Why won't it start?!

[matthewwatts]

This boat... this boat... I wasn't born a patient man and this thing isn't helping. I have a 1988 Forester Phantom 164. It has a 3.0L Mercruiser with an Alpha out drive. I've had nothing but problems. I think I might know what my problem is this time but I want to run it by everyone first.

In an effort to fix problem #2123 with the boat I decided a carb rebuild was in order (after all... it was the only thing left to replace/rebuild). Got the carb back yesterday, bolted it on... nothing. The motor cranks and turns over but will not fire. Look down in the carb and there's gas. Gas shoots when you advance the throttle. I sent the throttle to wide open nothing. I took the spark plugs out and they were black and sooty. I thought "Hey, it's just been running rich for so long the plugs are fouled out. I'll just replace them!" So this morning, I went and bought the AC Delco plugs (marine specific) put them in, cranked the motor and hey... it started. But ran like crap. I couldn't get back to the carb quick enough to adjust the fuel mixture and now I'm back to where I started last night. A boat that will turn over but won't start. I pulled the plugs and looked at them. The tips were already black, but I figured that was probably normal for pretty much being in a combustion chamber. They weren't sooty, though. I replaced the distributor cap and ignition coil only a month ago. The slip neighbor next to me said that I should try two things and then it'll give me a direction to go to.

He said that I should pull out the plugs and pour a bit of gas in each hole, put them back in and start the boat. If it fires then I know it is a fuel issue. If it doesn't, then it's a spark issue. The neighbor said that even though everything is new it still could have a hairline crack causing the issues.

What do you all think?

 

[airshot]

Not enough information to make any type of quality recommendation so......start from the beginning....do a compression check, check for proper spark on each plug, not just any spark but a proper spark with a gage. Is the timing correct? Who rebuilt the carb and was it done correctly? Is the fuel fresh or leftover from last year? You stated it ran like crap then stalled out before you could reach the engine, typically with the recommended settings for mixture adjustments on a fresh carb they are close enough to keep it running even though it may be a bit rough. Is the choke working or stuck closed? The spray from the accelerator pump in the carb should be quite strong in that 3.0, if weak you would have a problem. Fuel filter clogged. fuel line clogged, fuel pump working at proper pressure? I could go on but until these things are defined we are only making an abstract guess.

 

[Watermann]

Fuel, air and fire. If it won't start one or the other is missing. Since air is abundant lets rule that one out. Don't bother with pulling the plugs to test if it's fuel, remove the flame arrestor and put about a table spoon of gas into the carb throat, remove the gas container from the boat and try starting it. If it runs and stumbles again then you're not getting enough fuel to keep it running. Report back on the results after priming it.

 

[matthewwatts]

Not sure if this is the exact same, but... while starting we did spray starter fluid into the carb. Also, at a few points in time when priming (advancing the throttle forward 3-5 times) there was gas sitting on top of the two valves in the carburetor.

 

[Eric 3.7LX Alpha 1]

You replaced the cap and coil a month ago, how about the other ignition parts in the cap? The points and condenser?

It seems like I'm typing this a lot lately, but what's the gas look like? pump some out and dump it in a clear container like a mason jar and compare it side by side with another mason jar of fresh good gas. How old is the gas in the boat?

 

[matthewwatts]

I actually have been running it some this season and have probably gone through five or six tanks of fuel. I did look at it, though, just to be sure it wasn't a dirty fuel problem and it looked like it was supposed to.

I had someone change out the cap and coil. I would assume that all of the other parts, points, condenser would have been changed also since it is a new cap. I pulled the top off and it looked new to me.

 

[Bt Doctur]

have you checked the firing order 1,3,4,2 clockwise and the point gap?

 

[Watermann]

Sounds like you have plenty of fuel going so onto fire now. What I usually do is put my tester on the coil terminal with the key on to see if there are 12v there before moving onto tearing things apart.

 

[philipp10]

Listen to waterman, you need to determine if it is spark, or fuel related. Take off the spark arrestor, pour in some gas, then try and start it. If it fires, you have a fuel issue. If it does not, then look at the spark. Stop replacing parts, old fuel etc and start thinking, either fuel, or spark. That is the key.