Mercruiser 4.3 valve adjustment

[bluesdude]

Putting together my 1989 4.3 after rebuild and am at valve adjustment. The Seloc manual says to turn the engine to #1 firing position and adjust certain rocker bolts until you cant turn the pushrod then tighten 3/4 turn. Phase 2 is to turn the crankshaft 1 full turn back to the timing mark where #6 cylinder is at its firing point. The problem is that #6 is not at its firing point then. It seems to me that the fourth cylinder in the firing order should be at TDC at that point which is cylinder #4. Is there a misprint in the manual? Second question..when I make the 3/4 turn adjustment and turn the engine back to #1 TDC, the pushrods are loose enough to turn by hand again. Do I re-adjust or is this from no oil pressure in the hydraulic lifters?

 

[earnies2]

Re: Mercruiser 4.3 valve adjustment

I just take the freeplay out than start the motor than ajustthe valves. remove v/covers or cover if you want to do 1 side at a time you can purchage a set of oil deflecters from your local auto parts store, they will deflect the oil that squirts out of the rocker arm and makes a mess also place a peice of caurdboard in the bottom of the head to catch the oil from the rockers,get it running tighten down anny loose rockers than start from the front loosen the rocker until ti ticks, tighten it down until it is quiet than go 3/4 to 1 turn further your done one down 11 more to go Good luck

 

[xltier]

Re: Mercruiser 4.3 valve adjustment

if you start at #1-back off the rockers till be sure to turn in the direction of rotationloose,then tighten down while twirling the pushrod with your finer and thumb till tension is felt.you will be against the spring in lifter at that point.adjust both valves there.turn crank pulley 60 degrees or 1/6th of rotation and do next one in the firing order.when all 6 are done you can than tighten them all 3\4 turn.no mess that way.be sure to turn in direction of rotation.

 

[achris]

Re: Mercruiser 4.3 valve adjustment

Bluesdude,<br /><br />Here's the best thing to do.<br /><br />1. Pick up your Seloc manual<br />2. Walk to your trash can<br />3. Deposit said manual in aforementioned trash can<br />4. Buy real manual, ie Factory genuine.<br /><br />To adjust valves, do just as Xltier says with one correction (it's a 4 stroke and fires every 120 degrees).<br /><br />

If you start at #1-back off the rockers till loose,then tighten down while twirling the pushrod with your finger and thumb till tension is felt. You will be against the spring in lifter at that point. Adjust both valves there, then turn crank pulley 120 degrees or 1/3rd of rotation and do next one in the firing order. When all 6 (you will have turned the engine 2 full rotations) are done you can then tighten them all 3/4 turn. No mess that way. Be sure to turn in direction of rotation.

Chris...........

 

[bluesdude]

Re: Mercruiser 4.3 valve adjustment

AChris,<br /><br />Manual deposited. Any view on question #2?

 

[KaGee]

Re: Mercruiser 4.3 valve adjustment

On the V-6, one revolution of the balancer is TDC for #4. <br /><br />With #1 cylinder @ TDC, Adjust intake on 1, 2 and 3. Adjust exhaust on 1, 5 and 6.<br />With #4 @ TDC, adjust intake on 4, 5 and 6. Adjust exhaust on 2, 3 and 4.

 

[achris]

Re: Mercruiser 4.3 valve adjustment

Bluesdude,<br /><br />There are a couple of way to determine firing order.<br /><br />1. Read from decal on engine rocker cover.<br />2. Should be cast into the inlet manifold.<br />3. Use correct engine service manual.<br />4. Follow each spark plug lead and see which cylinder they run to. Remember that GM number their cylinders differently to Ford. GM start with the front port as #1 then front starboard #2, then centre port #3, you get the idea.<br />Each cylinder number is cast into the inlet manifold ajacent to the cylinder. (I may have the port/starboard around the wrong way, I'm not anywhere near a manual.)<br /><br />Usually for the 262 engine the firing order is 165432.<br /><br />

Second question..when I make the 3/4 turn adjustment and turn the engine back to #1 TDC, the pushrods are loose enough to turn by hand again. Do I re-adjust or is this from no oil pressure in the hydraulic lifters?

DON'T re-adjust, you are right about the lack of oil in the lifter.<br /><br />Chris.................

 

[bluesdude]

Re: Mercruiser 4.3 valve adjustment

Thanks for the help.

 

[Bt Doctur]

Re: Mercruiser 4.3 valve adjustment

why not just start on one bank ,rotate untill intake opens and closes and adjust. then do the next one in line.