the measured lash gaps at .002", some at .006" and one is a fat .007" ... all with using the hand full of #215 shims I have.
So, I'm thinking two 225s to close the big gaps up.
But .002" feels a little tight to me. I'd rather they were all .003" but maybe that's too anal...

I have two others at .004" with 235s ... not sure if I should take a chance on these with 240s and also grind the tips a .001"- .0015".

Been very careful over the many years of valve lash adjustments, with my shim gaps never under .002" and some as much as .003"-.004".
I'd prefer a tad loose then tight, but, .004" to .007" seems too loose
The only way to get in between those standard shim, thicknesses, where the sizes change .00197" (.002") up and down from number to number, is to remove all the valves and have the stem tips ground a thousands of an inch....???
What is the general consensus?
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado

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Re: To grind or not to grind... Valve stem tips

25 May 2015 17:55
#673712
missionkz wrote: I'd prefer a tad loose then tight, but, .004" to .007" seems too loose
On my 750 twin, I run them .003 - .005". The original FSM said .002 - .004" but later many places said Kawi had opened it up to .002 - .006".
1979 KZ-750 Twin

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Re: To grind or not to grind... Valve stem tips

25 May 2015 18:07
#673715
Does anyone know definitively if the 29mm shims can be ground .001" or so?
I've read two or three, totally different, answers to these shims being hardened all the way through or just a few thou's case hardened.
I've also heard of a few guys doing it with zero consequence.
I have access to surface grinder and a large handful of "close but no cigar" shims.... I don't know what to believe.
I could trim a couple of my 235's down to 230 and two of my 230's down to 225 with only a .001" grind from each side. ETC>>>>
I read somewhere that they are slightly doomed too.... my micrometer does not back that up.
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado

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Re: To grind or not to grind... Valve stem tips

25 May 2015 18:16
#673719
I would not grind the shims at all. There has been a considerable amount written documenting the reasons you should not, and I am convinced it is a mistake to do so. Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)

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Re: To grind or not to grind... Valve stem tips

25 May 2015 18:19
#673720
I've also read you can grind off a couple thou from the stem button under the bucket.
Anyone??
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado

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Re: To grind or not to grind... Valve stem tips

25 May 2015 18:41
#673724
Yes. It is common to "tip"the valves after recutting the seats. There is a special tool for it.
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1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24

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Re: To grind or not to grind... Valve stem tips

25 May 2015 18:48 - 25 May 2015 18:57
#673726
Right but I was talking about the little button inside and under the shim bucket....
Probably dumb....


Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado

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Last edit: 25 May 2015 18:57 by missionkz.

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Re: To grind or not to grind... Valve stem tips

25 May 2015 18:49 - 25 May 2015 18:50
#673727
No eBay APP ID and/or Cert ID defined in Kunena configurationYes, you can grind the vave tip slightly -usually when the shim gets below the minimum available. I have a -0.10 and -0.15mm, not sure how far you can go under this.

I was going to offer you some free, i have a box of 60, just not in your shim over bucket size.

Is this nearly what you need? vendor claims z power uk have them in stock....good luck anyway.

1980 Gpz550 D1, 1981 GPz550 D1. 1982 GPz750R1. 1983 z1000R R2. all four aces
Last edit: 25 May 2015 18:50 by Tyrell Corp. Reason: speeling hic

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Re: To grind or not to grind... Valve stem tips

25 May 2015 18:59
#673731
Yes, the 29mm shims.... they run anywhere from $7 to $10 plus around $4-$6 shipping here in the States
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado

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Re: To grind or not to grind... Valve stem tips

25 May 2015 19:09
#673736
Sorry thought they were unavailable...surely the cost of a head gasket alone would be more than the cost of buying new shims?

Seems like a difficult way to solve an easy problem :unsure:
1980 Gpz550 D1, 1981 GPz550 D1. 1982 GPz750R1. 1983 z1000R R2. all four aces

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Re: To grind or not to grind... Valve stem tips

25 May 2015 19:24
#673741
Tipping the valves .010 is good. Tipping the valves and grinding the bucket "button", DISASTER. Think about it, the button keeps the lifter cup from hitting the valve spring retainer.
Steve

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Re: To grind or not to grind... Valve stem tips

25 May 2015 19:31 - 25 May 2015 19:31
#673744
missionkz wrote: Yes, the 29mm shims.... they run anywhere from $7 to $10 plus around $4-$6 shipping here in the States

Rather than risk messing up your engine trying to avoid buying shims that are over-priced I suggest you simply find shims that are more reasonably priced.

For example - Z1E sells the 29mm shims for $4.82 each (rather than the $7-$10 ones you found). Ed

www.z1enterprises.com/ListItems.aspx?keywords=12037-001
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
Last edit: 25 May 2015 19:31 by 650ed.

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