positive stop method

[Hoffman Fisher]

Hi all, if using a bought positive stop tool, rather than a home made one, how far is it best to screw in - (1) just very slightly screwed.... or (2) screw until you can screw no more. Fnarr fnarr.
I'll away the jokes, but hopefully amongst them the answer will be found.

Cheers

[camel]

dosnt matter really does it....your going to half the difference to find tdc anyway with a timing disk anyway arnt you?....both ways will find the same point

[byron]

the further in, the less distance to measure betweeen the two points.
just make sure that the piston is not around TDC, you don't want to be winding the end of the tool into the crown...

[Hoffman Fisher]

Yeah, that's true, but I had heard that it was best to keep the gap between the two markings as close as possible, is this not the case or an irrelevant point.

[camel]

it does make life a little easier if their close together,ive partially wound it in trial and error to achieve this myself

[Hoffman Fisher]

Yeah! Same here, three turns in but wasn't sure if this then interfered with the squish. Hot starting issue, so wasn't sure if timing was off, pick up reads 93.8 and therefore hot starting could be down to low reading on pick up, I've read that it should be 95 - 120.

[byron]

the end of the tool would well away from the squish band...

I'd change that pickup

[Monty]

I used my home made one set up for my 186 Muggy on a mates new baby 200 muggy and couldn't find the top of the piston at all. Even screwing it out longer. Seemed the head was a different shape. So I thinks its suck it and see.

[paul213]

I use a pair of divders to find the centre point between the 2 marks (tdc) as there is no chance of me getting the maths wrong (again)