Boat won't start!!! Need it for tomorrow morning!!
 

So we are in the process of dewinterizing our 4.3L Merc carburated engine. It will not start. I'm pretty good with car engines, how different can this thing be?

Here's what I've got so far.

-12 volts cranking power.
-It has spark
-Fresh fuel in the tank
-Engine turns, but only cranks, doesn't seem like fuel is igniting.
-Plugs are black/covered in oil (fogging oil?)
-Spraying either in the carb does nothing


I think it is a fuel issue. I don't exactly know how to check the fuel filter/system for a clog without dumping gas into the bilge.

Any ideas? Help!!

Boat won't start!!! Need it for tomorrow morning!!
 

This might seem obvious, but is your 'kill switch' enabled on the throttle?
If it is, you can crank engine all day and it won't start.

Just trying to look at the obvious simple things first. Especially, if the engine was running fine before it was winterized.

Tried starting fluid ?
 

While I'd guess you're correct re:fuel when you say you spray the carbs and nothing happens it then looks like a spark issue. Some starting fluid into the carbs should get you at least a cough or 2 when it ignites. Still if you looked and saw a spark at a plug .... ????

FWIW : I don't think the kill switch, or neutral safety switch, being activated would allow the engine to even crank, let alone make a spark so my take is that (those) aren't the problem.

Definitely getting spark. Pulled one out, forgot to ground, and zapped myself. :laugh:

Kill switch is fine. I've tried all different combinations of pumping the throttle lever and trying to start at different positions--nothing.

I took off the flame arrestor and noticed black "gunk" under the butterflies at the "floor" of the carb, with what look like little particles in them. I'm getting close to pulling the carb and cleaning it.

Fuel that sits in the carb float bowl all winter goes bad, volatility is lost. To start my Harley in the spring I first drain the carb float bowl to get the bad gas out. Then it starts right up but if I did not drain the bad gas first it is a real pain.

I don't know if you can easily drain your carb.

I noticed when I disconnected the throttle linkage, when I snap the throttle to WOT, fuel comes out the jets like normal.

So I'm thinking something with the carb, or maybe the fuel filter?

Stabilizer WAS added and run through the engine during winterization. But the engine right now is "running" off fresh, new fuel.

Pull a plug wire put a spare plug on it (or remove a plug), make sure it's grounded and see if you get sparks when you crank. You should get some type of ignition when you spray ether in the carb, which I don't recommend doing ever. It takes a lot of voltage to get a spark, it doesn't as much to get zapped.

A common 2-stroke starting problem: Old, fouled plugs
 

The oil is probably dissipating the spark. You should be able to SEE the spark.

You gotta SEE the spark. With fuel flowing as you've got it now, begin working on a spark plug angle.

"Zapping" is not the same as seeing a spark.

Just as a matter of long practice, I wouldn't touch the throttle unless gasoline has been in the carb fully for a day or two. The carb contains flexible parts designed for full immersion in fuel. Those can dry out and later rip. If you're getting normal fuel flow, then you most likely have a spark problem. I think the problem will be solved with a set of new spark plugs: At this late juncture, even one new plug that fits will get the engine started.

If the engine is still reluctant to start, remove one old plug altogether and crank the engine. The lowered compression load will increase the cranking speed, improving the opportunities at which compression and spark can spin the engine by itself.

Sail fast, live slow!

I have a t-shirt with that phrase!

Use your sails!

Case closed!
 

Guess when I winterized the boat I didn't run it long enough after adding Sta-Bil. The jets were clogged and the carb couldn't get fuel. So to be safe I pulled the carb, took it apart, and cleaned it. Put it back on and it worked like a charm. Yessssss!!! :D

The spark plug did fire and "pop" when I got shocked testing. Definitely worked!



Thanks for everyone's help!

Glad to hear you got her running. Job well done! :)

Winnipesaukee, make sure that you water test the boat, take her for a spin, before you bring any passengers aboard.

You 'da Man!
 

Winni:

Nice job of the carb! Isn't it great to be a GUY!

John Steinbeck once wrote ("Once there was a war") about two transport companies. One British, one Yank. When a british lorri broke down the tomies would transfer the goods to a good truck and move on.

When a Yank "duce and a half" broke down the Boys would find some bailing wire, a toothpick and a used can and make it run.

They would be proud!

See ya when you get wet!

Misty Blue

Glad you got it running, but the suggestion to pull a spark plug and ground it to see if you had a spark, made me cringe. All that cranking probably left the bilge full of gas fumes and an open spark could possibly be the end of your boat and a hazard to anyone close by.

The blowers were running during the whole process and before any start attempt two noses ran a "sniff" test. No worries!

Thanks again.

APS, haha, yes, I heard, felt, and definitely saw a spark!:laugh: