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Tappits ? what the heck are they ?


polecat
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Question to one of you Smart Ones !

Mechanic said I need to adjust the tappets and could do it myself in a couple of hours.

What the heck is a tappet and why is it not mentioned in my HAYNES manual ?

How hard is it to do them when I find where they are and if they exsist ?


Mechanical Noob so be gentle :D

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Guest Hodgy

Tappets = valve clearances


You'll need feeler guages, remove valve cover, check clearances with engine cold usually, but it should tell you in the book, adjust if necessary, again Mr Haynes should tell you what the clearances should be and how to adjust them :)

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Tappets = valve clearances


You'll need feeler guages, remove valve cover, check clearances with engine cold usually, but it should tell you in the book, adjust if necessary, again Mr Haynes should tell you what the clearances should be and how to adjust them :)

ah so tappeets are now valves :!: ok relook at Haynes :cheers:

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No, tappets are not valves mate. They used to be the screw and locknut that you use to adjust your valve clearances. Modern engines tend to have shims on top of buckets that sit on top of the valves. You can,t adjust shims, you have to change them. If you come to Winster, we,ll have a go?

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they are the locknut and screw type on those engine you need to remove top engine cover to get to them

and need to use feeler gauges to set correct gap between rocker and valve

Ok I may feel brave enough to give it a go next week :)

can you damage the thing running it badly adjusted ?

 

Google not working then 8-)


http://en.wikipedia.org/wiki/Tappet

Its working but I wanted more hands on info than internet can provide and I imagined tappets to be somethng that Taps and valves as something that stops air coming out of it !

Haynes does not mention tappets at all :roll:

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they are the locknut and screw type on those engine you need to remove top engine cover to get to them

and need to use feeler gauges to set correct gap between rocker and valve

Ok I may feel brave enough to give it a go next week :)

can you damage the thing running it badly adjusted ?

 

You run the risk of bending the valves if they are too far out

Not done any for a long time but I recall something about the cylinder needing to be top dead center (TDC)

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Valve clearance should be checked and set when cam lobe is opposite valve. At tdc some valves are closed, some are open and some are in between. Turn crank clockwise until you see a cam that is opposite the valve, ie valve is fully closed, then check clearance. Turn crank some more until you can repeat this until all are done.

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Valve clearance should be checked and set when cam lobe is opposite valve. At tdc some valves are closed, some are open and some are in between. Turn crank clockwise until you see a cam that is opposite the valve, ie valve is fully closed, then check clearance. Turn crank some more until you can repeat this until all are done.

 

On modern bikes there are have two unscrewable covers. One revealing the nut to turn the engine and one to make sure its lined up at the right point. The haynes should show how.


Tappets are easier to live with tbh. Just screw the adjusters up and off you go.

Modern bikes now have you take out the shims and have you check with a micrometer that they are the right thickness. If they are worn and this wear matches the extra clearance on the valve you replace the shim no problem. If not you use the feeler gauges to work out the clearance and then buy an extra sized shim to boot.


At a bikes first valve clearance (usually 13,000 - 18,000 miles) there should be nothing in it. Its only when you get 50k miles plus I've ever seen a valve clearance be out.

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At a bikes first valve clearance (usually 13,000 - 18,000 miles) there should be nothing in it. Its only when you get 50k miles plus I've ever seen a valve clearance be out.

 

every bike that I've ever done has always needed adjusting at the first service and not needed doing again for the next two or three services, had to change 15 of 16 shims on mine at the first (15thou) service.




you shoud always check vavle clearances when the engine is stone cold.

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