SoCal Jet Boats
Tech Talk => Jet Pumps => Topic started by: foxfury on June 01, 2011, 06:18:13 AM
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I have a vibration somewhere either in my engine or dominator drive I can't pinpoint. I pulled the motor to check the thrust bearing but it seems tight with no side to side play. What are the possibilities that I have an out of balance flywheel/harmonic balancer, or could it still be the thrust bearing?
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Have you verified that there isn't a rock in the impeller?
If you have the engine out, spin the pump by hand and see if there is any roughness in the bearing. My WJ had a growl noise when running but once apart had a noticeable rough front bearing.
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Has it ever been smooth? could be an alignment problem....
GT
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What brand motor? Have you checked to see if somthing is stuck in the pump? Cam going flat? Bad plug wire? We need more info. TIMINATOR
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motor is a 454. the shaft spins freely with no rough spots or tightness. I ran the motor today and have a noticeable vibration. Gonna change out plugs/wires and have the flywheel checked.
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motor is a 454. the shaft spins freely with no rough spots or tightness. I ran the motor today and have a noticeable vibration. Gonna change out plugs/wires and have the flywheel checked.
A miss is definitely different from a vibration......Has it ever run smoothly since you have owned it? (He says again with a little irritation in his voice) :D
An incorrect harmonic balancer can do what you describe, of course so could a thrown rod. :-\
GT
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I hate to admit it, but I once put the flex plate on backwards.
I thought it was going to rip the stringers out.
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I hate to admit it, but I once put the flex plate on backwards.
I thought it was going to rip the stringers out.
The flexplate was on my jet backward when I bought it, he actually thought the crank was broken... :D
GT
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The flexplate was on my jet backward when I bought it, he actually thought the crank was broken... :D
GT
I flipped the flex plate around after a weekend at the river. Ran it the rest of the season, even a trip to Powell. Tore it down in the fall and found a cracked crank.
Thats why I stick cabinets.
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Make sure that you've got the right flexplate/balancer to go with your crank. Stock cranks ate externally balanced....use offset balanced end pieces. Some aftermarket cranks are internally balanced and use neutral balanced end pieces
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I have a vibration somewhere either in my engine or dominator drive I can't pinpoint. I pulled the motor to check the thrust bearing but it seems tight with no side to side play. What are the possibilities that I have an out of balance flywheel/harmonic balancer, or could it still be the thrust bearing?
Just curious , is this a vibration you can feel ? and does it change or get worse/better with RPMs or is it a "stacato" noise you can hear (very iomportant!) Also may have missed this but is this new and has anything else changed or been changed Tom
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Not sure if the motor has ever run smooth. I bought the thing gutted and just recently fired up the motor. I can definetly feel the vibration and it speeds up when I rev the engine. No noise other than the rattle created (not in the engine). Im gonna change out the cap, wires and plugs and see what happens. IF IT EVER STOPS RAINING! thanks for all your help guys. ;D
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Turns out it was the harmonic balancer. boat runs like a top now.