Rough running 350

[1954bmw]

My experience with mechanical fuel pumps is they either work or they don't. They fail to work. I've never had one that was intermittent.

Not with this boat, but, I have a Bayliner 3888 Motoryacht with twin 270 horse 350 Chevys, (I hate small block Chevys), anyway, it had quadrajet carbs and one of them was pissing fuel down the carb, had carb rebuilt, same thing, new floats, same, ended up putting Holleys on it, now it's pissing fuel, ends up, the fuel pump was putting out TOO much gas pressure. Been a mechanic since the 70's, never saw a fuel pump put out too much fuel, either it pumps or not, not this one, boat mechanic replaced it. Not saying that's whats happening here, just saying.

 

[Jimway]

Sometimes, when things get aggravating, one must walk away for awhile. Troubleshooting should be done with a method approach. It is a skill as much as art. Don't check one filter, check them all, period. The second the thing wouldn't start, pull spark arrestor from carb, look at accelerator pump jets and manually pump throttle arm a couple of times, watching for a squirt of fuel. No squirt equals no fuel, and a place to start. If carb is full of fuel, move on to ignition. Remember that you need three things to run, 1. fuel. 2. compression. 3. ignition (at the right place and time). That's it. Since this thing runs good when it runs, I think you are looking at fuel or ignition. And now, a short story. Picked up a jet boat from under a pine tree. Spent some enjoyable time cleaning it up, getting it running, going through it, etc. Take her out for sea trials and she's hot to trot. Do some final tuning and she's turn key. Mrs. Jim and I spend the morning cruising here and there and even get in some skiing with it before it slowly dies like it was throttled slowly back to idle. No start but fuel in the carbs. We paddle back toward the dock before eventually getting a tow from a fellow boater. Home we go. Of course, when we get home and get the hose hooked up, the vessel starts right up before I can even start on the ignition system. Kind of hard to fix something that works. We go back to the lake for the evening. Lo and behold, after a couple of hours, same thing. This trip though, I hooked up a battery of portable test equipment. We have fuel but now no spark. I take a jumper wire from the battery and run power straight to the ignition. Nothing. I raise my eyebrows and look at Mrs. Jim. She shoots me a sultry glance and asks if we are going to spend the night out there. Lucky I brought some blankets. I continue working on the boat. After thinking about it for about the same time it takes to enjoy a cool beverage, I disconnect the ground wire from the ignition system that is used to kill the ignition. BAM, she lights right off. We head for home and the shop. After looking for awhile and bypassing components, I found that the safety lanyard switch had enough crud in it that it shorted out after awhile and shut down the boat as if you had turned off the key. Once that it had cooled down, it would work again for awhile. It was like a $20 part. Disassembly and observation under magnification showed that electric current was tracking across the corrosion on the terminals inside the switch. Salt water and it's ingredients are conductive.

 

[PA-Checkmate]

I would think "ANY" knowledgeable mechanic and doesn't need to be marine can figure it out which maybe a fuel or spark issue. If my boat I would put a fuel pressure gauge inline with the carb. Start it and watch the PSI... if it drops it's a fuel supply issue, if not maybe a spark issue..

Where do U live?

 

[todd goble]

Thanks guys this is a nightmare. I started it tonight. Poured some gas in the carb the first time it started and quit. Poured some more and the same. The 3rd time it stayed running, I let it idle and revved it a couple of times. Then I let it idle and then I turned it off. I did pour out the water separator yesterday to check for water. I think it had to prime itself. I am going to take it out tomorrow, didn't tonight because nobody was around to come and save me if needed. I'm from Pittsburgh but the boat is at Deep Creek Lake Md.

 

[Jimway]

Dang, why couldn't it be Oregon or Idaho? I'd come on over with some test equipment and we could spank the gremlins right out of that boat.

 

[todd goble]

Just my luck with this boat right now!!!! I wish we could knock this out. That would be awesome.

 

[todd goble]

Well the boat is in a better place. A Mechanic off the lake and I think he is really good ( I hope) I will give a update when it is done and healthy again

 

[todd goble]

The latest on the boat. The mechanic said he thinks its the coil, he put a new one in and is testing it this week. If it is the coil I will be pissed because I had it out and called a electric store that tests them and the guy said for every 100 he tests maybe 1 is bad. So I decided not to put a new one in. I hope to hear soon if it is it.

 

[1954bmw]

And you had the one in a hundred, thank you for the update.

 

[Jimway]

 

[todd goble]

Fuel Leak

I cant believe I am back on here about my vision 221, Got everything going and now have a fuel leak on my tank. Took the boat to the landing and started it and put up the hatch to check things out and gas was on top of the tank. Shut it down and started to check it out Cant find any fittings that are leaking or hoses. Every time that the bow is up gas is on top back of the tank, it seems to come from under the tank . How would I tank the tank out if it comes to that? Is that a cut the floor thing or what. No idea what is going on

 

[PA-Checkmate]

did the coil fix the running issue, or couldn't due to fuel leak?

 

[todd goble]

YES it did runs awesome again until this fuel leak started

 

[Jimway]

UGH- OHH, Craft is not airworthy at this time. My first thought is that you have raw fuel in the engine compartment and possibly in the hull so we aren't starting the vessel or making sparks of any kind at this time. Drain tank. Pull sending unit and look inside tank for possible corrosion. My next thought (after making sure that there isn't a bunch of fuel in the hull) is to procure a couple of outboard fuel tanks, plumb them in and enjoy some boating, five or six gallons at a time, while the weather is permitting. Attack fuel tank issue at leisure or perhaps as a winter project. When not in use, park vessel with bow as high as possible and see what drains out of open bilge plug. Let's hope that a bunch of fuel is not in the lower reaches of the hull. You could verify integrity of fuel line from tank to pump with a small amount of compressed air....

 

[1954bmw]

Jimway, agree with your idea of the portable tanks, what do you think of squirting some Dawn dish soap in the bilges and running some water thru it with the nose in the air, maybe clean it out some????

 

[Jimway]

Baking soda, vinegar, and water will work too. Got to get rid of all of the spilled fuel though. Hopefully there is not a whole bunch of it in the hull. I'm guessing the tank in the vessel in question is aft and somewhat enclosed.

 

[todd goble]

thanks guys for the information again. I like the portable tanks, we have 1 week left of family time and then kids go back to college (we hope) Yes the tank is enclosed in the floor UGH

 

[Jimway]

Hey, maybe it's something easy like a cracked anti syphon valve. Fuel is pretty handy at finding its way around loose fittings or failed gaskets and o rings. We keep a couple of those outboard motor tanks around for just such an occasion and when concealed fuel systems are giving one the fits.

 

[todd goble]

I hope it is something simple like that, I am getting it pressure tested hopefully tomorrow. How hard is it to hook up outboard tanks while I am going through this in order to run the boat

 

[Jimway]

Just run the line from the tank line to the fuel pump, usually have to cobble up an adapter depending on what tank you come up with. Do tie the fuel tank down so that it cant fly around. Keep it in the open so that you don't get any fumes from possible venting collecting in the bilge. The newer (pain in the backside) tanks kind of self vent and are kinda cool, they have a splashless connector, the vent/pressure cap, and a demand valve to help keep fumes to a minimum. I think we have a couple of old Mercury six gallon tanks and a larger one that is like twelve or eighteen. Works out pretty good when chasing fuel problems and they dont leak when getting sloshed around. The pressure bulb is super convenient to get fuel to the pump for prime.