BX24 D902 no compression after piston change

[cln2day]

Aloha

Had #3 connecting rod seize on crankshaft, Tractor ran fine on 2 cyc. but the pistion was falling and knocking on the crankshaft. Replaced crankshaft and new pistion and connecting rod with rings, New head gasket but now I have no compression in any cylinder. not sure what i could have done wrong putting back together. Have top dead center on flywheel and adjusted the timing to specks.

Any ideas on what i could have not done and why i have no compression?

The grass is growing long and need to get running

thx for any help

 

[kubotasam]

No compression on any cylinder suggests either the head is not seated on the block correctly or valves out of adjustment. Did you reset the valve clearance after replacing the head?

 

[cln2day]

I have set the push rods meeting the valve top if that's what valve clearance your talking about

R

 

[North Idaho Wolfman]

Did you pull the gears on the front?
Did you make sure to line them all up?

 

[cln2day]

Yes they are a lined up. Used the
WSM for the guide.

What really baffles me is that it ran great on the #1 and #2. I pulled it because didnt want thje piston to fall causing more damage. All the broken pices were found in oil pan so i know nothen ended up top.

Im stumped

Thanks for the help

 

[kc8fbl]

Did you stagger the rings on the pistons? If the ring gaps are all lined up in the cylinder, you won't have any compression.

 

[cln2day]

Yes I set the rings according to the WSM

 

[North Idaho Wolfman]

How did you determine you have no compression, pressure gauge?

The only way you really wouldn't get any pressure at all would be if you have the valves too tight and they are staying open, or they are completely out of time.

Even with ring gap lined up you would get a lower compression, but still not none, and it would correct it's self after a short time.

If you think it's a ring problem, take the injectors out and squirt a little oil in the cylinder and crank it a few times to force out the excess, install the injector and test the compression again.

 

[cln2day]

used a pressure gauge in the glow plug. could it have anything to do with the rocker arms? i did change the push rods and when putting together did notice that one of the three rocker arm bolts was bent and replaced all three.

 

[kubotasam]

used a pressure gauge in the glow plug. could it have anything to do with the rocker arms? i did change the push rods and when putting together did notice that one of the three rocker arm bolts was bent and replaced all three.

A 3 cylinder engine has 6 rocker arms so when you said "you replaced all three" it kind of makes me wonder. In my first response I asked if you set the valve clearance. It is an adjustment between the end of the rocker arm and the top of the valve stem.

 

[cln2day]

I replaced the three bolts that hold the rockers in place, was just wondering if I should look at rocker arms and their support.

 

[cln2day]

I replaced the three bolts that hold the support down not any rocker arms. The support looks ok and straight.

 

[kubotasam]

Sorry about not reading carefully enough when you were talking about the rocker arm bolts.
You should be able to track down where the air is going when it is not being compressed. Hold a piece of paper over the intake like a flapper. Then crank the engine. The intake should only move in. Do the same over the exhaust. It should only move out. Watch the valves open and close while turnig the engine over by hand. Do the all move the the same distance? Squirt some oil around the base of the head. Do you get bubbling? The air has to be going somewhere.

 

[cln2day]

Thx

Will try this weekend, short business trip till sat

 

[cln2day]

Was able to work on tractor today and when I try to start tractor i have compression blowing out both intake and exhaust. I turn over by hand and it seams that valves are opening opposite than what they should. I have taken rocker arms off and watch the push rods and I can't see how to make the valves open in the correct way. I know I lined up the marks on the gears.

Thx for the help

 

[snakebit95]

Camshaft timing is out. Only thing it can be if the valves are opening opposite of normal. Camshaft makes one full revolution for every two crankshaft revolutions.