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Head Work - Valve Seats
- KZ1000P1995
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25 Oct 2017 11:03 #773713
by KZ1000P1995
Head Work - Valve Seats was created by KZ1000P1995
Hello All,
Valuable LESSON LEARNED. Do not trust an automobile machine shop with your motorcycle head!
With my original head I asked for them to lightly "touch" the valve seats to give them a clean edge. I explained (to deaf ears) how it was a shim/bucket design and that there wasn't much room to remove. Well, they ground them down so low that I could no longer shim the valves to fit. Even after buying the smallest shims I could find and then valve tipping and modifying/ruining NEW valves to try and make it work. Only option for this head now is to pay $800 to have a motorcycle shop install new valve seats.
Second experience: the SAME! I took this ebay head to a different shop who assured me that they are not "idiots" and would never do that type of work. Well, after dropping my newly received and cleaned Ebay head to have the valve seats LIGHTLY TOUCHED, he did the exact same thing. I first banged my head against the wall, then cried, then exploded . . . he didn't really care
Third experience: I bought a Craigslist parts bike for $400 and simply lapped the valve seats myself. Not perfect, but GOOD ENOUGH and she runs well with 150psi all around. Lesson: DO NOT TRUST your local machine shop with a motorcycle head! Lesson learned.
BTW, I have 2 extra heads that need new valve seats if anyone is interested.
Valuable LESSON LEARNED. Do not trust an automobile machine shop with your motorcycle head!
With my original head I asked for them to lightly "touch" the valve seats to give them a clean edge. I explained (to deaf ears) how it was a shim/bucket design and that there wasn't much room to remove. Well, they ground them down so low that I could no longer shim the valves to fit. Even after buying the smallest shims I could find and then valve tipping and modifying/ruining NEW valves to try and make it work. Only option for this head now is to pay $800 to have a motorcycle shop install new valve seats.
Second experience: the SAME! I took this ebay head to a different shop who assured me that they are not "idiots" and would never do that type of work. Well, after dropping my newly received and cleaned Ebay head to have the valve seats LIGHTLY TOUCHED, he did the exact same thing. I first banged my head against the wall, then cried, then exploded . . . he didn't really care
Third experience: I bought a Craigslist parts bike for $400 and simply lapped the valve seats myself. Not perfect, but GOOD ENOUGH and she runs well with 150psi all around. Lesson: DO NOT TRUST your local machine shop with a motorcycle head! Lesson learned.
BTW, I have 2 extra heads that need new valve seats if anyone is interested.
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- Nessism
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25 Oct 2017 13:41 #773719
by Nessism
Replied by Nessism on topic Head Work - Valve Seats
That sucks man. I don't trust most shops to do that sort of work. Better to pony up and send the head to APE or similar quality shop. Or, get some Neway cutters and do the work yourself! That's what I did anyway. I did trust a shop to clean up the valves using a centerless grinder. Hard to mess up with one of those.
P1020063
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nessism
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P1020104
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nessism
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- Scirocco
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25 Oct 2017 14:42 - 25 Oct 2017 14:43 #773724
by Scirocco
My 1975 Z 1 B 900 Project
www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode
Replied by Scirocco on topic Head Work - Valve Seats
Yes this sucks. A waste of money and a lesson learned twice.
I bought a set of Neway cutters 20 years ago and do all head work by my self.
I bought a set of Neway cutters 20 years ago and do all head work by my self.
My 1975 Z 1 B 900 Project
www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode
Last edit: 25 Oct 2017 14:43 by Scirocco.
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- SWest
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- 10 22 2014
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25 Oct 2017 15:19 #773727
by SWest
Replied by SWest on topic Head Work - Valve Seats
I want some.:ohmy:
Steve
Steve
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- Scirocco
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25 Oct 2017 15:42 #773729
by Scirocco
My 1975 Z 1 B 900 Project
www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode
Replied by Scirocco on topic Head Work - Valve Seats
Valve seat cutters or patches?
My 1975 Z 1 B 900 Project
www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode
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25 Oct 2017 15:50 #773730
by SWest
Replied by SWest on topic Head Work - Valve Seats
Got the patches thanks.
Steve
Steve
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- les holt
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26 Oct 2017 00:55 - 26 Oct 2017 01:00 #773746
by les holt
Replied by les holt on topic Head Work - Valve Seats
New valve seats aren't necessary, it's not uncommon to have the valves tipped, meaning to have the stem ground back to a set height. APE sells a gauge to measure the stem heights so you can adjust them to tune with standard shims.
