Spewing Gas Into the Lake. Yeah Baby.

[EarlyWood]

'73 Mercruiser. It never ends. First time on lake this summer the boat overheated, somewhat extreme. Had the impeller replaced. Next time in lake, gimbal bearing rumbles, had that replaced. Put boat back in last week, had fuel problems, or so it seemed. She'd cut out when at full throttle sporadically (would run at slow speeds) and temp slightly above center line. Tonight she wouldn't start, dribbled gas into carb and got it going. Took it out, everything seemed fine but the temp gauge was showing she was running hot, not in red but close. Turned her off to let her cool. Start her up, run her hard and see that helped the temp but not much, had to shut her down again. Next, she didn't start, I had to be towed in but during the attempts to restart I noticed that she was spewing gas into the lake, it seemed to be coming out of the gimbal/transom ring.
WTF is wrong now!!!???

 

[erikgreen]

Re: Spewing Gas Into the Lake. Yeah Baby.

Are you sure it's gas?

If your gimbal bearing was bad, I'd suspect water in the u joint bellows might have got it that way... if that's the case the seal on the input shaft on the lower unit might be going too, and that would leak gear lube.

If you're sure it's gas, make sure you don't get sparks near the boat or engine until you find the leak and fix it. Check your oil for gas, check the tube that runs from your fuel pump to the carb for gas (there shouldn't be any) and check your bilge for gas... if gas is in the bilge the tank, sender, or fittings or hoses might be leaking.

Be careful... liquid gasoline anywhere but the fuel tank or engine is very dangerous. It won't just burn, the vapor can explode destroying your boat and you.

Erik

 

[EarlyWood]

Re: Spewing Gas Into the Lake. Yeah Baby.

it's def gas.

 

[EarlyWood]

Re: Spewing Gas Into the Lake. Yeah Baby.

http://forums.iboats.com/search.php?searchid=1910253

 

[Maclin]

Re: Spewing Gas Into the Lake. Yeah Baby.

What does the engine oil look/smell like?

 

[danond]

Re: Spewing Gas Into the Lake. Yeah Baby.

If it's overheating, something is wrong and "running it hard" isn't the solution. I'd get that fixed before something else goes wrong.

 

[EarlyWood]

Re: Spewing Gas Into the Lake. Yeah Baby.

my theory on running it hard (short time only) was that the new impeller was stuck or something was clogging the intake...was just trying to rattle things.
back to the question...the gas is not being burned and it's finding it's way into the lake out the back end somehow. I'm only seeing a gas slick (which dissipates quickly) when trying to crank her over. No gas in bilge. Will check the oil later today, but keep the suggestions coming

 

[Haut Medoc]

Re: Spewing Gas Into the Lake. Yeah Baby.

It would be helpful if you would post the engine model......
If the gas is not being burned, then it is not being ignited......
It sounds like you have multiple, unrelated problems.....
You didn't run the engine without supplying water to it, did you?.....

 

[EarlyWood]

Re: Spewing Gas Into the Lake. Yeah Baby.

she's a 73 4 cylinder 30-something (305?)
of course you're right about not firing/spark...actually had new plugs on hand intending to change but went directly for the gas problem seeing the newly changed the fuel filter wasn't filling, checked the fuel pump by disconecting intake line and dropping direct into a five gal tank, disconnected the line going to carb turned key and watched it work. Since I had some gas overspray laying around and on the engine I decided not to check for spark. Once I dribbled gas direct to carb this primed things enough to run continuously so I reconnected the intake fuel line to the primary tank. Took her out and then the overheating issue, non-starting issue, gas in the lake issue.
Still, if the plugs are not getting spark, how does the gas get pumped into the lake out the back end when trying to get it to fire up. And no, my bilge pump was doing nothing.
I'll be checking for spark later..but then there's the overheating issue. It's a brand new impeller. What's up with that?

edit..did not run without water..this was done in the lake

 

[erikgreen]

Re: Spewing Gas Into the Lake. Yeah Baby.

It sounds like you've got gas coming out your exhaust system.

Check your water intake line, the one coming from the transom and going to your circ pump, to see if the impeller is sending a good flow of water up the hose... don't leave it disconnected long, just a few seconds, but you should see a good flow of water in that time.

If the impeller is actually working I'd consider backflushing the system... it sounds like there might be a blockage somewhere preventing cooling water from circulating.. maybe pieces of the old impeller?

It does sound like you have multiple problems going on... the temp problem is separate from the fuel issue - if there's fuel getting to the carb, check the carb.

Has this boat been maintained properly, with annual oil changes, lower unit maintenance, etc? If it's that old it might need some long deferred maintenance.

Erik

 

[EarlyWood]

Re: Spewing Gas Into the Lake. Yeah Baby.

gas coming out of the exhaust? that's beginning to make sense, I guess, the unburnt gas being forced out the exhaust...

re parts of the old impeller...was kinda thinking the same since the mechanic who replaced it showed me the old one with every flange broken off. He said they turn brittle.. put my fingernail into it and didn't think this thing was brittle at all, but whatever..

this is so frustrating since last summer she ran like a dream

 

[Fishermark]

Re: Spewing Gas Into the Lake. Yeah Baby.

If the mechanic did not get the pieces out, you can guarantee they are plugging up something. Take your thermostat housing off and see if they are there.

Also - how long has it been since the manifold and riser was checked? That's a common cause of overheat.

she's a 73 4 cylinder 30-something (305?)

A 305 is an eight cylinder. If you have a straight 4 it could be one of several engines. See if you can find a serial number and post that. It will help others help you find the problem.

 

[EarlyWood]

Re: Spewing Gas Into the Lake. Yeah Baby.

it's a straight four...I just remember somewhere it being a 3something but I'll get numbers when I return to the frkn dock that I paid for all summer..
thanks

 

[Maclin]

Re: Spewing Gas Into the Lake. Yeah Baby.

I mentioned the oil because if it is running that rich to be passing raw fuel into the exhaust then raw fuel is getting into the crankcase as well and dilluting the oil. If it is indeed an over-rich leaking carb condition then oil/filter change is in order as well AFTER fixing the problem. In my opinion that is the only way gasoline would be exiting the transom, either via idle relief ports or leaky exhaust bellows right at the transom mount. And rubber bellows will not like any concentration of raw gasoline around or in them.

 

[EarlyWood]

Re: Spewing Gas Into the Lake. Yeah Baby.

I'm thinking bad things.
I changed the plugs, she fired right up, ran smoothly.
Disconnected water line and it appears fine, drawing water from the lake.
Checked the oil......it looks milky like water is getting mixed with the oil. It was clear before putting her in after the gimbal bearing operation.
Took her out with an eye on the temp gauge..sure enough she climbed high again and I had to turn around, shut her down and once again, she didn't start.
Checked the oil again, milky and maybe a hint of gasoline.
I've got pics and will post when I get home to a reliable signal.
I feel like this is it considering the extreme overheating done on the initial voyage early this summer supposedly due to the old impeller. I hope I'm wrong.

 

[tx1961whaler]

Re: Spewing Gas Into the Lake. Yeah Baby.

Time to run a compression check on all cylinders. Post back what you find.

 

[EarlyWood]

Re: Spewing Gas Into the Lake. Yeah Baby.

someone wanted numbers. if these aren't the ones, there's more..

I love this boat.

maclin you're on the right track

 

[EarlyWood]

Re: Spewing Gas Into the Lake. Yeah Baby.

I don't mean to single out Maclin ... the oil is milky, though, and I think I smelled gasoline. Fishermark's suggestion to remove thermostat housing has my interest. I only removed the hose going to it to see the flow of water being drawn from the lake, but the water in the oil (or maybe its gas) is bothering me..a lot
Here's what I think without having a good mental picture of where and how the cooling water is supposed to flow. It ain't flowing where it's supposed to. Someone please tell me I'm wrong but I'm thinking the worst like something cracked internally due to the overheat of the initial summer voyage. I'm thinking this is allowing water to get misdirected. Both of the most recent times of overheating I would shut her down and not be able to restart. Are the plugs getting drowned with water?? When I removed the old plugs there were beads of liquid on them, looked liked water beads but smelled like gas (but a flooded spark plug is going to smell like gas anyway, right?)
I think all of the other issues have been solved (new impeller, the gimbal, ignition spark) and I'm now confronted with going back to day one when maybe I didn't shut her down early enough.
Someone please tell me I'm wrong. I guess that compression check (thnkx tx1961whaler) would tell me things. Never did one, don't have the special tools, am getting drained and flustered. She does run strong when running though.
BTW
My pics are coming up as question marks on my computer. Can you see them? Do the numbers identify my engine?

 

[JustJason]

Re: Spewing Gas Into the Lake. Yeah Baby.

you have a merc 120 engine

you need to figure out your water in the oil situation before you go any further. drain your oil and put it in a clear container and let it sit for a day and take a picture of that. If it was a severe overheat you could have warped your head.

everything else is tune up related.....

 

[BMOLCHANY]

Re: Spewing Gas Into the Lake. Yeah Baby.

When it rains it pours.