Marine Power 340 Pulley Wobble

[COguy15]

Hello,

I have an MP 340 on my 08 tige v-drive and it looks like my harmonic balancer and possibly circ pump is wobbling. Please see attached video. It has a brand new raw water pump and the pump flange is mated properly to the crank pulley/balancer. Also, I think that hum in the video is my alternator maybe? Thanks!

 

[Scott06]

Yeah not perfect but i wouldn't sweat it too much the water pump is worse, maybe there was corrosion or imperfect fit/ burr between pulley and water pump flange

 

[COguy15]

Yeah not perfect but i wouldn't sweat it too much the water pump is worse, maybe there was corrosion or imperfect fit/ burr between pulley and water pump flange

Yeah I’m trying to figure out if it’s the pulley or pump assy on the circ pump. I though there might’ve been something on the crank pulley so I pulled it off and checked fitment, fits perfect so I don’t know. Here’s a different angle

 

[NHGuy]

I come from the world of wheels and tires so I have seen a ton of spinning objects.
I do not know what is acceptable movement in those crank mounted pumps. When I focus on the brass pump I can see that it moves as the pulley and shaft under it spin. The crank pulley looks stationary from that view, but I wonder if it is, because the front belt moves quite a lot more than I'd want in my 5000 rpm engine. To really be sure of the crank pulley, hold something near it for a visual reference, but hold it on the "off" side so that if it somehow touched the moving parts it could not catch or jamb.

Also, the upper pulley is making visibly imperfect rotations.
Was the upper pully removed or replaced or was the engine circ pump beneath it serviced?
The front edge of that upper pulley has vertical runout. That makes the whole upper section of that front belt move up and down. Is it loud or shaking?
You could remove the pulleys and clean off the mating surfaces on the pulleys and mounting flanges beneath them. Maybe use one of those air driven 90 degree disc cleaner tools with the Roloc discs. A lot of us have those for car hubs and brake rotors.
That will get you a flat mating surface. And if the holes have paint or corrosion you can wire brush them.

 

[Bt Doctur]

donr see the side support for the pump

 

[dubs283]

donr see the side support for the pump

it's there, you can see it in the second video, right side of the pump

the pump will have a bit of movement due to the concentric shape of the housing. its possible the bushing on the support is worn and allowing excess movement

as far as the water pump pulley/balancer movement it does not appear the pulley is wobbling, just one portion of the outer edge has a "bump" for lack of a better term. possibly pooled paint from factory coating? balancer and pulley both seem to be rotating evenly when compared to a background reference

the belts seem to have excess movement, are they tightened enough or perhaps worn? standard deflection is no more than 3/4"