Generator Raw Water Impellar

Hi,

Get a mirror and a flashlight and have a good look at where the pump is located, I find it hard to believe that the whole genset would have to be removed to replace an item like this.

If it really is this bad maybe you should look at fitting a remote mounted electrically driven cooling pump to it.

As I can only guess at the exact model no I have had a look at the Kohler website, the little ones like this all seem to be in boxes with all the connections at the rear but the actual Pump is crankshaft driven at the front of the engine inside the box.

What is the model of your unit?

Impellers dont' seem to last very long on kohlers. I woudl NEVER EVER buy a boat if i cant' easily get to the impeller on the gennies and mains... yet you see a lot of these... Sea Ray seems to have a patent on hard to reach gennies, making you crawl over hot engines, exhaust hoses, etc...

i dont 'think you need to pull the genny to get to the impeller but it's probably hard to reach. you may have to crawl over the engines, and over the top of the genny...

or hire a skinny mechanic.

Actually Ocean SF's, Searay's and Carvers are notorious for installing the generator in location where you can't replace the impeller.

You should be able to loosen one of the generator mounting bolts, and remove the other 3 mounting bolts and turn the generator 30 degrees or so without having to physically remove any of the wiring or hoses and be able to have enough room to change the impellor.

I quite keenly remember posting a reply to this thread. If the part made it a decade with out failing its not unreasonable for it to be very difficult to get too.

Do you know what an impeller is?

And generator and raw water cooling too. Even if I didn't its not unreasonable to put a component in where you can't easily reach it if it can make it a decade without failing. Its not ideal, but its not unprecedented.

How do you know it is the original impeller? I take them out every year and replace them every second even if they look OK. It is a maintenance item that you may need to check just about anytime...

The wording of his other post (which I read before this one) made it seem as if he has had the boat for a while ("recent problem" isn't something people say about a boat they bought 6 months ago) So I assume he has had it for a while, and the fact that he doesn't know how to change it would indicate that he has not yet changed it, and does not have a mechanic who would have charged him lots for removing the generator. The fact that he diagnosed a failed impellar due to a failure of the system and a clean filter indicates that he is comfortable with the kind of induction that would have revealed that the mechanic did or did not remove the generator so there would be no uncertainty in the post.

With your logic I wouldn´t need a fuel cap on my boat, as I have not needed to refill for three years and still have half a tank....

Please don´t answer.

I disagree

Well, I got the impression you wanted to learn something, but if you are here to teach, I have to go to bed now.

Hi,

What exactly is a failure of the system as written in your post?

How does the fact that the guy thinks he has a failed Impeller give any indication that the generator had ever been worked on by "the mechanic".?

As I wrote to you the other night, giving off base waffling answers does not endear you to anyone.

Whilst you might whinge about the low post to member ratio it is fortunate that the majority of posters here do not suffer the same nervous twitch that you do whilst typing.

Check the belt that turns the raw water pump first. You might be able to get in there with a lot of 3/8" drive extensions and a universal joint to basically unbolt the entire raw water pump from it's mounting bracket or where it attaches to the engine block.

K1W1: the original post had this sentence.

My reply basically said that it was believable. It was both on subject, and gave reasoning as to why it might be this way. Capt J's reply showed that my reasoning was correct (2 years instead of 10, Carver still thought it was worth the benefits to make that part difficult to get too). 10 years is not unreasonable for an impeller running in saltwater, Back in my highschool days I did some plumbing work on a filter system on a very large display aquarium, had a pump that had been moving 10 gallons a minute for 20 years stopping only for power outages.

"The mechanic" came in as the statement of an unstated major premise on my part to explain why I thought this particular impeller had made it so long, I was wrong on that point, but my original argument still stands. I took the time to explain myself, normally that would not be needed, but I was getting a lot of hassle for a very simple and factual statement (sometimes things are built in less than ideal ways).

Being so aggressive and dismissive probably doesn't engender anyone towards you all that much either.

Ask any mechanic of the most needed sparepart on any powerboat?

That's nice, but it was it a centrifugal pump or was it a Jabsco type with a flexible elastomeric impeller? I don't mean to insult an "almost scientist" but there are fundamental differences between the two types that by all appearances you are completely unaware..

Well firstly they are both impellers, and the choice of one over the other would be a manufacturers choice, there is no law mandating jabsco type impellers. Secondly I have no idea what type of impeller it was, The whole apparatus was installed 8 feet under the water line with a 2" feed in and out, and no shut off valves, so opening it up would have meant draining 2000 gallons of saltwater at the least. The inlet and outlet were both towards the top of the block, it was an ~18"X16"X5" block of UHMW with the axle ~3" higher than center point, the front ~3/4 had been sawn off with a bandsaw and was held on with bolts. Given the fact that I never saw the inside it could have been a very unbalanced gear pump, but seems to me to have been moving too much water for that. The gears in a gear pump are impellers anyways, and the Jabsco type is a simple mimicry of a gearpump.

If that were true at all you wouldn't have said "almost scientist" now would you?

This quizzing is tiresome for everyone, and its obviously not working, if you want to know any more about the pump feel free to pm me, I promise I'll respond.

As It stands the logic of "They didn't think it was too much of an inconvinience to put it in a difficult to reach spot" has stood up, and my assertation that some types of impellers can handle saltwater for a decade is pretty much irrefutable, the only valid argument would be "they didn't use one of those impellers on this boat", but that doesn't counter any claim that I made, so go right ahead with that one. I'm done with your childish game. By all means if I make a factual error correct me, but please stop with the Ad Hominem attacks.

You made a factual error. Like you have been told, a raw water impeller is something that you should be able to check and to replace in minutes.