2005 Speedster 200 375hp Cavitation

[lilngineer]

Hey guys,

Just bought this speedster 200 this season with very low hours (16). First several times I've had the boat out its ran perfectly with no noticeable issues. The last 3-4 times I've had it out recently, I've noticed it's having a hard time getting out of the hole onto plane. It seems to be revving and not moving much until it finally builds up enough thrust. I thought for sure the wear rings were the problem but I pulled the pumps tonight and the impeller and rings look pretty good. No big gouges or gaps. I did however notice in the process that my intake grate tines appear to be a little bent in different directions from each other. The question is, would this cause out of the hole cavitation? Once I get the boat on plane it runs fine. I hit rpms and top speed. The problem is strictly out if the hole and has definitely developed since I bought the boat. Any ideas?

Also, does anyone know the allowable clearance between the wear ring and the impeller on the 185hp 4tec?

Thanks,

 

[KK40384]

I doubt that the grates will cause that much cavitation at low speeds. As far as the gap goes you shouldn't be able to slide a business card between the impeller and wear ring.

 

[lilngineer]

Another thing I noticed when I removed the pump was that one of the impeller boots was missing. Could that cause it? Has anyone ever seen one disappear?

 

[KK40384]

Yes that can definitely cause that. Or even one that spun off and is loose on the drive shaft. I have never seen one come completely off but there's a first for everything. I'm willing to be something went through that pump on sliced it. They are fairly strong. It is possible that it just got brittle with age and just came apart. Easy fix though.