Author Topic: 750 K1 project  (Read 2532 times)

Offline Trigger

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Re: 750 K1 project
« Reply #30 on: April 15, 2018, 12:21:12 PM »
That looks better. The skirts are very tight on a Honda.
Is there any lip at the top of the bores, pics please  ;)

Offline Crispy

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Re: 750 K1 project
« Reply #31 on: April 15, 2018, 01:13:17 PM »
That looks better. The skirts are very tight on a Honda.
Is there any lip at the top of the bores, pics please  ;)

Yes I can feel a lip.
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Offline Trigger

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Re: 750 K1 project
« Reply #32 on: April 15, 2018, 01:25:05 PM »
OK, they need to be honed out until the lip is visible no more. Then you can get a true measurement  ;)
I know what all the books say to the max spec but, when this engine was new, the piston to bore clearance was tight and when I mean tight, less than 1 thou. 

Offline Crispy

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Re: 750 K1 project
« Reply #33 on: April 15, 2018, 02:01:30 PM »
OK, they need to be honed out until the lip is visible no more. Then you can get a true measurement  ;)
I know what all the books say to the max spec but, when this engine was new, the piston to bore clearance was tight and when I mean tight, less than 1 thou.

Cheers Trigger, I'll see about getting that done ...👍
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Offline Crispy

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Re: 750 K1 project
« Reply #34 on: April 16, 2018, 09:01:07 PM »
Checked the valves over tonight..looks like they and the guides will need replacing they failed on both the valve guide clearance and vertical run out measurements...by a large margin! doh! 😕  On a more positive note the springs are ok! 😊
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Offline Nurse Julie

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Re: 750 K1 project
« Reply #35 on: April 16, 2018, 09:06:12 PM »
Loving your upside down pics, is it a Derbyshire thing? 😀😀😀
Im a Nurse, trust me, this won't hurt.....much !!!

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Offline Crispy

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Re: 750 K1 project
« Reply #36 on: April 16, 2018, 09:10:52 PM »
Loving your upside down pics, is it a Derbyshire thing? 😀😀😀

Haha! Don't know why they appear upside down! They turn the right way up when you view them ! 🤔😂
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Offline Trigger

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Re: 750 K1 project
« Reply #37 on: April 16, 2018, 09:12:48 PM »
Checked the valves over tonight..looks like they and the guides will need replacing they failed on both the valve guide clearance and vertical run out measurements...by a large margin! doh! 😕  On a more positive note the springs are ok! 😊

The valve face is pitted, this is down to the valve clearance being too tight. These will need re facing  ;)

Offline Crispy

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Re: 750 K1 project
« Reply #38 on: April 16, 2018, 09:28:02 PM »
Checked the valves over tonight..looks like they and the guides will need replacing they failed on both the valve guide clearance and vertical run out measurements...by a large margin! doh! 😕  On a more positive note the springs are ok! 😊
u

The valve face is pitted, this is down to the valve clearance being too tight. These will need re facing  ;)

The valve seats look ok tho! 😬
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Offline Trigger

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Re: 750 K1 project
« Reply #39 on: April 16, 2018, 10:07:34 PM »
They will clean up but, if you have new valve guides fitted. The head needs to be about 300c in a oven and the guides need to be frozen to make fitting easy. The heat distorts the head a little so, a head skim and valve seats re ground. Not Cut  ;)

Offline Crispy

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Re: 750 K1 project
« Reply #40 on: April 17, 2018, 08:12:25 AM »
I've seen threads re pre honed guides on the US site... What's the score with these..do these do away with the need for reaming after fitting?  opinion seems to be divided?
« Last Edit: April 17, 2018, 08:15:15 AM by Crispy »
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Offline Trigger

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Re: 750 K1 project
« Reply #41 on: April 17, 2018, 08:39:22 AM »
There is plug and play valve guilds on the market for modern heads. They come as a set, valves and guilds, even today there are valves on the market that are Teflon coated so, you can't even lap them in. This is all apart of the throwaway society and making engineers in to fitters.
On these old girls, you should use the upgraded valve guides, that have oil seals on all. One of the best I have found are sets from Yamiya. These still need to be reamed with a Honda tool to spec.

Offline Crispy

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Re: 750 K1 project
« Reply #42 on: April 17, 2018, 06:46:51 PM »
Ok 👍  Thanks for that...ill probably end up farming that out! I've never reamed anything and probably not a good idea to start now! 😬
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Offline Trigger

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Re: 750 K1 project
« Reply #43 on: April 17, 2018, 07:47:45 PM »
Just make sure that they know about old Honda's and have the right tooling. I spend half my day correcting other engineers work  >:( And if they mention that they do brit bikes, RUN  ;)
« Last Edit: April 17, 2018, 07:56:44 PM by Trigger »

Offline Crispy

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Re: 750 K1 project
« Reply #44 on: April 18, 2018, 07:11:20 PM »
😂👍
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