Merc 330 No Fuel to Carb

[Jack Rose]

OK, you guys have been quite helpful on this engine in other posts (see below), and I've been really slow in attending to it, but I'm back on task.

So, this engine hasn't been run in several years and appears to have very few hours on it, none in the water. I had some other issues with it which I hope I've resolved for the moment. And I've done the necessary things before trying to start it, changed the oil, plugs, rotor, distributor cap, oil and fuel/water filters, turned it over manually, oiled it manually, spun it out with the starter motor, etc.

It had about 10 gallons of old fuel in the tank, so I've disconnected the fuel line at the fuel/water filter and dropped a two foot line into a jug of fresh fuel.

I was initially able to start it and keep it running with starting fluid, and after a bit it will run smoothly on its own for several minutes, but then quit.

So, I'm thinking that I can eliminate the timing/spark issues and concentrate on fuel. That right?

The fuel pump pumps a steady stream of fuel when I remove the line where it enters the carburetor, so it appears to be getting fuel at least that far.

However, when pumping the throttle I'm not seeing a squirt of fuel in the venturis. Seems like I should, though, shouldn't I? It's wet in there with fuel/mist, but no stream pumping in.

I took the top off the carb thinking that maybe the bowl would be empty, or the needle valve or float would be stuck, but no, no and no.

So, should I be seeing a stream of fuel pump in when pumping the throttle? Is there a filter that may be clogged, somewhere after the fuel line enters the carb?

Anything else?

One other thing that I found curious. While the engine is running, it's blowing exhaust and water, as expected, out of the starboard exhaust pipe, but only exhaust, no water, out of the port side.

The boat is sitting on a trailer that's parked lower on the starboard side, maybe a couple inches lower, but I don't know enough about the coolant path to know if that could be the cause. Surely these things don't have two thermostats, do they?

Thanks for your help,

Jack

---------------------------
Inboard/1980 Mercruiser 330/almost no hours/1962 Century Coronado.
Previous threads on this engine-
Re-Commissioning "New" 1980 Merc 330
Stuck Mercruiser 330
Un-Stuck Mercruiser 330
Water in bell housing

 

[Jack Rose]

Re: Merc 330 No Fuel to Carb

OK, well yeah ... duh! There's an inline filter right there, right where I disconnected the fuel line from the carb, right where the word "filter" is cast into the housing, and right where the online Quadrajet schematics said it would be. Huh.

OK, so yes, it was dirty, maybe what you guys call varnish from old fuel sitting in it, but it wasn't as bad as I was hoping, just coated on the bottom thiird. Anyway, I cleaned it and its chamber out, put it all back together, fired up the engine, and it ran for a minute or so, long enough that I was about to proclaim "mission accomplished" (no political commentary, here).

But then it backfired and stopped. Subsequent efforts have yielded similar results, though I've never gotten it to run quite as long, and each time a backfire kills it.

By the way, my starting procedure, when it was cold was to pull back three times on the throttle and leave it all the way out. As it warmed up, I laid off the throttle pulls. And when it did run, it sounded pretty smooth, loping along like you'd expect; however, it never got over about 1000 RPMs, even with the throttle still all the way out. And trying to start it with anything less than WOT was futile.

Any ideas?

And what about the water only coming out of the starboard exhaust? Maybe that's a dumb question, but I'm new to this and can't find the answer with any web searches.

Thanks,

Jack

 

[towman818181]

Re: Merc 330 No Fuel to Carb

i would suggest a carb rebuild and fresh filters and gas tank removed and cleaned out

 

[Haut Medoc]

Re: Merc 330 No Fuel to Carb

I would say that the water ports are clogged with scale in the riser on that side....

 

[Jack Rose]

Re: Merc 330 No Fuel to Carb

Thanks, it's got a new fuel/water filter and I've cleaned the in-line filter at the carb. Are there others?

I've disconnected the fuel tank which I'm planning to replace, so it's "running" on fresh fuel from a jug two feet from the fuel pump.

As for a carb re-build, it's looking like that's more and more inevitable unless someone comes up with another plausible fix that would allow me to put that off.

As for scale blocking the water ports, I don't think that's likely since this engine has never been run in the water.

Thanks,

Jacck

 

[Jack Rose]

Re: Merc 330 No Fuel to Carb

Hey, it's late, I'm bored and I stumbled into this old thread of mine, so I figured that I would confess my problem, ask for forgiveness and promise to never be so stupid again (until the next time), all in the interest of thread closure.

I had talked to my race car building brother-in-law, several times, about these problems and followed his advice, and had even left him a voice-mail with the engine coughing and sputtering and backfiring in the background. But it kept getting worse and, eventually, I wasn't able to get it to start at all.

But finally, my new favorite brother-in-law came up for a Tennessee football game (don't get me started on Lane Kiffen) and insisted that we climb into the boat and figure out what the problem was.

He immediately noticed that the points weren't opening. Not at all. And even though I insisted that I had gapped the points properly, and even though the set screw was nice and tight, and even though he had actually heard the engine running on the phone, he couldn't figure out for the life of him how I had gotten it to run, even as poorly as it was.

Anyone care to guess?

While looking over his shoulder, and I still haven't 'fessed up to this with him, I realized that I had set the point gap with that little lubrication felt pad between the high spot on the distributor cam and the nylon foot on the points. Obviously, that felt pad had started wearing down immediately, and caused all my subsequent ignition problems.

So after properly gapping the points and rebuilding the top of the carburetor (which solved the fuel issue) this engine runs like a top. And it sounds rather bad ***, too. Just ask my neighbors who can't wait for me to get those twin exhausts underwater.

As for water only coming out of starboard exhaust, I'm hoping that's normal for this engine before it comes fully up to temp. After the engine has heated up for several minutes, it's like a second thermostat opens up, and both exhausts exhaust warm water at the same rate. Before, I had never been able to get it to run long enough to get it to come fully up to temperature.

I also had the fuel tank cleaned out. They actually cut the bottom out of it, steamed it out, then welded it back together. They also gave me about a gallon of what looked like a mixture of oil and rust and asphalt that they had removed from the tank. They said that that's not unusual, that many of the tanks they refurbish have the same grunge in them. So you might want to check yours if it's got any age on it.

Meanwhile, as for solving my neighbors' noise complaints, I've only had the boat in the water, still on the trailer, long enough to realize that the wooden hull leaks like a sieve. But thanks to a good bit of help from some of the wooden boat forums, I hope to re-launch it, for the first time in many years, by mid-summer.

And at that time, this engine may yet prove to be a bucket of rusted bolts, but so far, I'm encouraged.

Thanks for everyone's help in overcoming my early problems, and thanks for your patience with my ignorance on the later ones.

Jack

----------------------------------
Inboard/1980 Mercruiser 330/almost no hours/1962 Century Coronado.
Previous threads on this engine-
Re-Commissioning "New" 1980 Merc 330
Stuck Mercruiser 330
Un-Stuck Mercruiser 330
Water in bell housing