350 Mariner Generator

[650Guy]

Hey All...

So I have a factory installed Kohler generator on my 2001 350 Mariner... But I am new to the boat.

So I'm new to having a generator. I start it up and she runs well, except I get very small amount of water out of the exhaust. Because i'm super paranoid, I have not run it for very long, maybe 3-5 mins MAX.

Here is what I know, but don't know if any of it matters:
- I have a closed loop cooling system
- Have completely cleaned sea strainer
- gen starts and seems to run just fine but have tried not to over heat her by only running in short spurts.
- right at start it seems to "mist" water
- a few mins after starting, it will blurb out maybe a cup of water then return to misting drops of water. This cycle seems to continue.

Does this sound like normal functionality? You will all make my day if you say "Oh ya man, thats how it works!"

also, do these things have overheat shut down protection?

[bud37]

Same boat , same genny....they burp water a bit but the flow should be relatively steady once the muffler is full......thinking you need to get the impeller changed and check for old bits in discharge to heat exchanger on the top there.You will not enjoy that job, if not handy it is definitely a pay and watch.
Just make sure that the thru hull valve is fully open and the strainer is full and no air in there first....Sorry bout that........

[Viper]

Unless a previous owner installed an exhaust/water separator with underwater discharge, you should get a good volume of water out the exhaust with the understanding that you have a lift muffler which will cause a pulsed action in the discharge. I'd also recommend replacing the impeller and inspect the inside of the pump housing and cover while you're there. Is your strainer below the water line?

[650Guy]

Well, you all have confirmed my suspicions.

I think a new impeller is in my future. I'm a hands on kinda guy but sometimes, its better to have someone who knows what they are doing do the job.

So dumb question, Bud37, you mentioned "once the muffler is full"... how long does that take? Also, I replaced the water line to the strainer over the winter, could there be air in THERE causing me issues? I did not even think of that part til you mentioned it.

[bud37]

The muffler fills quite quick, only a few seconds really....regarding the impeller its more of a, can you fit in there job to be done with a mirror etc, because of the location, not hard at all just time consuming frustrating when you can see something but not touch it, but well worth a try though.
It is possible that air is causing a problem but if the strainer is full, lid sealed and clamps all tight a good pump will pull. Those 3600 rpm gens can eat impellers, just the nature of them.Good luck man......

[mjk1040]

Once you have it repaired and running properly, use it every time you can with a load. Use it or loose it!

[650Guy]

Well, replacing the impeller seems like a prudent idea regardless. According to the last owner, it was replaced 2 years ago. I like doing it every other year on engines so this seems like a good time to do it.

I'll keep ya posted, I'll try and find the part number and get it on order.

Thanks everyone! This forum is priceless!!

[bud37]

One last tip, if you happen to remove the entire pump from the gen.....there is a plastic drive gear type mechanism ( coupling ) that drives the pump from the shaft...it will be obvious...get a new one and replace it and keep the old one as a spare....if you don't take it off, no sweat, just came to mind reading this again.

I guess my assumption is you have the kohler 7.3...yes

[650Guy]

You may be my new hero! That is an AWESOME TIP! I'll order up that gear as well! I know its a Kohler, and I assume its the 7.3, but will have to double check.

[Keith S]

Always post the model number to get relevant advice. If it is a 7.3, it is a plastic drive coupling, not actually a gear. The original black colored ones would crack and slip. They were replaced with an updated yellow coupling which has been pretty trouble free unless the pump seizes. Kohler recommends replacing the impeller every year regardless of hours on the 3600rpm units. The impeller hub has a tendency to slip even if the blades have little wear.