I had a similar problem heading down to Santa Cruz last summer. For my issue, it had gotten a small air bubble into the line and the bubble caused the engine to not want to run at 22rpm's, dropped it down to 1500rpm's and I could keep going into HMB. I did also change all the filters. No issues since then.

Erv,
Filter recomendations have been discussed before, and I think the concensus was to have a 30 micron as a primary filter (Racor), and a 10 micron secondary filter (on the engine). I think a bigger concern is the condition of the fuel in your tank. Is it contaminated? With what? Microbes? Water? Both? Until you solve the source of the problem, you will continue to have problems and not have confidence in your engine. Do you filter the fuel before it goes in (with a Baja type filter)? Do you add a biocide with each fillup (such as Biobor)? BTW, you should! Did you change your primary fuel supplier? Have you checked the plastic fuel filler cap? They are notorious for developing cracks and letting water into the fuel tank. If in doubt, replace it. You can get a new one from Catalina Direct. From your hull number, I'm guessing you have a M25XP? I ran a few thousand gallons of diesel thru mine and never had a problem. It is most likely not a problem with the engine, it's most likely the fuel. Hope this helps.

PS-Not sure what you mean by filter/evaporator? Nothing should be evaporating. The Racor-type filters separate water from the fuel by letting it settle in to the bowl. Let too much water accumulate in the bowl, and it gets into the engine. Not good.

Erv, I have been using that fuel dock for the past 12 years, ever since the one at Grand marina closed 'cuz their fuel tank started to leak. I have never had a problem with their fuel. We use our engine well more than 100 hours per year. While I agree conceptually with Tom, this simply hasn't been my experience with this fuel dock. They have a large turnover of fuel, since they are the ONLY place for miles around. I recommend you check your system very carefully first. We use a 2 micron primary R24S and the standard 10 micron engine mounted secondary filter. Never a problem with water or anything else. I use BioBor and Starbrite WaterZorb. Reply #7: [url]http://c34.org/bbs/index.php/topic,1124.0.html[/url]

Have you removed the pickup screen inside your tank? Have you replumbed your tank/filter/pump? Is your pump filter clean? Lotsa other reasons than just new fuel. See our Critical Upgrades topic on our C34 'Board which covers a variety of these "sins"...

We were ALL rookies at one time, and that's why this website and ours are designed to help you avoid reinventing the wheel.:):):)

There purpose of filtering the fuel is to remove contaminants. The system does not care which filter is doing the work. On the C34 it is so much easier to change the racor should it become fouled than the filter mounted on the engine, so most of us use a 2 or 10 micron Racor and a 10 or 20 micron engine filter. I have no experience with the C36 fuel system, so ask yourself....in a bouncy seaway with a hot engine that has just quit, which is the easiest filter to change to get the engine running again. Put your small micron filter there.

Air getting into the system is a possibility. Check that all the fittings and caps on the Racor housing are tight and not cracked/o rings in good shape. A friend chased a similiar problem for months. Turned out to be a leak in the cap that covers the manual prime pump.

When I learned about both screens at the pickup tube and in the fuel pump from this website I was stunned by the muck and accumulated crud. After removal of the tank screen and replacing the pump screen , the pump went from making a weak click every 5 seconds to a continuous purr. Biocide and water treatment is clearing out the tank. Thanks again for an informative and interesting site!

Most eng techs will tell you to take the screen off the pickup tube and let the filters, which are easier to change, do the filtering.

FYI, I had a problem a couple of years ago and one problem I found, which didn't relate to the fuel line clogging, was that the pickup tube in my tank was about 4" off the bottom of the tank. As a result, it wouldn't pick up fuel even though I still had gal's left. This could hve been a problem in rough seas with the fuel slopping around.

It seems someone tried to pull the tube up thru the nut device that secures it in the tyop of the tank. The bottom part of the pickup tube is a flexible hose that slips over the plastic tube that piece wont it thru the nut thus it was pulled off and laying in the bottom of the tank.

Erv
You are fortunate to have had some great advice from a few of the most knowledgeable Catalina guys around and I can't match their experience.

For what its worth, in my case I bought a relatively new boat but have always been really worried about engine unreliability caused by contaminated fuel.

It may have been overkill but I took the tank out of my boat and cleaned it and flushed it with methylated spirits on the dock. I took a few old 4 gallon drums to the boat and pumped the old fuel into them and disposed of it. There was a fair bit of water there.

It was not a really difficult job on the Mk11 but from day one I was absolutely sure the tank was clean.
I only fill it from a 4 gallon clear jerry can so I can see what goes in. I change the filters every 2 years as I only do about 50 hours a year and always add biocide.
I would suggest that if you have any doubts after checking for air leaks etc, empty the tank, and start afresh.

Erv,

As mentioned in the email I sent you the electric fuel pump must work or the engine would never run. It may be not putting out enough and there are screens in the pump that could be restricted and not allowing enough flow at higher power.

I had responded with some other suggestions but, did not understand that this ocured right after refueling. If that is the case it would lead me to believe it is fuel related and as mentioned the pick up tube in the tank may be plugged and restricting flow. I think there is some chatter on this forum about the screen in the electric pump.

[QUOTE=ervbo;9147]Could it be the fuel pump? One of the guys in the marina things that is it. My engine runs beautiful forever at idle but once I take it out of the marina it gradually dies out by the time I get 100 yards out. The guy says I have an electric fuel pump and he doesnt hear it when I turn the key on and I should be able to bleed the air out without having to start the engine. I guess since its easy to get out and swap it might be worth a try but thought I would get your guys thoughts, first. Thanks, again[/QUOTE]

Erv, we just had this discussion. [url]http://c34.org/bbs/index.php/topic,6429.0.html[/url]

Please note that this is for newer engines with glow plug and fuel pump wiring that MAY BE, and most likely is, different that your boat's setup. Given the age of your boat, your fuel pump should work just like mine: ignition switch ON, pump runs. Simple.

Please spend some time reading the links involved, too.

You may not have this wiring, and probably don't, but your dockmate is right: if your fuel pump doesn't come on when the ignition switch turns on, check the wiring to it first.

The do all the rest of the stuff this thread discusses: fuel pickup screen, bottom of fuel pump filter (?clog), fuel filters, proper routing of fuel from tank to Racor to pump then to engine...

The time to discover that the engine stalls under load is not when you're away from the dock, but when you're tied to it. You can run the engine at higher power while you're in the slip. Just tie the boat securely with (good, strong) dock lines, making sure there is nothing in front or behind the boat that it might contact when the dock lines stretch. Then run the engine in gear exactly as you would normally. I have put mine in gear, running at say 2000 rpm, then gone off for a couple hour lunch. The boat's happy 'cruising' at the dock, I'm happy at lunch, and when I get back to the boat I know that everything is working OK.

Only downside is that the occasional Other Boat slowly motoring down the fairway behind you all of a sudden gets a cross-current that can be surprising.