starting problem on gasser

[UNIQUE_NAME]

port engine sputtered and quit on sunday night return trip with 10 people on board. (427 ford chris crafts). been running great all summer.
yes, it was a LOOOONG ride home.
anyway, new cap/rotor/plugs and timed in the spring, mabe 15 hours. friday the exhaust sounded loud/odd on startup but performed fine on the trip out. sunday at startup exhaust sounded loud/odd again and this time warmed to a slight bit higher than it's normal temp. (usually about 160). exhaust water flow seems equal to the stb side. about 3 minutes into the trip the engine drops from 1500 rpm to 1000, stumbles and quits.
now the engine backfires and hesitates while cranking. i pulled all the plugs. they are gapped fine and look good with only #8 having light carbon. oil level and color are good. antifreeze has no oil and is proper level. checked the carb, i'm getting fuel. dumped the filter, fuel looks good. swapped dist cap and rotor, same results.
(no points/condensor insides are pertronix). new coil, same results. external resistor looks ok. the contacts inside the port cap appear to be charred as was the tip of the rotor. the stb cap/rotor does not have this discoloration. any ideas are welcome.

thanks,

jim

[krush]

Did you check for good spark?

You said no points....that mean you have electronic ignition? Switch over the module from the other side if it is easy. Also, if electronic ignition, sometimes the trigger takes a crap (thing that replaces points).

Ignore what I said if you have good spark.

Fuel is easy to solve lol get a squirt can and feed down the carb...have a large towel on hand to smuther in case of backfire.

[garyd]

Spark and fuel make it go bang. Timing makes it go bang at the correct time. Compression makes it have a bigger bang.

Since it is going bang it figures right quick you have spark and fuel. Next thing to check is the timing. If you can't do anything with the timing the timing belt has gone away. Yes it still could be a screwed up electronic ignition part so change them from side to side to see if the problem switches sides.

If the timing belt is good then there is an outside chance you flattened the cam.

I would suspect timing cause it can change temp albeit slighly and can change the sound again slightly.

good luck garyd.

[(Nobody You Know)]

May need to rebuild carb.

[krush]

Timing belt???????? crazy talk

Flattened cam...never heard of that one. Sounds like that would create a lot of metal pieces though.

[MikeP]

Sputtered and quit while running is a typical fuel problem symptom and that's a logical thing to check.

However...

Retarded ignition timing will increase eng temp and would cause a different sound in the exhaust. Did the idle speed change during the few days you were noticing the differences? If the timing changes, the idle will change (slow down if retarded, speed up if advancing). This could occur if the distributer housing was loose and able to rotate. Backfiring (through carb or through exhaust?) USUALLY indicates a timing problem as well.

So based on the description I'd agree with others and look at the timing. First I'd check the timing. If it won't start then you will have to check it staticly (sp?). There SHOULD be instructions on how to do that - they should have come with the ignition module. It's a lot easier with points!
As Krush noted, elec modules sometimes fail so swapping distributers or modules might be in order.

Bad ignition wires could cause some of the symtoms as can misrouted ones but unless someone changed them while the boat was running, misrouted seems unlikely. But it's possible that a wire may have contacted the ex manifold and shorted or intermittently shorted to ground.

The 427 ford does not have a timing belt, it has a chain as God intended engines to have. It's extremely unlikely to be a cam timing problem.

[Boatsb]

Its the muffler bearings.


Ok lets try again. It sounds weird and runs rough. Since there is no timing belt on 427 fords I would say look at the timing chain. Last I remember the cam was geared to the distributor shaft and they all are driven by the timing chain from the crank. Gary was on track but had the wrong descriptive.

I would check for distributor alignment with the crank and the cam. If the distributor is off it cold be the chain skipped a link. Also could be a bad valve/head but you need to start somewhere.

[bobk]

My son lost two fuel pump diaphrams on big block Crusaders with in an hour of each other. Symptoms were similar to yours. He confirmed the pump was the issue by pulling the pump drain hose and found loads of fuel squirting into the carbs. We are guessing this was related to use of gasahol. Engines are 1985 or so and this is the fisrt season for gas/alcohol.

Bob

[spartonboat1]

If you pull any fuel systems apart HAVE MANY fire extinguishers handy. I have been involved (sorry to say) in several industrial fires and gasoline fires are the worse yet on a fiberglass boat (solid gasoline looking for ignition source). In another life, I provided industrial safety...please you can't be too careful. Its why I love a diesel...a burning match will douse in liquid diesel fuel(not that I am going to try, mind you).

To ditto the others, 99% of the time, timing is the issue (no pun intended). Two sources are a timing chain that has jumped (rare- sign of a seriously worn engine, but easy to check with a wrench on the crank), a reluctor gone bad (makes solid state ignition "spark"), or a distributor that has been rotated to wrong position. If twas me, a good ole' timing light is in order. If memory serves me correctly there is no spark advance on a marine engine, so the timing should be "right on" and should not move around with rpm changes.

So use the timing light to check if you have spark (the timing light will not "flash", if there is no spark) and then check the timing against the timing marks on the crankshaft; if you have the specs.

Re: rebuild carb...over the years I have yet to need to rebuild a carb. Clean a carb yes, but they rarely need a rebuild. You should see the carb from my 1953 Chris Craft...looks like you could run over it and not damage it...heavy.

[Maynard Rupp]

OK hold it. That timing gear is not going to let the chain jump unless it has lots of hours. This is very uncommon on 427 Fords. The fuel pump thing is very possible. Look at the clear plastic hose that goes from the fuel pump to the carburator. These are on marine engines so that if the diaphram ruptures you don't pour gas into your oil pan. If you see gas in that line, you have a problem with the fuel pump. Remove the line from the carb, put a cup under it, and crank the engine. If fuel comes out at all, replace the fuel pump. You also talked about burned parts in the distributor though I am not sure if they were on the problem engine. Swap the whole distrbutor. You will have to re-time the engine, but that is a good idea anyway. If none of these suggestions cures the problem, you may have a partial blockage in my favorite *#$^%* check valve. Only gas engined boats have these. On our Hatteras it is one of the fittings between the tank outlet and the first piece of copper fuel line. It is part of the group of brass fittings that the tank fuel shutoff is associated with. Ours was the last fitting in the group and the one that the flared fuel line screws on to. Inside that is a spring loaded ball that prevents gas from siphoning into the bilge if a fuel line is broken near the engine. If that valve wern't there the gas could fill the bilge. Our valve on one engine feed was full of strands of glass and some varnish like leaves. That was enough to restrict our engine to low power operation only and would cut out at higher power settings. Of course it idled and ran great at low power. I think you said yours sneezes at startup though. Worth checking. Our other engine and genny feeds were clear.