I have a 1969 larson with a i/o 4cyl mercruiser. I think its a GM 2.5 or 3.0 liter. Hasn't ran in 2-3 years.
After many headaches I now have gotten it to crank but not fire. I dumped gas in carb, no fire. My spark tester shows no spark. I bought a new coil and plugs and a "tune up kit" that consisted of condenser, points, cap, and rotor.
Changed it all out and no change. I seem to have 5 volts at the coil, and the coil ground is good. I jumped 12v power to the coil, no change.
Is this some sort of safety boat specific over-ride preventing spark? I notice the engine looks like it's out of a car except for key boat safety conscious changes throughout like a goofy air cleaner/alternator/and fuel pump.
Christian Harris
This is my first boat.
Jacob Bell
Have you cleaned the carburetor also?
Does the boat have a "deadmans switch"? Aka a sort of plug you put in near the steering that is attached by wire to your clothing, which when pulled out kills the ignition?
Been working on a 1953 Evinrude that sat since 1995 myself
Kevin Scott
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Ayden Phillips
>coil ground is good You know the coil ground is the points right? If it has ground all the time then the points aren't opening and that's why no fire
Jordan Fisher
I was waiting to get the carb rebuilt, havent done it yet, no deadman's switch.
I see now that's the wire that went from the coil to the points. I checked it once and saw good ground. I'll crank it witht hte cap off to see if the points open.
Colton Collins
Possibly bad alternator if you have one? Or generally just corroded wiring/ground
Kayden Scott
OK OP here.
Checked the points(never had a car with points) they are supposed to contact lobe under rotor which causes them to open. They did not contact these lobes. Adjusted so it opens about thickness of match stick? not sure on spec.
It fires now, it will pop off a few cylinders and chug for a second but it won't stay running. This is with me dumping a couple ounces of fuel into carb each try.
I'm not sure if it's just the fuel system now or still an ignition problem as well.
Gavin Cooper
Sounds like it needs a little love. I'd change the cap, rotor, points, wires etc and then move on to the carb adjustment/rebuild.
Fiddly but not terrible to do.
Bentley Powell
change the cap, rotor, points, wires etc
I've done all that. I'll bring the carb in for rebuild tomorrow..
>I'm not even sure it has fuel in it.
Dylan Scott
Disregard, you already replaced I'm an idiot.
Try to find the spec for the gap of the points and the spark plugs. I guess it might be possible that the timing is off from the dizzy
Grayson Gonzalez
>fuel
Well go put some in it!
Angel Allen
I suppose I'll try that before a carb rebuild.
Logan Miller
>Adjusted so it opens about thickness of match stick? Holy Shit! They're supposed to be something like .017-.020 at the maximum lift of the lobe.
Nicholas Howard
Hmm, I'll see if I can round up some feeler gauges.
Xavier Edwards
I think the fuel pump is bad.
Joshua Rivera
I dumped three gallons of gas in the tank and cranked it for 10 seconds, did this maybe five times. No fuel at carb. I then took the feed line off of the fuel pump and put clear hose in it's place. I put end of clear hose in gas can and it wouldn't suck any out. I put my finger over tip of clear hose and could not feel any suction. I will order a new fuel pump and have the carb rebuilt anyway.
Matthew Richardson
I set the points to .018.
Easton Mitchell
Should fire with fuel down the carb then.
Unless it's flooded now or the plugs fouled out from before
Ayden Nguyen
It looks like there might be a internal fuel filter in this thing?
Noah Hughes
Filter in the carb is dry and rusty. Don't see anything there that would prevent the pump from operating.
Zachary Lopez
Could be a fuel filter in the fuel tank, or the pickup tube for the tank, but I think you are on the right track. See if you can hook up power directly to the fuel pump to test if it operates.