mercruiser 3.0 quick question on valve lash

richa311

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Ok I'm setting the valve lash according to manual and info I've found here.
My question is I'll adjust the lash so that I can't spin the rod with my fingers then tighten 3/4 turn more.

Why when I do the same to another valve or 2 why can I turn the rod again on cyl 1 for instance?
 
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You have to set the valve clearance when the valve is closed. So you have to get the motor at #1 TDC on compression and do certain ones, then rotate the engine one full turn and to the remaining.

Mercruiser 3.0 Valve Adjustment Video

 

Bt Doctur

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Or do each one by itself, Rotate the motor until an intake valve opens and closes. Now your on that cylinders compression stroke. Adjust both pushrods, and then move to the next cylinder again by rotating the motor until that cylinders intake opens and closes
The valve are E,I,I,E,E,I,I,E
 
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richa311

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Thanks I did it by rotating motor and when the 1 cyl valves didn't move as the pulley with the mark came up to the timing plate I set it at the 0 mark. I then adjusted the rockers specified in manual. Then rotated the motor 360 degrees and adjusted the remaining. But after adjusting say the 1 cyl as I worked my way toward cyl 4 I found that the rockers at cyl 1 had loosened up some before I rotated the motor.
Not sure if that's normal or not? Not real loose I couldn't move the rod up and down but could rotate it by hand.
 

richa311

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Could someone please verify the order of the exhaust and intake valves please? The video has the order different from the other 2 sources I found for an 89 mercruiser.
If the video is correct I'm going to have to re do this.

I have also been told you basically want to have 4 to 5 threads showing on all the rockers. Does this sound right?

Sorry just saw above that the order was listed.
Is that the order for all the 3.0 or just certain years.
The info I found for an 89 has the order listed as the following : ie, ei, ie, ei, going from cyl 1 toward cyl 4.
 
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richa311

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Ok I've done more research on this forum and found after you set the valve lash it's normal for it to loosen back up after it bleeds off. I'm going to have to re do them tomorrow as I'm afraid I may have over tightened a couple.

I still need a definite answer on the order of intake and exhaust valves for an 89 though. Even on this forum it's listed 2 different ways.
ie, ei, ie, ei
And
E,I,I,E,E,I,I,E

So what one is it? Why wouldn't the manual have listed that?

Also is the method of turning the engine over watching cyl 1 valves to be sure they don't move as your coming up to 0 degrees on timing plate. Then when at 0 adusting the corresponding valves. Then rotate 360 degrees and adjust the remaining valves the correct method?

Sorry but the more I read of the different ways the more confused I'm getting.
So I just need to be sure my method will work and I need to know the valve order.

Thanks again everyone for the help
 
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You can also do it with the engine running. It's a little messy but will be spot on. Seen it done many times as a kid watching the "old man". You fire it up and loosen the nut until the rocker starts to clatter, then slowly tighten it back until the clatter stops... that will be zero lash, then you go your half or 3/4's more of a turn past zero lash, slowly in 1/4 turn increments waiting 10 seconds between.

They do sell deflectors that snap on the rocker to help with the oil splashing.

I have no idea on how many threads should stick out.
 
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Bt Doctur

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the cast iron head for the 4 cylinder GM motor is E,I,I,E,E,I,I,E..
 

richa311

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Thanks everyone for the help. I re set the valve lash today using the correct valve order.
I tried it with the motor running 1st but the process was way to messy.
I did it with plugs out and used the method of finger over cyl 1 plug hole as explained in the video. It seemed to work well and all the rockers are adjusted at approximately the same area give or take a thread count on the visible threads on rocker bolts.
Boat idles fine and no valve clatter so it should be ok
 
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