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alhendo1

Screw and locknut tappets

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alhendo1

Possible daft question alert!!... Do screw and locknut tappets have to be adjusted stone cold or can they be adjusted while there is still residual heat in the engine? 

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Dunnster

No daft questions, maybe silly replies  but eventually you'll get the correct answer.....:D

Ive always done mine stone cold.

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Argyll

Obviously best done stone cold but I believe that some garages do them after 2 or 3 hours resting.

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Grumpy old man

For the NC range stone cold, that's why the dealer needs the bike in the night before to allow the bike to be cold when they do the job. 

At least they did with mine.

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Andy m

Stone cold for me. I doubt anything would be that bad if it had the oil changed first thing and the valves done mid afternoon, at least not in the UK climate, but it isn't a one day, collect at lunchtime job. 

 

Andy

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SteveThackery

It varies with the particular bike, though.  For example, my first Indian Royal Enfield had a tappet clearance of zero, set when the engine is "warm", whatever that means!  It was a pushrod engine, unlike the NC.

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Tex
4 hours ago, SteveThackery said:

It varies with the particular bike, though.  For example, my first Indian Royal Enfield had a tappet clearance of zero, set when the engine is "warm", whatever that means!  It was a pushrod engine, unlike the NC.


Does the Enfield still have the tappet adjusters at the bottom of the barrel? Can’t argue about ease of access with that system! ;) 

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SteveThackery
15 hours ago, Tex said:


Does the Enfield still have the tappet adjusters at the bottom of the barrel? Can’t argue about ease of access with that system! ;) 

 

No, the current engine has hydraulic lifters.

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slowboy
19 hours ago, SteveThackery said:

It varies with the particular bike, though.  For example, my first Indian Royal Enfield had a tappet clearance of zero, set when the engine is "warm", whatever that means!  It was a pushrod engine, unlike the NC.


It means not cold and not so hot you resort to early Anglo Saxon to express how hot it actually is.😁

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davebike

Jap bikes 

I was taught  "cold" and "cold" defined as not hot to the touch  This was Suzuki GB long ago  but same princable used at Yamah and Honda dealers I worked at  and I used fro "cough" years !

 

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Andy m
On 13/09/2020 at 09:57, SteveThackery said:

 

No, the current engine has hydraulic lifters.

 

Which given they fit in almost the same tube as the old pushrods, it's pretty hard to forgive them for then switching to shims on the 650's.

 

To put the numbers into context a 100 degree rise in temperature will cause a 6 inch long steel pushrod to expand by about 3 - 4 thou. A typical valve feeler is 8 or 10 thou, so a hot engine will result in error of maybe 50%. At room temperature, be it on the radiator after my wife set the thermostat or after she broke the boiler, its all the same. Its just humans that are very good in the range 15 to 30 C. 

 

Andy

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Argyll
40 minutes ago, Andy m said:

 

 it's pretty hard to forgive them for then switching to shims on the 650's.

 

 

Which bike are you referring to?

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SteveThackery
1 hour ago, Andy m said:

 

Which given they fit in almost the same tube as the old pushrods, it's pretty hard to forgive them for then switching to shims on the 650's.

 

 

Is the 650 a pushrod engine?  I just assumed it was OHC.

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Tex
2 hours ago, Argyll said:

Which bike are you referring to?

 

1 hour ago, SteveThackery said:

 

Is the 650 a pushrod engine?  I just assumed it was OHC.


I think it’s OHC with screw and locknut adjusters. It’s definitely the latter! 

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SteveThackery
Just now, Tex said:

I think it’s OHC with screw and locknut adjusters. It’s definitely the latter! 

 

I thought so.  So hydraulic lifters aren't used because they take up too much space in a motorcycle cylinder head.  :)

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Argyll

Interceptor-tappets.jpg

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RC166

Nice piccy Argyll! Is that with a proper camera or phone? Any enhancements to get the desired result? 

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Argyll

The pic was taken with my 2yr old Motorola G6. It does have a fairly decent camera though. The problem, of course, is trying to work with a touchscreen whilst wearing oily nitrile gloves!

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Argyll

It's not so good under artificial light though (see pic below), but it's handy. I sometimes use my Sony RX100 but I try to keep it oil-free :)

 

DSC01253.jpg

 

 

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RC166

That looks a nice restoration job. Interested to hear all about it! 

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