Mower deck Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged

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bertsmobile1

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  • / Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged
Electric clutches have a brake fitted to them.
Legal requirement to make the blades stop after "X"seconds / rotations when turned off.
If the pulley is fouling on the deck then the routing is wrong, the belt is too long or the tensioner arm pivot is flogged really oval
The idler pulley should not come anywhere near the frame.
The tensioning spring should move the pulley towards the other pulleys.
Are you sure that the arm is on the right way round.
The spring should pull the short end of the lever left ( sitting on the mower ) towards the frame causing the pulley to move right towards the other pulleys and the belt prevents this happening.
 
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veekay

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  • / Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged
Pretty sure it is on the right way - same way it has been for a number of years.

I did find that the clutch was seized because I tightened the 3 screws around it. I guess when those are loosened or tightened it controls how much force it takes to spin. Loosed up all the way and even after the blades are disengaged the wheel keeps spinning. Too much and it doesn't move. Have it somewhere in the middle right now. Still having the issue of the idler puller slamming against the frame though. If I start the blades at the highest position it is much better, but on the lowest setting it is just a hair away.

bertsmobile1 said:
Electric clutches have a brake fitted to them.
Legal requirement to make the blades stop after "X"seconds / rotations when turned off.
If the pulley is fouling on the deck then the routing is wrong, the belt is too long or the tensioner arm pivot is flogged really oval
The idler pulley should not come anywhere near the frame.
The tensioning spring should move the pulley towards the other pulleys.
Are you sure that the arm is on the right way round.
The spring should pull the short end of the lever left ( sitting on the mower ) towards the frame causing the pulley to move right towards the other pulleys and the belt prevents this happening.
Click to expand...
 
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bertsmobile1

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  • / Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged
You should not touch the 3 screws on the clutch unless necessary.
They adjust the position of the clutch plate.
Most are around 0.010" between the clutch plates.
When you remove the belt does the tension arm move across to the right side & almost touch the other pulleys ?
If not then the deck is not set up right.
If it does do that then you have excessive wear in the pulleys or a belt that is drastically too short
 
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veekay

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  • / Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged
Far too late for not touching them. Any idea how freely the clutch should spin? Might help with adjusting them back.

Yes, without the belt the arm moves and sits next to the other pulley.

I found out the problem with the belt wasn't so much that it was too short, but that the dimensions of the belt angles are wrong so it doesn't sit against the pulleys as well. That adds up over each pulley and then causes it to pull too much.

bertsmobile1 said:
You should not touch the 3 screws on the clutch unless necessary.
They adjust the position of the clutch plate.
Most are around 0.010" between the clutch plates.
When you remove the belt does the tension arm move across to the right side & almost touch the other pulleys ?
If not then the deck is not set up right.
If it does do that then you have excessive wear in the pulleys or a belt that is drastically too short
Click to expand...
 
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ILENGINE

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  • / Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged
veekay said:
Far too late for not touching them. Any idea how freely the clutch should spin? Might help with adjusting them back.

Yes, without the belt the arm moves and sits next to the other pulley.

I found out the problem with the belt wasn't so much that it was too short, but that the dimensions of the belt angles are wrong so it doesn't sit against the pulleys as well. That adds up over each pulley and then causes it to pull too much.
Click to expand...

The clutch won't spin freely because of the brake. Next to each of those bolts on that clutch should be a slot about an inch long. You insert a .012-.016 feeler gauge between the two rotating plates and slowly adjust all three bolts to get the same clearance between the plates all the way around. Don't change each bolt more than about 1/4 turn at a time because when you adjust one bolt it will effect the clearance on the other two.
 
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veekay

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  • / Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged
Thanks - glad I actually own a set of feeler gauges.

ILENGINE said:
The clutch won't spin freely because of the brake. Next to each of those bolts on that clutch should be a slot about an inch long. You insert a .012-.016 feeler gauge between the two rotating plates and slowly adjust all three bolts to get the same clearance between the plates all the way around. Don't change each bolt more than about turn at a time because when you adjust one bolt it will effect the clearance on the other two.
Click to expand...
 
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ILENGINE

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  • / Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged
veekay said:
Thanks - glad I actually own a set of feeler gauges.
Click to expand...

My reply should saw 1/4 turn at a time not a full turn at a time. Went back and edited my original reply.
 
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bertsmobile1

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  • / Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged
veekay said:
Far too late for not touching them. Any idea how freely the clutch should spin? Might help with adjusting them back.

Yes, without the belt the arm moves and sits next to the other pulley.

I found out the problem with the belt wasn't so much that it was too short, but that the dimensions of the belt angles are wrong so it doesn't sit against the pulleys as well. That adds up over each pulley and then causes it to pull too much.
Click to expand...

Sounds strange.
Husqvarna use standard A & B profile belts however you must use wrapped belts, not standard raw V belts like a car fan belt.
These get sticky when they get hot and will not run clean for the short time till they break.
 
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veekay

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  • / Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged
I ordered an original belt versus the generic one. I did at least get things going enough to mow today. I can't engage the blades on the storage (highest) setting, but the others work well enough.

I wasn't able to get the clutch bolted in as tightly as I'd like since there is nothing to lock into place when tightening the bolt.
 
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bertsmobile1

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  • / Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged
Remove one spark plug and rocker cover.
Rotate the engine so that cylinder is bottom dead centre on compression stroke.
Feed as much nylon rope ( plated rope is better ) down the plug hole as you can then rotate the engine to compress the rope.
That will hold thee shaft while you tighten the bolt the turn the engine back a little and pull the rope out.
 
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