1993 4.3lx bad coil?? help!

[ChrisCashman]

Alright I'll start with some background I bought the boat earlier this year for a good price, it had sat for a few seasons but had been winterized per owner. It was non-running when I got it. I was told by the owner that it was low hour and they had just lost interest in it. first thing i did was dump a little fresh gas down the carb and it popped right off. next i drained all the gas out of the tank. changed the fuel filter and added a can of seafoam. I also changed engine and drive oil and the raw water impeller. took it out for a short ride and it ran great. The next day we took it out and ran 15 gallons of gas through it no problems at all. and again I went for a few short rides. Me and the wife went out all day in it last weekend and ran probably 25 miles, not all at once. on the way back to the launch I noticed above 4k it would bog down. but I didn't have time to mess with it. took it out by myself a few days ago went for about 20 miles straight and it started to run rough and continued to get worse kind of seemed like fuel starvation, it would bog down and then come out of it and bog right back down again. like someone was turning the key on and off each time getting a little worse. I figured the 25 year old fuel pump gave up and changed the pump and put another new filter on. then yesterday I got up and took my for the same 20 mile trip it ran great all the way to the ramp then I noticed it was doing the same thing again. it was really notable at WOT it would cut out then come right back each time getting a little worse. it was almost as if someone was turning the key on and off each time getting a little longer. I'm thinking coil, but I'm not sure. just looking for further ideas on trouble shooting. per temp gauge boat doesn't overheat and has 14 volts on the battery gauge. Any guidance would be great!

 

[achris]

It's RARELY the coil. More good coils are swapped out every day than fail in a decade... That said, I actually had a coil failure, so I wouldn't rule it out. What I would be looking at would be a fuel issue, especially if it only occurs at higher revs. Very likely the carb needs to be pulled and given a thorough cleaning.

Chris..........

 

[Scott Danforth]

only about 3 out of a million coils changed were actually bad

if the motor runs, generally its not the coil.

if your coil is leaking oil and hissing like a snake, then I would say it would be the coil.

since you got the boat from sitting for 4 years, did you physically and mechanically clean all the goo and crud from the tank, if not start there.

look at the stickies for troubleshooting low WOT it will have the following and a bunch more:

do a compression check
empty the contents of your fuel filter and check for water and crud
check your anti-siphon valve, its probably plugged from the crud in the tank
pull your carb apart and clean it

 

[ChrisCashman]

I did drain a healthy amount of nasty fuel and changed the fuel line because it was old. I think I will work on pulling the tank next, it's just a wierd problem because it doesn't show up till after probably a healthy hour of continuous running. I did also take the anti siphon valve off and clean it, when I changed the fuel line.

 

[ChrisCashman]

well I think I have it figured out. I had myself convinced it was the coil. It did have a bunch of green shmu around the wire going to the cap, as stated it wasn't the problem. pulled the carb and apart and it was pretty clean for the age of the boat. Next I pulled the draw straw out of the tank and alass and draw straw was plugged solid. Of course I broke the anti siphon valve off in the draw tube fitting. so waiting for a carb kit and some new parts from Amazon and I hope to be set. Thanks for pointing me in the right direction. I appreciate the help.

 

[wahlejim]

A lot of the gunk from old gas will float in fresh gas. As you suck the fuel level down, thats when it starts to get drawn out of the tank. Sounds like this is what happened here.

 

[Scott Danforth]

no need to pull the tank

pull the tank sender
use a hand pump, drain the goo
dispose of per local requirements
mop up what you can
pour in 3 gallons of lacquer thinner
install tank sender
go for a 20 mile drive down a crappy gravel road
pull tank sender
use hand pump, drain the goo
dispose of per local requirements
mop up what you can
pour in 3 new gallons of lacquer thinner
install tank sender
go for another drive down the gravel road
use hand pump, drain the goo
dispose of per local requirements
mop up what you can
pour in 10 gallons of boiling hot water with dawn dish soap
install tank sender
go for another drive down the gravel road
use hand pump, drain the goo
dispose of per local requirements
mop up what you can
use air hose to dry out tank
install tank sender for last time
fill fuel tank with fresh fuel.

 

[achris]

That's a lot of gravel roads. Here in Australia we have this new invention, asphalt, they pour it on gravel and make a nice smooth road. You people in America should look into it. ...

 

[SandPiper66]

I don’t even own a boat (just dreaming right now), but get so entertained reading these threads!

 

[Bondo]

I don’t even own a boat (just dreaming right now), but get so entertained reading these threads!

Ayuh,..... Welcome Aboard,......

 

[ChrisCashman]

Tank is very easy to pull but its about 9/10s full, I ordered a few spin ons and now that I know where my stop up was i will run it down as low as i can and pull it and clean it real good. should of done this to start. but the wife wanted to get on the river.