fast_randy Loc: Blackfoot, Idaho

I've had the worst luck with my boat and trailor this year. But this is the third time I have backed it in the water and it will crank, but no fire. It is a 2014 40 hrs Mercury on a 16 foot aluminum boat. But this time I just got it back from the shop here in Blackfoot. They said they turned it and replaced the fuel filter. Well I had replaced the fuel filter before I took it to them because it would not start. I'm an idiot for not starting it at home and testing it after, but took off down to Utah to catfish. And that makes twice this year I have got down there and it would not run. It's a 3 1/2 hour drive.
I got it the winter before last. And used it a lot last year. It always fired immediately. I have a plastics gas tank. And sometimes as it sits in the sun, it blows up like a baloon, and becomes almost round. I let the pressure off by loosening the gas cap. And always run with gas cap half loose so it can breath, but tighten it to travel. Today at the lake I took the fuel filter off. It looked fine and after I put it back and squeezed the bulb the filter bulb filled right up with gass. (to be continued)

fast_randy Loc: Blackfoot, Idaho

Could the high gas pressure of the bloated plastic tank be a problem? Or cause some sort of high pressure limit to be tripped?
The first time this spring when it happened, as I tried to start it, the ring or nut that holds the ignition switch had come loose on the drive and I had to tighten it and wiggle the wires around and it started. But when I got way out to an island in the lake and tried to come back it wouldn't start and I barely made it back with my electric.
I went home and replace the ignition switch and it started right up and worked fine for several trips. But now won't run. Cranks fine, I charged the battery after I got it back from the shop. I don't believe they ever got it going at the only boat shop here in Blackfoot. And charged me over $200.00
I do think it is electric and not a fuel problem. Is there somehow it is getting power to crank but no power to the the spark plugs? I can't even figure out how to pull a spark plug to check if it is getting spark? Has anybody had this problem, sometimes it runs, sometimes it won't?

Grizzly 17 Loc: South central Pa

Hi FR. For some reason they decided not to put vent caps on tanks. They will swell up way up. I found 2 6gal that had cap vents. Pull the plugs n check then. If they have gas on them it's a spark issues. It they are dry you have a fuel problem. Pull plug put wire back on it. Turn it over ck for spark. You can hold a tester on plug n check for spark. If you can't see it wait for dark. Then there is the ever popular hold the plug. I choose not to do that👍

NoCal Steve Loc: Dunnigan, CA

Wish I could help but all my experience is with older 2 cycle motors. Grizz gave some good advice to find out if it's fuel or spark.

Pixiedog456005 Loc: Maryland

Grizz is right. Check for spark. yes-fuel problem. no-check for electric coming to coil.

Jeremy Loc: America

Don't fill tank so full. leave cap slightly loose. High pressure fuel is not the problem.

Probably need to check ignition leads inside the engine cover. May need to scrub some corrosion on all connections. may need to replace a primary ignition wire or terminal.

Someone else had a similar problem with a Mercury and it was the distribution box inside the engine cover.

It is an electronic distributer and controls primary ( 12V ) side of the ignition system. Look real close at all electrical terminals and wiggle them.

CHECK THE FOLLOWING FIRST.

You said you wiggled the Ignition switch / start switch and it changed it could be a bad connection or broken wire right where you wiggled it and results changed.

Fredfish Loc: Prospect CT.

Randy, check the kill switch and the wires going to it. They kill the ignition,but not the starter. Good luck buddy.

Grizzly 17 Loc: South central Pa

Gmorn Fred . You're right there. I've accidentally turned it off. Give you a oh crap moment. .😱.

fast_randy Loc: Blackfoot, Idaho

Thanks all for your suggestions. I just had new spark plugs put in at the shop, supposedly. But I will try to pull one and check. This gives me some thing to try today. Thanks again.

Grizzly 17 Loc: South central Pa

Good luck Randy. Fuel n electronic problems can be a pain👍👍

fast_randy Loc: Blackfoot, Idaho

Fredfish, you hit it. There is a tiny on/off switch that I had no idea was there under the throttle foward/ reverse handle that was off. I new someone here could help me figure it out. That couldn't have been the problem the first time I was at Utah Lake this spring. But it was now. I take back the bad things I thought about the shop here in Blackfoot. I fished from the bank down there for a couple hours. Got lots of white bass and one cat.
Thanks everyone for your help.

fast_randy Loc: Blackfoot, Idaho

My cat from the bank.

Ugly fish Loc: W Penn

Does that motor have some sort of a deadman switch as we are all required to have now on less than 20’ boats?

fast_randy Loc: Blackfoot, Idaho

Is that what it is called? Mine is a 16 foot Lowe. It's so small it is hard to see. Definitely a kill switch. I bet I never forget about that. On my boat, the only place I can put stuff where it won't blow out is in front of the driver seat, right by the throttel control. Like small packs and tackle boxes. So putting that in the boat could be tripping that switch. This is my second year with this boat. Thanks again Fred.

Rayz Loc: North West N.J. and South Hero Vt.

Of it is carbonated try spraying some started fluid into the engine. If it gets to run but stalls it likely is a fuel problem