Les Holt
Les Holt
Last edit: 26 Oct 2017 01:00 by les holt.
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- Nessism
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26 Oct 2017 07:31 - 26 Oct 2017 10:04 #773760
by Nessism
Replied by Nessism on topic Head Work - Valve Seats
Jay from APE wrote in an older thread that when the valves are really sunk, and the valve stems trimmed somewhat drastically to get the valve back to the proper height, then it may also be necessary to grind the valve keepers otherwise they will stick up above the valve stem after the spring is installed. He said that Police bikes sometimes get this sort of work done to get more life out of the parts.
Last edit: 26 Oct 2017 10:04 by Nessism.
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- les holt
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26 Oct 2017 07:41 #773761
by les holt
Replied by les holt on topic Head Work - Valve Seats
Yeah, I forgot to add the part about checking the keepers! I've only had 1 head that I had to do that too!
Scirocco, I have been using Neways for years and they do a good job, I found using a cordless drill on low gave me better results that the T-handle. You're able to keep constant pressure and you can control the speed well.
Les
Scirocco, I have been using Neways for years and they do a good job, I found using a cordless drill on low gave me better results that the T-handle. You're able to keep constant pressure and you can control the speed well.
Les
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26 Oct 2017 08:15 - 26 Oct 2017 13:51 #773762
by Scirocco
My 1975 Z 1 B 900 Project
www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode
Replied by Scirocco on topic Head Work - Valve Seats
I do the hand job with the T-handle, because only 2-3 turns max. are needed to get a smooth
seat surface and to correct the angles for the seat. The Tungsten carbide blades are very sharp and bite
easily into surface. I grid no more as necessary for a later valve job.
EDIT: I am searching for an Gizmatic 3 valve tool. It has a 2 sided valve cutter with 45 & 30 degree fixed angles.
seat surface and to correct the angles for the seat. The Tungsten carbide blades are very sharp and bite
easily into surface. I grid no more as necessary for a later valve job.
EDIT: I am searching for an Gizmatic 3 valve tool. It has a 2 sided valve cutter with 45 & 30 degree fixed angles.
My 1975 Z 1 B 900 Project
www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode
Last edit: 26 Oct 2017 13:51 by Scirocco.
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- 531blackbanshee
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26 Oct 2017 09:04 - 26 Oct 2017 09:05 #773764
by 531blackbanshee
skiatook,oklahoma 1980 z1r,1978 kz 1000 z1r x 3,
1976 kz 900 x 3
i make what i can,and save the rest!
billybiltit.blogspot.com/
www.kzrider.com/forum/5-chassis/325862-triple-tree-custom-work
kzrider.com/forum/5-chassis/294594-frame-bracing?limitstart=0
Replied by 531blackbanshee on topic Head Work - Valve Seats
skiatook,oklahoma 1980 z1r,1978 kz 1000 z1r x 3,
1976 kz 900 x 3
i make what i can,and save the rest!
billybiltit.blogspot.com/
www.kzrider.com/forum/5-chassis/325862-triple-tree-custom-work
kzrider.com/forum/5-chassis/294594-frame-bracing?limitstart=0
Last edit: 26 Oct 2017 09:05 by 531blackbanshee.
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- Daftrusty
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26 Oct 2017 15:22 #773786
by Daftrusty
1990 zr550
kz750e
650/750 6-speed Transmission Swap
Replied by Daftrusty on topic Head Work - Valve Seats
I have a zr550 head that had exhaust seats so pitted that they needed recut. So I took it to the local independent motorcycle shop (support local businesses and all) and he used a Nu-Way hand cutter to do them. And he cut them so off center that when I lapped the valves and did a gasoline leak test, none of the combustion chambers could hold gas for 30 seconds. The gas literally poured out of the valves in seconds.
So I took it to a automotive shop and he recut the seats on a Serdi (really deep to get past the off center portion) and then after careful measuring, I had him tip the valves and cut down the valve retainers. Not one issue since.
So I took it to a automotive shop and he recut the seats on a Serdi (really deep to get past the off center portion) and then after careful measuring, I had him tip the valves and cut down the valve retainers. Not one issue since.
1990 zr550
kz750e
650/750 6-speed Transmission Swap
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