Valve Clearance Adjustment.
 

Hello all. One of the next jobs I want to do on my B20 is check the valve clearances. I got a shiny new rocker cover and a new gasket so I guess now is the best time to be doing it. However the manuals are a bit vague on the subject. Has anyone got any advice or links to somewhere that has it in a bit more detail? Thanks, Hugh.

Hi Hugh

Yup, here is a very comprehensive way to check and set the valve clearance. Clicky! I have just used it for my B18 and it works wonders! I truely recommend it.

Bookmark vclassics.com, its really worth it for all the tech!

Dylan

The method using "exhaust just opening, then set inlet on same cylinder" and "inlet almost closed then set exhaust on same cylinder" advocated by Dylan's links works just as well as the time honoured "rule of nine" in the Haynes manual, except here is more room for error if you get it the wrong way round!

From a technical standpoint both put the cam on the base circle so the valve clearance should be at a maximum.

I use the rule of 9 method on the Amazon but some engines can't use this if the ports are not symetrical about the midpoint of the engine. I use the valve opening/closing method on my bike because it's a V-twin, so there's no way of referring to the other cylinder.

Rule of 9 (applies to B18, B20): Valve 1 rocker fully down, set valve 8,
Valve 2 rocker fully down, set valve 7, and so on.
The manual gives the order that the valves will open in. Just remember to write down the ones you have done so you don't miss any!

Thanks a million guys. Much appreciated:thumbs_up: Hugh.

I used to do it the haynes way on my B20F, but after trying the Vclassic alternative I never went back to the haynes. If you've done it a couple of times it becomes easy, the better/smoother running engine is worth the extra time imho.

Hi all, could someone give me a link where I can find the valve clearance data (1800E 1970). My poor old Haynes reprint is a bit vague!

Many thanks!

Google is your friend. It was quicker than pulling up the Green book on my hard drive.

"Injected B20s normally have the D cam, and the specs for that are .016 - .018 warm or cold. There is no problem going to the tight end of that spec."

Quote from Phil Singher.

That is Imperial of course ..
16 thousandths of an Inch and 18 thousandths of an inch ...

Thanks very much, both. Sorry for being such a div with the Google search!

Getting various different ideas, on order of adjustment. Are those measurements for hot or cold engine?

Do you have a Haynes manual? Lots of help there.

Same hot or cold.

Valve clearance video

https://m.youtube.com/watch?v=AVnnRSP2NCo

Try a google search, or search this forum before asking a question. Even if you don’t find your answer, you’ll learn something from your reading.

Cheers.