Hayelp! Micra K10 valve clearances problem

[Station]

Apologies. I have ctrl+v'd this from another forum:

 

Hi

I have been currently trying to set the valve clearance on my K10 MA10 (1.0).

It needs 25mm on inlet and 30mm on exhaust side.

 

I set the pulley mark to '0' (this is at TDC on cylinder one), and the four as marked in the manual.

Then do the other set at oppostie TDC, as illustrated here:

 

 

Every time I've set it, I run the engine, it taps like Bruce Forsythe after he's had a few and when I recheck the clearances, they're either completely closed against the valve or have a huge clearance!!

 

What is going on?!

 

Addition!:

 

Is TDC on cylinder 4 opposite to TDC on cylinder 1 (ie 180 degrees)? That's how I've been doing it. Also tried screwdriver down the plug hole.

[Richard]

TDC on 4's compression stroke is 360 degrees from TDC on 1's compression stroke. Each cylinder of the engine takes two revolutions of the crank to complete the cycle. You know which one is on the compression stroke because both valves are closed, its opposite number will have the exhaust valve open.

[Junkman]

^^

This.

 

It takes two full revolutions of the crankshaft (720 degrees) for the camshaft to make one revolution (360 degrees).

Hence when you set it so that cylinder 1 is at TDC, and then do the respective valves, you then have to turn it a full revolution, i.e. again to the 0 mark, to have cylinder 4 at TDC, and do the remaining ones, because only when you turned it a full 360 degrees, the camshaft will have done the necessary 180.