Logo
FULL SITE MENU

LocateTDC

C

cdalton

New member
"Hi I have a 1996 Mercruiser 1

"Hi I have a 1996 Mercruiser 140 30.lx (model 4-30L 000JS)

I'm trying to adjust the timing but cannot read the timing marks on the plate, labels have worn / rusted, not sure which of the marks refers to TDC.

My timing plate has 6 points with no distinguishable markings / labels unlike the manual that shows 5 points and a deep notch for TDC. On my plate all notches are the same size.

Anybody know which mark is TDC?
Cheers

Cliff"
 
"Your best bet may be to slowl

"Your best bet may be to slowly rotate the crank back and forth using a socket and breaker bar on the damper nut, while feeling for TDC thru the #1 spark lug hole with the eraser end of a pencil. This can really help when all else fails.

Rod"
 
"Be careful with the pencil me

"Be careful with the pencil method as the piston will come to TDC on both the compression stroke and the exhaust stroke. It may be easier to plug the #1 spark plug hole with the tip of your finger as the piston is coming up to TDC. If you feel pressure and get a woosh of air when you remove your finger, it is on the compression stroke and this is where you want to be. No pressure would mean that the piston is on the exhaust stroke."
 
"buddy;

Good point, but TDC

"buddy;

Good point, but TDC is still TDC, on either part of the cycle. It does not matter which as far as finding where the right marks are.

It certainly does matter if you are reinstalling the distributor and timing it to the camshaft. You need to know that you are at TDC on the compression stroke in that case.

Rod"
 
"Don't use a round file an

"Don't use a round file and don't leave the pencil in the hole when turning the crank.
I did both of these. very bad things will happen. I learned a whole new definition or fishing.
angry.gif
"
 
"To Turly find TDC you need a

"To Turly find TDC you need a piston stop and a degree wheele
Rotate motor both-ways to piston stop, recording the position on the degree wheele. split the difference and you have TDC"
 
Back
Top