17 replies to this topic

[dklawson]

The socket extension (or other tool) method would certainly work as long as you got the tool back in exactly the same location on the piston (touching the head in exactly the same spot). Remember that the A-series heads have some interesting curvatures in the combustion chamber area.

[Se7enS1ns]

Thats very true. Reason i say socket extension is because its something most people have handy. I happened to have a length of brass pipe the exact diameter of the plug holes, so used that, but any long object would do it to a certain degree. Its a bit of a quick fix for those that dont have a DTI guage, or fancy pulling the head off.

[Danny Boy]

I read a really simple way of doing this on an assembled engine. Fashion a pointer as detailed above. Any form of pointer will do. Whip out a spark plug and push a ratchet extension into the hole. Turn the engine by hand til it stops against the extension, and mark the pully in line with the pointer. Then turn the engine backward, almost one full turn until the piston once again stops against the extension, and mark the pully again.

Exactly half way between these two marks is a pretty accurate TDC mark. Bingo.

Ok i tryed this method of finding tdc i used a longish nut and kept it flush with the plug hole so i knew it was always in the same place! and i found the point exactly in the middle. Got my timing light out and the point which i marked at tdc was about 90 degrees out!! i tryed turing the dizzy to get it to the right place but it certanly didnt like it! i have left the dizzy in the place where it gives the best results and it drives ok however it wont rev to the red line and the revs at idle are unsteady (they will dip every second or two) it also overheats if you keep your foot all the way to the floor as it stuggles to accelerate have i messed up the timing thing somehow or could it be fueling?? ive tryed my best with a colourtune but i cant seam to get on with it and find it inaccurate would it be worth buying a gas analyzer?